@@nigelsmith7366 I think that maybe the case even today(need to closely look at my XT and SLX cranks) atleast on there mountain bike cranks which cosidered pretty bullet proof all things considered. I get the feeling that its maybe a case of there flying to close to the sun interms of trying to get weight saving on there road cranks
After my second R8000 failed I went to 105, there's probably a reason stock is thin on the ground. It's reasonably priced and looks the part, so long as you dont mind the disparaging looks from guys in rapha hats with clicky cranksets.
I run non-Shimano chainrings on my 105. Sold my Dura-Ace as without the chainrings it’s only around 50g heavier than 105. Plus 105 comes in silver which is automatically faster.
Many years ago I worked at Boeing and the whole chart of metals and which one we could work next to each one was reviewed greatly with every single part we worked with. In my group we worked with titanium a ton and since most jets have aluminum and carbon fiber yeah...we used a ton of plastic buffers.
Excellent review of the electrochemistry of bikes. One point is that you don't need to worry about carbon fiber (graphite) being extremely cathodic. These oxidation/reduction reactions need the metals to be solubilized. This is the role of the electrolyte. So elemental aluminum become AL+2, iron becomes Fe+3. Carbon (C) is insoluble. So to complete, AL+2 oxidizes (anode) to Al+3 and Fe+3 reduces (cathode) to ferrous ion (Fe+2). You hit upon and important point of Al+3 and oxygen --> Al2O3 the white powdery crud that forms in the c section, expands and allows more water in and further non-cathodic corrosion. Sacrificial anodes on bikes won't work as you need electrical continuity throughout. On boats most corrosion is caused by electrical leakage from the battery and the sacrificial anode is used to ameliorate this effect. Coatings just seem to invite corrosion at the edges. Time to take the Princess towel into the shower with you.
Yes. Additionally: An insulator will NOT prevent corrosion. It just slows it down, because of the solubilization of the metals in the electrolyte. The ions mix in the electrolyte and then you have aluminium and iron ions at the other metal. However for bikes this might be slow enough. Additionally you need to be careful, because scratches can move the metal over the insulator, forming a "bridge" (direct connection).
I have seen exposed carbon fibres in cut CFRP lead to corrosion of aluminium. You do have to worry about carbon in terms of it causing corrosion of metals in contact with it.
Forgive my ignorance in the case that this is a stupid question. If I have an aluminium seatpost in a carbon frame, can it corrode? Does the anodising prevent it getting stuck? I was under the impression we should use carbon paste to stop seatpost a slipping, however if they don’t move, do we still need to put something on them?
You have done an accurate review. When I developed the crank in 2010, I tested adhesion and brazing in the same structure as Shimano. Six months later, the adhesive crank arm developed electrical corrosion and cracks began to occur in the miscellaneous areas. Eventually, it was concluded that the crank arm made by attaching two parts was not good, and we developed a crank arm using extrusion. In addition, BB was developed as BSA+30mm at that time, and ACB of size 30.15×41×7 was used for bearings. That's right. This bearing is a headset bearing for 1.125" It passed the EN14766 test without difficulty, and the field test also showed a solid and soft feeling.
@@djlinux64 his name is Japanese, this is a video about Shimano Dura Ace cranks, so he's obviously talking about the Aldhu crank and 'we' in this case would be Rotor, no? 🤣
@@djlinux64 I was a product developer of the brand "Fierce" in Korea. While developing a hollow crank arm, we manufactured it in various forms and tested it. Among them, there was also an adhesion method, so I talked about the experience. If you list the specifications of the crank that was developed at the time, the length of the crank arm was 165/167.5/170/172.5, the hollow crank arm using the extrusion process, the integral BSA-30 BB&spindle, 40/24 chaining, 167mm Q-factor, total weight 685g. sale was not exported overseas only in Korea.
When this first started, the crank cracking, I thought it was a 6800 Ultegra thing because the new model is coming out since it has been running from 2013 with no failures then suddenly a lot failed in 2017. But the new models even Dura Ace suddenly started dying and me on 105 got scared for it's life despite the crank being 105 5600 lol and then I heard old hollowtech is the good one.
@Allan In person, I've seen 2 6800 fail, 1 R8000 and the rest I saw on social media. I've since then "upgraded" from a 172.5 5600 105 to a 165 4700 Tiagra and despite the weight penalty, the bikefit is much better and I think that's more important.
Shimano have used this strategy on many products since they started. It’ll get looked at when doing the next product refresh, but they are too committed to the tooling, etc to change. Cheaper for them to just be quiet and warranty the failed ones.
@@codycanning5300 I doubt they’ll do anything when they refresh their lineups. We’ve all got the same issues in mountain biking we’ve been complaining about for over ten years now.
The VERY reason I run 105 Cranks. Thanks for bringing this back in focus and not letting Shimano off the hook. All of your videos are highly anticipated. Great channel, Thanks for all you do.👍
@@paulruffy8389 They are not constructed the same at all. Hollowtech crank arms on 105 are not bonded. Shimano doesn't tell you about the difference sadly.
@@larrymcgoldrick3471 I have actually just "upgraded" to a Ultegra crankset from 105, just as the the 105 was marked up and the gearing is 6870di2. But makes me wonder whether I shoulda just kept the 105 crank
Now we know where all the Great Barrier Reef coral has gone, its in Shimanos cranksets. I've had 5 friends here now break numerous sets. Very common in Asia, humidity. I wouldn't say the Rotor Aldhus are a faultless. The way they clamp the spider or power meter on a tapered spline is really dumb as its so heavily reliant on perfect tolerances. Paul looks mental but i like his desk.
This was your best review by far and a well presented case Hambini . As a keen cyclist myself, the more you explained the reasons with the science behind it all, everything kept on becoming clearer and clearer. It was excellent ! I have had a Dura Ace 9000 split just as you described and was totally Peed off with the failure. It seems so unfair that the extra price you pay for the bling stuff is made this way.
The price you pay is for lightness, not durability. This is why it's recommended to NOT get dura ace accept on your race bike, if you have different bikes, otherwise, Ultegra or 105 for putting on tons of miles and time.
@@budviser3793But every reviewer and bikeshop I’ve listened to says you’re paying for lightweight and INCREASED durability as you go up the tiers in groupset. It’s all marketing ballshit aye
I have had 2 sets of Ultegra's fail for this exact reason. One set of the 6800's and the other the replacement 8000 series. The 8000's only lasted about 1½ years before failing. I live on the Gulf Coast of Florida so the electrolytes are everywhere in the air here. And, like you Hambini, put out the power of an F'n shrimp. I know someone that was "on it" and using Dura-Ace cranks and those cranks snapped. He hit the deck and shattered his hip. :( I can't give too many details as I know he has contacted a lawyer and a suit has been filed.
@@ironmantooltime I switched over to a set of ROTOR Ahdul cranks and would have to say it is the best set of cranks I have ever owned. And they look damn sexy on my TCR.
Total agreement - exact same thing happened to my Ultegra 6800 crankset after 5 years, thought it was a BB creak. It was almost an overnight failure after a wet ride. Got a 105 crank and it looked real solid. Recommend it all day.
I worked at FSA for a while and I am sure you are aware of the same type of failure in older K Force cranks due to galvanic corrosion. In those the spindle would come out of the drive crank arm. They dealt with it by changing to a glue for the spindle to arm that stopped the corrosion. I wanted to mention your comment about a recall. That will not happen until the failure becomes greater than 1/4 of production and results in at least half of that failure resulting in injury.
Not a part designer - chemical engineer, with an old specialization in materials (not practicing in material field at this moment). I agree that this looks like chemical corrosion all the way in. My guess when I saw the photos a year or so ago was that water was infiltrating somewhere in the bond and slowly eating away at the join. If Shimano can't bond the cranks in a hermetic way, maybe add a sacrificial anode somewhere in the piece? Adds weight for sure, but maybe not a stupid thing given the mess they got themselves into. EDIT: Also - great news on the Hambini BSA 30 BBs. I deliberately chose the 24 Rotor for my last build because I was fed up with SRAM's clunky preload adjustment and a bike that needed a bit of spacing help on the chainring area. This opens a lot more options.
The thing is if you add weight via a sacrificial anode, then the crank might become so close in weight to the lower tier (105) that it makes almost no sense for the upper tier variant to exist since the "upgrade" is predominantly about weight savings.
@@DilbertMuc dub works just as well, but SRAM also made 30mm bb30 cranks for awhile. Dub is 29mm and pretty much the same deal just with proprietary BB standards.
I came here to watch it because of the recall. Then, "I have a power output of a shrimp, and I managed to break it.". 🤣I am still laughing and confess I am training hard to get to shrimp level someday. The video is perfect, and you do an excellent service to cycling. 5 years old, sir!
weight weenieism is really stupid for this exact reason. You're much better off going for something more aero than getting the lightest bike possible unless all you do are uphills
I agree. If need or want a weight reduction, I need to eat less and ride more!! I have never been one to worry about a few grams here or there. - Cheers
Wiggle tried the 'out of warranty' shit with me. Turns out consumer protection relies on a reasonable person test and a failure at 2y2m isn't reasonable for an Ultegra component that is essentially monolithic. Madison agreed with me when I contacted them directly and basically forced wiggle to replace it. Mine failed and tore across the back piece.
I am always amazed to find people attaching aluminum to steel or, for that matter, embedding aluminum in concrete. It's pretty basic engineering knowledge that galvanic corrosion results when these materials are in contact with each other. Ages ago I worked for DART in Dallas and when they took over the bus system (to expand coverage etc.) they needed new signage. There was a desire for the posts holding the bus route designations to be something "nicer" than a galvanized steel pole. They chose a square cross-section aluminum pole. It looked quite nice. Within a year of deploying these poles across the metro Dallas area, they started falling over. Turns out they were installed in concrete bases and the corrosion was so extreme at the point where the poles touched the concrete the base of the poles basically melted. Needless to say, the DART engineers were dumbstruck because they were never consulted. Had they been, they would have pointed out the aluminum had to be isolated from the concrete. Steel, especially galvanized steel, does not have this problem with concrete. This is like finding out buried water lines to my home installed a century ago were lead... seriously. Lead.
Shimano (and others) used steel axles in aluminium cranks for a long time. They don't corrode. I'm not sure this is the reason for the failure. if the glue detaches and opens the insides to humidity, it will corrode. And obviously it would detach where at the most stressed location, which is near center of rotation.
Why is it so delightful to hear that shouted introduction? You know it's coming... And who can't be entertained by 'The Pen Is Working'. The always authoritative engineering presentation is the thing that makes it all so wonderful. Aluminium is extremely reactive and that very fact saves us all having our aluminium items exploding and catching fire due to the instantaneous oxidation of the surface which is very stable,. Steels have a wide range of reactivity, some rust as you look at them and some don't, esp of course the stainless alloys.. Which you just explained as I wrote this.. Doh.
For galvanic corrosion to happen on the anodic aluminium alloy, the locality where corrosion happen, needs moisture covering, and the same patch of moisture, has to extend to the cathodic iron alloy, to form a complete circuit for -OH to move to anodic Al, and +O to move to cathodic Fe. There could've been some physical opening around the glue bonding line (due to glue dispensing line not forming a close loop), allowing water to sip in, especially alkalic soap water used in bike wash. And then alkalic moisture stays in the hollow chamber. (You may test this out easily at home: have your used dura ace/ultegra dismantled from bike, remove chainrings & pedals, dunk it in a large bucket of water, and gradually turn it around, look for air bubbles carefully) Easier to observe air bubbles if you have cold crank and warm water. For bonding to happen at optimum strength, it is quite a norm to apply bonding primer on both aluminium surfaces. At times, primer could be corrosive on AL alloy. When aluminium hydrosite forms on the inner wall, it creeps horizontally along weak structural layer (like lawn weeds), depends on how the structure is formed (cast, forge, mold, extrude, CNC etc). And it physically expands. This expansion weaken the metallic surface adjacent to the glue. So it ends up the same: delamination happens and the two halves crank separated. The bonding glue did not reduce in strength, it's the metallic surface that it's holding, got weakened.
My experience with the Ultegra 6800 crankset is that there is a gap round the back of the spider where moisture can get in. This was my reasoning why the bond had failed on my unit. I also noticed that the R8000 I replaced it with did not appear to have a gap / was better sealed, but the instances of failure are still there it seems.
@@essjayaitch It’s a challenge bonding complex contour such as a crank. Based on Hambini’s review, it seems shimano is not matured in bonding process, where one of the critical parameters is to ensure consistent gap for consistent adhesive thickness. Without this facilitated by design, failure may happen in various locations and through various ways/modes.
Super impressed with the video and it confirms what I felt was the case already. I can CONSISTENTLY, and I want to stress consistently, have one of these cranksets fail approximately every 15 months of my normal use. I suffer from hyperhidrosis and live in hot humid Alabama. I have had two replaced and have the third on the bike downstairs and am no longer using it. My ANTIQUE 5500 series Shimano cranks are beaten to hell and back and still work. I started religiously disassembling the crank every month or so and cleaning the area between the R8000 spider and the chainrings and even lubricating them. Nothing helps, nothing will stop it, just like Hambini said. Local bike shop and local Shimano representative who happened to be present when I took in the second one feigned surprise and shop suggested I clean the bike more often. Can’t really do more than every time I ride it! Currently on an FSA branded heavy crankset which seems like it will last and had purchased a set of 105 5800 cranks to permanently solve the problem. Because I clean it so much I have caught both of mine when early cracking of the body occurred rather than full separation. I do think it’s worth considering the 105 option carefully. I have not looked at one first hand but the R7000 105 cranks look bonded as well. The old 5800 are not bonded and seem likely to last. That is what I will use next even though I admit the new R7000/8000/9000 look much better. This has been a big letdown for me regarding Shimano. I have had full confidence before but this is ridiculous and needs to be recalled.
People who can afford to pay for this are top 0.1% rich. I don’t think most really care about this being a disposal part that fails under extreme conditions. I personally won’t care if this could fail since I don’t live in humid area and don’t ride like a pro at all time and all I care is that blink factor. For pros, all they care is weight and performance, durability has to sacrifice. It’s a trade off.
I had exactly the same problem which turned into a full catastrophic failure across the spider itself. It failed on a climb during a race, not much fun. I thought that my bottom bracket was creaking but obviously it turned out to be a crank failure. I did manage to ride / nurse the bike to the pub safely, so not all was lost.
@@coreygolphenee9633 Fair point, but I don't know if Shimano do a track version of the 9100 series? (i.e built & assembled in the same way). Does seem that the failure mode will lead to an unexpected freewheel effect though, so possibly not OTB... (crashing to the floor probably very likely though :( )
@@neilbathe they still make the 7200 for NJS racing its a hittori Hanzo and a great reminder of what the company should be doing, but they could be trying to compete with SRAM omniums for a modern crankset and this is shit
In cars and trucks, rust expansion is called rust jacking. It's also common in general for steel lintels in houses. In cycling, aluminum seatposts corrode in steel frames. Removing one can be a monumental job.
Nice flashback to chemistry class! Yes, galvanic corrosion will occur in any two materials that have different electronegativity, especially in metals since they have so many free electrons I guess. Stuck aluminium seat tubes or stems on steel frames was (and still is) very common, but that is an easy fix, just grease it down thus creating an insulating cover. I have an oldish Sora crankset that sometimes creak, I thought it was the bearings, but now I'll have to really check!
jokes on the people thinking your power output is low. a shrimp's strike is about the most powerful in the animal kingdom, about 1500 newtons. their smashers have an acceleration of 10400 g (ten thousand four hundred times gravity force equivalent)
If you've not already done so, you should also discuss the reason the Shimano rear brifter destroys shift cables, causing them to fail inside the mechanism. This often results in a shifter that can't be saved.
Happened to a friend of mine with his Ultegra 6700 brifter. On a descent in the Alps. He instantly produced thousands of permanent grey hairs as a result from the stress!
Thanks for the video. My DA 9100 crank failed as well. The non-drive side delaminated and it was just outside the warranty period. I emailed the shop I purchased from with pictures and they just said, sorry and said I could buy a power-meter arm. Tried to find someone from Shimano to share this issue but could not. What a disappointment, I am glad I was not injured while riding.
I sold my Dura Ace crank and replaced it with a 105 after seeing #thanksshimano. Glad I did, it’s been on there for 2.5 years and a lot of hot sweaty turbo training
I enjoy your reviews. I have been a “hobbyist” bike mechanic and have done my own wrenching and bike building since working in a Schwin bike shop when I was in high school, some 50+ years ago.
Thanks for being tireless in your pursuit of the truth and letting the component manufacturers know that not anything goes. I've been following this particular case for quite a long time and I personally think it would suit Shimanos reputation if they were to recognise and admit to the problem ....and it would also set them apart from other component manufacturers in a positive way.... Maybe they could come to be known as the "Honest" component creator.... I know it's a long shot.. 🤓
Friends sent me the link to your video after I took a nasty crash and fractured my hands due to my crank shearing apart mid ride early this week.... Was on a duraace 9100 crank less than a year old. Just happy to be alive. Could've been worst..
All these comments are clearly missing the point of this video which is actually Hambini demonstrating his true calling in life as a photographer. The framing of the princess with the crank arm @18:50-19:50 is utterly perfect 🤣
Good stuff Frenchie! I've had both a Durace and Ultegra versions fail this way. Oddly they both failed around the pedal area, but still displayed the same characteristics. Give Shimano their due they replaced both.
When I stopped Cyclespeed Tours, I bought Marine Control SL in Mallorca. We sell anodes for boats.Typically we use zinc for salt water, aluminium for brackish and magnesium for fresh.But none is used 'pure' and is a cocktail of other metals too
This happened to 2 of my Shimano DA-9000 cranks - brought back memories - the infernal creaking, the trying to source the issue (seat/frame), the mechanics having no idea - saying the creaking was coming from the spider bolts (utter-nonsense) even replaced an almost new press-fit BB to no avail. Eventually visible failure occurred, luckily non catastrophic. I ride in the tropics so I believe the moisture has an effect but a few friends have had similar issues with both Ultegra and Dura-ace cranks. Tried to buy Rotor but no stock so eventually found another DA-9000 (like rocking horse sh*t during a Pandemic) which will probably die after 20,000km like the last ones. Spoke to Shimano here in Indonesia.....Sorry Sir out of warranty. Annoying as my opinion is it is not fit for purpose - the crank spider /arm wears out before the chainrings!! I doubt however Shimano will recognise their issue - is 9200 the same construction? Its a shame as I love Shimano functionality and performance.
People who can afford to pay for this are top 0.1% rich. I don’t think most really care about this being a disposal part that fails under extreme conditions. I personally won’t care if this could fail since I don’t live in humid area and don’t ride like a pro at all time and all I care is that blink factor. For pros, all they care is weight and performance, durability has to sacrifice. It’s a trade off. That’s the logic behind that design.
Well done and very informative. So many bike companies and retailers refuse to stand behind their products, just expecting cyclists to replace "worn out" items because it is past the warranty period. One thing I will say about SRAM, I own some RED products and SRAM has usually replaced them past the warranty period.
A local friend had his Ultegra 6800 crank split, so add that to the list. Guess don't get your Shimano cranks wet and keep them in a humidity control room with your cigars haha
Excellent analysis. High-end bike parts always push the limits between light weight and failure. Campagnolo cranks went from steel to aluminum alloy and then Super Record (1980s) got even lighter. Failures became commonplace in short time spans. Shimano 105 is a happy medium between performance and weight.
Abit of bad news for you- the rotor aldhu 24 uses a steel axle (the 30mm one uses an alloy axle) which is connected to the aluminium alloy crankarms (7075 or 6061 depending on whether its aldhu or vegast) by a threaded bolt (which I think is aluminium) so you're unlikely to run away entirely from galvanic corrosion here. That being said, the entire crankarm is anodised and the rotor crankarms are a solid machined billet of aluminium, so any galvanic corrosion problems are unlikely to be catastrophic. The most you might have is a crank that might be hard to get out- but a thin layer of marine grease on the mating surfaces should solve the problem.
Now I finally understand why the aluminum inserts for by bottle cage screws are corroding so bad on my carbon Trek Remedy. It is literally rotting away and I can't do anything about it. Thanks my favorite 5 year old for the awesome explanation!
I think the sheer amount of bonded dura ace and ultegra cranks still in warranty put shimano off from acknowleging this, can you imagine the bill if they were expected to proactively replace every crank in the same way canyon, specialised etc have in recent months when they acknowledged engineering faults. Had already decided Rotor would be my next crank, appeals to me anyway due to coming from a BMX background where 3 piece is the norm, just another good reason to go that route now!
My Ultegra crank cracked after year of normal use. Here in Lima, Peru. Shimano is replacing it, hope it lasts a little longer this time. Thanks for the video ¡
Thanks for the no-shite, serious engineering explanation of the problems that ill Shimano. It's not that they should know better - they already do. But they are ignoring potential disaster if they continue to keep their heads up their arses. This will not go away anytime soon.
They’ll start to give a shit when a crank gets delaminated in a big race. Imagine that happening in Flanders or the Tour … the PR disaster alone should make them care about it.
@@endcensorship874 You can bet that the cranks and other kit that Shimano sends to its sponsored teams get the pro peloton treatment at the factory before anything happens. Assume components such as the cranks are put through extra treatments, materials and assembly steps that the regular production trash never get. That and additional inspections and an insane QC rejection rate. Just assuming, of course. And wonder what special instructions the team mechanics receive, or are there factory-recommended service lives between replacements for certain components such as the cranks. And supposing that these practices by Shimano may be the case (because I'm just guessing), it would mean that somebody - or several people - knows what's really up with these things. And if people know, maybe somebody will talk. And if somebody talks, that would be very bad for Shimano.
@@RReese08 pros on big name race teams go through bikes and replacement parts like crazy. Failures are less likely if something is only a month old. Whereas it is not unreasonable for a consumer to keep a quality bike for many years and they aren’t having a pro mechanic going over the entire bike every day or 5 while being ridden by a heavier rider. A bike holding up for 2 months and parts replaced when only 10% worn by a 150lb/68kg rider with good technique isn’t nearly as impressive as being replaced at 50%-100% worn by a 260lb/120kg rider with poor technique.
OMG...That creaking noise was on my bike as well and I never figured out what it was until watching this video. I know it wasn't the bottom bracket because I had one of your bottom brackets installed. I then thought my frame was cracked somewhere but I couldn't find it. Long story short my bike was stolen so the issue went unsolved until now. Thank you for making this video.
Loss of face to admit failure is likely a contributing factor to S’s inaction - as a practising lawyer they are setting themselves up for a class action, not only for a defective product, but also a PI claim should your final premonition become a reality.
A little off topic but I had a number of crank arm failure years ago when riding top of the line forged Campy cranksets back in the 80'a. I had three separate failures on cranksets that were supposedly under warranty. The first time the local bike shop gave me a replacement crankset and send it back to Campy. The second time a year later the replacement failed and they replaced it again. The third time the shop would do nothing because they said Campy rejected the second one and they never got paid. When I said they were under warranty they told me to sue Campy because the shop was not taking another loss None of those failed forged Campy cranksets had ever had a crash and were in nearly mint condition. They all failed under hard pressure either sprinting or climbing hills and caused crashes. People need to realize when their cranksets are under pressure and fail (no matter what the brand or model) it is like stepping of a cliff and and you either instantly fall over or you stay up with a damaged arm pointing up with the good arm under pressure pointing down. In one of my failures the later happened and my shin turned in and the upward broken arm sheared right up my shin and cut me very badly and I had to tie a bandana around my leg to limit the bleeding. On top of all that I had to ride hope after all the crashes and injuries using just one good crank arm. After the third failure I switched from Campy to Shimano Dura Ace and never went back and have it on multiple bikes although only three have Dura Ace 9000 components (the rest are older 10 speed series). I have never had the Shimano failures described in this video but I did have a Shimano Dura Ace crankarm that I had a hairline crack through the pedal hole that I noticed before it failed and they replace that crankset under warranty but it took awhile to get it. I would suggest that people regularly clean and inspect their bike components and frames (I have had some of them crack and fail as well) so they can catch problems before they become serious and cause failures out on the road. I learned the hard way.........................
Had this happen with my Ultegra, actually sent you a note about it. The fact that they for sure know it's happening, and haven't done anything about it yet, is just dumbfounding. Really interested in the new 12spd stuff and how that is going to hold up.
Makes a lot of sense. Had a pair of Oval Concept 950 alloy clincher aero wheels, original equipment on my Fuji Norcom Straight and wanted to centre them as the spokes also felt a bit too loose. When I started to adjust the tension I realised that no matter how hard I tightened some of them, no effect. Then I had a closer look and realized that more than half of the spoke holes inside the rims had cracks, most if them several millimeters long. In general, the overall, apparently not even anodized alu part of the wheels was covered in corrosion products very similar to the ones in the Shimano cranks. I always wondered whether it is good design that when cycling in the rain, water was getting into the rim and it gurgled around it in there until after about a week, it finally evaporated. Now I know what else it did in there than just making funny noise. Steel aero spokes in direct contact with aluminium in dirty water - guaranteed desaster. I was lucky that I found the cracks before the wheels collapsing while driving. So, contact corrosion seems to be a problem generally underestimated or ignored by component manufacturers.
This is your GREATEST ever video Mr Hambini-man!!! As a passionate and committed CAMPAGNOLO devotee - you can't imagine the absolute pleasure Shitmano's product failures are giving me! LOLOLOOLLOLOL!!!! PS. Point of interest - whenever aluminium and steel come into contact, they create an extremely aggressive electric reaction - as you quite rightly stated, a kind of 'battery [Galvanic] effect'. This is also known as 'electrolytic corrosion' - which produces a whitish powder residue. Electrolytic corrosion was very commonplace with automobiles [especially during the 1950's and 60's] when car manufacturers started using aluminium and steel body panels together. Indeed, it became such a problem that rubber beading had to be inserted between the surfaces of the two metals to prevent them coming into direct contact. Unfortunately, the rubber beading would rot away after a few years and car owners would suddenly find entire areas where steel wings came into contact with aluminium bonnets and boot lids for example, totally corroded away.
Yeh, well you should see the 'reaming' he gave Campag too. My Shimano cranks have never failed, but then I'm not daft enough to lean my bike against a central heating radiator and not realise how harmful that is to bonded components be they hollowtech or carbon.
I bought a De Rosa Idol with Campagnolo Potenza, best bike I ever owned with the worst groupset I ever owned, an absolute pile of shit - Within 500 miles the right shifter snapped and the bottom bracket sounded like a ratchet with all the clicking noises it was making. I've no idea why Campy insist Potenza is comparable with Ultegra, it simply isn't... maybe Claris or Sora but no higher. ChainReaction couldn't resolve the problem and wouldn't swap the groupset to Ultegra so I ended up with a refund :( Shame as ignoring how crap Potenza was the bike was beautiful to ride and the thumb shifters I absolutely loved
bought a 105 because of this and its still going strong. also using steel bearing BB also due to what I learned here. my previous ceramic bb spoiled at 100km.
Hambini, go for Hope’s 30mm all aluminium road crankset! I have fantastic experience in last two years. Very well made but pricey. I personally had issues with modern Rotor crank (it was Vegast crank model with 30mm alu spindle). It was creaking a lot from the start, which I thought had to do with DS side spindle spline tolerances, which caused creaking in the spider/ring (one piece) interface. It drove me mad and could not get it to work.
Mine failed on winter bike on Saturday, Ultegra R8000 Been well aware of the issue so check the crank/chainring for gaps while cleaning the drivetrain after every long ride. Went without warning just a pop/clunk while out of the saddle. Starting to separate in the centre and a crack forming on the crank arm behind the small chainring😠 Fortunately didn’t totally fail as still had 40+ miles to get home
Instead of talking crap, as i mostly do here, I will give some background to your comments; Did a vid on this and the short answer is, Shimano is not admiting this problem exists ( as a design problem). As to the corrosion, they is a number of issues there. It is not just about steel and aluminium, but if you have big swings in temperature, the dew point changes. This means you could have a partially saturated air in the crank at manufacturering. But when the temperature changes the moisture becomes free in air and the cycle of corrosion starts, making an electrolyte for the corrosion. Starting the process, although it maybe fully sealed. As to fail safe. The key is the unwanted outcome, i.e. you have a domestic charger pack with a transformer in it. The unwanted outcome could be that it catches fire 🔥. If the tranformer failures, and it either doesn't catch fire or cause the plastic surrounding it to catch fire. It is deemed to fail safe. These tests are pretty general for domestic products in western countries and these tests are defined by Mandatory Standards.
10:04 If the hidden endcap is not an integral part of the spindle and merely assembled on, then it shouldn't be bonded. micro-movement induced by pedaling torque may form opening/crevice at this endcap and resulting moisture ingress. Or, alternatively, there's pre-existing gaps at the joints between steel spindle and forged base spider.
Guess it kinda shows how bad cycling industry is with admitting fault, even Japan. Hell at the moment with the Toyota Yaris Cross there's a recall for all vehicles happening because one person hit a bump too hard, hit the inner wheel arch lining and it fell off.
Glad this video is up. My bike came with full 105 group set but not the cranks. Wanted ultegra but got 105 because the weight difference is sub 100g and stainless steel chainrings. But here is another reason to use 105 over higher end stuff
16:55 Just a small point. You are conflating "Factor of Safety" with "Fail Safe". Factor of safety is the amount of excess load a component can bear compared with its expected maximum loading in normal use. For example a SWL 10 ton rating lifting component (e.g. shackle) might have an actual failure rating in excess of 40 tons. This is called the safety factor. "Fail Safe" means that a component or system is designed such that in the event of a failure the component or mechanism does not represent a danger to users or other components in the system. An example of this would be a runflat tyre which is designed to stay in place on the rim in the event of a puncture or blowout. An example of "Fail Unsafe" - (fail dangerous?) is the RCD (Residual Current Device) on modern (UK) domestic circuits which protect people against electric shocks. There is no indication of a failure condition (which is why they are supposed to be tested regularly) and in the failed condition power is still passing through them with no shock protection.
Well done. The (few) carbon frames I’ve built all used alu inserts for headtube and BB. This allows for traditional bike shop tools to ream, face, and in the case of BB chase threads. These frames have all been equipped for standard BSA bottom brackets, which of course allows for external threaded bearing systems as well. Due to galvanic concerns, the alu bits are first wrapped with epoxy fiberglass as an insulator. I have no doubt that over time, particularly at the ends/faces, there is the possibility for galvanic corrosion. And eventually, this will likely be the primary cause for the frames ultimate failure. While I anticipate this to take some time, I don’t expect a CF frame to last as long as a typical steel frame. Now the methods noted above will not lead to record light weight frames. But I think light weight is way over rated. Especially because UCI weight minimums mean that record light frames aren’t necessary to hit UCI requirements. But, the fact is that the various concerns re CF and weight obsessiveness has lead me back to traditional steel frames.
Steel is good and aluminum is also good enough for my riding. I figured that galvanic corrosion would be the downfall on most carbon or bonded aluminum.
@@MartijnPeek I’m confused as to how that could happen. Don’t ions from both the anode (Al) and cathode (C) have to be soluable for the reaction to occur? I guess the carbon could act as a conductor to steel parts such as rivnuts which would then set up a galvanic circuit.
Luckily I wasn't sucked in by "lighter is better" with Ultegra or Dura Ace, and I went with 105. With that said, I worked as a crew on some Sportfishing boats in Hawaii, when we took the boats out of the water to redo the bottom, we also had to replace "the zincs" on the stainless steel shafts and rudders. I wasn't initially aware of the reason what they were or why they were on there, but was told by one of the captains that they are on there because of the electrolysis, and that they are designed to corrode instead of the steel (and aluminum in other places). In light of that, I wonder if it would be wise, or even possible to connect a small piece of zinc on area of the bike where 2 different metals are touching to prevent the corrosion of the softer one (usually aluminum).
@@coreygolphenee9633 My 105 set on the bike in my profile pic still works. The funny thing is that my TT bike weighs about 8.5kg and the bike in my profile pic weighs about 13kg. It takes me 230w on my TT bike to do 37.2kph and it takes me 194w to do 38kph on the bike in my profile pic. That is 36 watts difference. When I put 230w on my recumbent bike I am doing well over 40kph. All the DF riders talk about 100g here, or 200g there, internal cabling, waxing their chains instead of use any type of oil. But as soon as you tell them to move the parts around on their bikes to make it way more aero they get all weird. The UCI banned recumbents because they were too fast. I say "Fuck the UCI" ;)
@@casualguy393 I ride track bikes mostly and ill just that the hittori hangout NJS dura ace cranks, its my favorite part about track bikes is that if shell out dough for the nice stuff the components are ludicrously tough
So if you are looking at a Titanium bike frame, you really need to use carbon finishing kit to make sure it doesn't react as they are both fairly unreactive?
If you are worried about the contact between the Al bearings and Ti frame (don't know what other contact point there would be) just use a copper or silver based anti-slip on the threads. This was what my manufacturer (Serotta) advised.
@@massspike My friends front mech clamp failed on his Ti frame. A carbon clamp with a braze on style mech would avoid that problem. I think the sweat+Ti+Al+steel bolt caused the failure.
I've seen this problem a lot. I been thinking 🤔 lol wonder how accurate the power meter is while the front of the crank is twisting. But the twist is more from the failure causing false read outs....
Didn't anyone tell you never to go for XTR or Dura Ace? The advantages for amateurs in non existent and the disadvantages are massive. Great analysis by the way. Gives me lots af ammunition to give my Dura Ace friends a hard time.
I have the DuraAce 9100 crank so I'm a little worried about this happening to me. I also work in US aerospace. We commonly use stainless screws, washers, threaded inserts in combination with aluminum alloys (6061, 7075, 7050, etc). To minimize the chance of galvanic corrosion we apply primer between the faying surfaces to seal the joint. I'm surprised that Shimano didn't do the same thing between the axle and the crank hub. I would think that water would have to get in there to start the corrosion. How? I don't know.
This was very well done Hambini, (minimum of cursing); took me back to engineering meeting days. It's very likely the Japanese engineer(s) that created this fiasco had to shave their heads in disgrace. Amazingly though I did not hear you mention sweat as it can be one of the better electrolytes. And everybody sweats; granted some more than others... so even in a hot dry climate the presence of electrolyte is likely. Agree that shitmano should be recalling those crank sets.
I think that Shimano lost their way a bit after the 7800 series (which, personally, I still think is the most asthetically pleasing groupset they ever made) which seemed to be well designed and made from an engineering standpoint. Gluing carbon fibre together in this way is asking for trouble when exposed to thermal cycling and exposure to road borne contaminants (oil, salt, water etc.)
Not a fan of threaded BB personally. I just lost another frame, nice carbon bike from 2014 with a disbonded BB shell. BB386evo is such a nice combination of features, and it'll never have a shell disbonding failure :)
Unless it's an alu sleeve in there. Jokes aside, gutted for your loss. Threaded is good for maintenance but it may not be good for carbon since torquing up your bb may put stress on the alu insert and damage the bond(don't quote me I'm not a mechanical engineering undergrad, I'm a hospitality management undergrad lol) I only torque up my bb to 12-17nm and I've never had problems in 3-4 years.
@@dan_lazaro the aluminium sleeve is the problem, eventually all inserts will fail. (I've also never overtorqued the BB as it self tightens anyway). I disagree that threaded is better for maintenance, it's much easier to extract the bearing in a pressfit BB than to extract the bearing from a threaded cup, just eliminate the middle peice.
@@MartijnPeek I took it to the carbon repair place here and yes it would be possible but more than the frame is worth. Given its rim brake, no point repairing it.
What would be nice is to dig a bit deeper into Shimano's line of cranks and see if GRX groupsets are also affected. They look more like 105s but might as well make the PSA complete.
Have you had any reports of these failures on the latest dura-ace cranks released last year? I'm not sure if Shimano have revised their crank design and bonding process to address the issue or continue to produce more of the same. (The latest cranks are slightly heavier than the previous generation). I continue to use the earlier Hollowtech 2 generation cranks which are presumably welded/forged? Certainly there is no visual joints. I think that the later 105 cranks also have the bonded /cast design and presumably fail in the same way so going to 105 may not be the answer unless they are the older hollowtech 2. Shimano stuff is usually very good and hopefully they will eventually come up with cranks which do not break up, Until then I will stick to the older heavier Hollowtech versions.
The new 9200 DA crank is quite a bit heavier than before, so presumably they just beefed it up. But there are many lighter, better cranks out there than this supposedly 'flagship' model that costs a fortune.
Spot on. Thought it was a creaking BB, turned out to be the crankarm. First it was Ultegra, I moved to a DA but suffered the same fate. 2 crankarm failures in less than 3 years.
Great video, been waiting for this one to come out, does look like a design failure, wonder why they didn't dip the steel axle with coating to prevent the galvanic process between the steel and aluminium interface. I use Campagnolo cranks which seem to last forever, super record axle is titanium. Shame as I like the look of the Dura Ace crank but I'll be sticking to the Campag.
It has nothing to do with the construction itself. I have 105 crank sets which have thousands of miles on them featuring aluminum bodies and steel shafts. And I ride in Switzerland in the winter where the roads get treated with salt -> perfect electrolyte. So there must be something shimano effed up in the construction of the failing crank sets. My bet would be moisture creeping in somewhere and the oxides splitting the stuff open and loosening the bond. Bad anti corrosion concept. Finally the battery accelerates it for the "final sprint".
@@cls9474 "It has nothing to do with the construction itself" "So there must be something shimano effed up in the construction of the failing crank sets" Not sure I understand your point as it seems to contradict itself. Do you mean there is nothing wrong with using a steel axle with aluminium crank spider? True if there is something to prevent moisture between the two parts but a bike sits outside and atmospheric conditions will cause moisture on the inside of the crank arms. If Shimano used a barrier layer between steel and aluminium that would help. I believe 105 cranks are made differently to Ultegra and Dura Ace.
@@danbanham728 No, it doesn't contradict itself. The only difference is that the 105 are welded (no seam where moisture can creep into). Apart from that the construction is the same. Riveted steel axle on an aluminum body. And as I said: I don't know anyone in my bike infested circles who had any problems with the 105ers. I have a bike which I just maintained (just installed the 4th BB) with a triple 105 and same construction: Not the slightest issue. And I ride in the winter in the mountains with salty snow slush. For more than a decade.
@@danbanham728 Yep, but the battery exists on both. And that's what I'm talking about. The steel-aluminum design doesn't seem to be the problem as it seems to be managable. And that's your main point in your original comment.
Marine sacrificial anodes are generally zinc blocks, which are replaced on a fairly regular basis. They only work if any metal required to be protected, is in electrical contact with the anode.
Great vid I'd like to hear some pro road mechanic's feedback, I'm sure they've been dealing with it for years, Shimano in all their glory will say they've addressed the problem with their new 9200 series groupset and I'm sure mixing the metals and the corrosion will continue. I choose Rotor cranksets, 30mm axel and I love the modularity and just the superior machining and engineering.
Zinc anodes are what's normally used in boats. I've pop riveted (usually monel) many 316 stainless fittings to aluminium masts. I always provided a barrier between the steel and the aluminium. Plastic packaging tape, the really thin stuff about 50mm wide, seemed to do the job.
Although I have switched from my 6800 with sigeyi power meter to Aldhu 24, this is exactly what I'm waiting for. BTW, I found a lot of Chinese "CNC" cranks (dirty cheap, less 100 yankee dollars) with 24 mm axles (some thick 7075T6, some steel), all with SRAM 3 pin direct mount. Different preloading methods (from direct shimano copy to SRAM/Aldhu like preload ring). Some good ones (like the one from Fovno) weight only 515g (cranks + axle), only slightly heavier than aldhu 24. Any intention to review some of them?
I have the Fovno Phantom and the most common issue is there M14 bolt breaking. Also, there's no available M14 bolt replacement to buy anywhere. Other than that, everything's really well done.
I think you just explained the creak in my TCR that I was never able to find which ultimately had me selling it and buying a Super-Six Evo. (yes, Hi-Mod, of course)
The conclusion to get a 105 really put my mind at ease, because (being a rider on the lower end of mediocrity) I could never justify spending more than 2k on a bike, so now 105 is what I have on both of them 😂
105 was my workhorse for my first 20 years on the bike. I fell for Dura Ace 7800, the last of the silver. 105 is still really, really, good. I have Ultegra DI-2 now but did not fork out for the cranks and kept my 105's. Happy days
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A link to the webpage accompanying this video is here www.hambini.com/shimano-crankset-failures-an-engineering-analysis/
We need to know more! Let’s have guest video from the gunman.
@@dominicward3523 I'm not sure I can find him.
Shimano's original hollowtech XTR cranks were welded and never had any issues.... It also looks like the top half is forged and bottom half is cast
@@Hambini Buried beneath the folds of MAB's manatee-esque arse, I should think.
@@nigelsmith7366 I think that maybe the case even today(need to closely look at my XT and SLX cranks) atleast on there mountain bike cranks which cosidered pretty bullet proof all things considered. I get the feeling that its maybe a case of there flying to close to the sun interms of trying to get weight saving on there road cranks
This aged quite well. Shimano just recalled these cranksets.
I came here to say this
I wonder if anyone is going to apologolize for pushing this crack.
They recalled all the 11-speed cranks; Ultegra FC-6800 and FC-R8000, and Dura Ace FC-9000, FC-R9100 and FC-R9100P.
After my second R8000 failed I went to 105, there's probably a reason stock is thin on the ground. It's reasonably priced and looks the part, so long as you dont mind the disparaging looks from guys in rapha hats with clicky cranksets.
There's no real winner at the Special Olympics. Buy a mountain bike, learn how to ride it, laugh at Rapha choppers. Job jobbed 👍🏿
Love the Rapha guys and gals... :)
I run non-Shimano chainrings on my 105. Sold my Dura-Ace as without the chainrings it’s only around 50g heavier than 105. Plus 105 comes in silver which is automatically faster.
does the r7000 new 105 have the same issue? or do I need to find an older r5800?
@@Demon09-_- r7000 is not bounded but forged, so the 105 should not have the same issue
Many years ago I worked at Boeing and the whole chart of metals and which one we could work next to each one was reviewed greatly with every single part we worked with. In my group we worked with titanium a ton and since most jets have aluminum and carbon fiber yeah...we used a ton of plastic buffers.
Glad I stuck with my 82’ Campy Super Record .. 40 years now with nary a hitch.
Excellent review of the electrochemistry of bikes. One point is that you don't need to worry about carbon fiber (graphite) being extremely cathodic. These oxidation/reduction reactions need the metals to be solubilized. This is the role of the electrolyte. So elemental aluminum become AL+2, iron becomes Fe+3. Carbon (C) is insoluble. So to complete, AL+2 oxidizes (anode) to Al+3 and Fe+3 reduces (cathode) to ferrous ion (Fe+2). You hit upon and important point of Al+3 and oxygen --> Al2O3 the white powdery crud that forms in the c section, expands and allows more water in and further non-cathodic corrosion. Sacrificial anodes on bikes won't work as you need electrical continuity throughout. On boats most corrosion is caused by electrical leakage from the battery and the sacrificial anode is used to ameliorate this effect. Coatings just seem to invite corrosion at the edges.
Time to take the Princess towel into the shower with you.
Yes. Additionally: An insulator will NOT prevent corrosion. It just slows it down, because of the solubilization of the metals in the electrolyte. The ions mix in the electrolyte and then you have aluminium and iron ions at the other metal. However for bikes this might be slow enough.
Additionally you need to be careful, because scratches can move the metal over the insulator, forming a "bridge" (direct connection).
I have seen exposed carbon fibres in cut CFRP lead to corrosion of aluminium. You do have to worry about carbon in terms of it causing corrosion of metals in contact with it.
@@gmt198 What redox reactions are you suggesting the carbon causes? And what is CFRP?
@@lb7325 Carbon Fiber Reinforced Plastics (or Polymers)
You have the fibers stick out at the cut end (especially at drill holes)
Forgive my ignorance in the case that this is a stupid question. If I have an aluminium seatpost in a carbon frame, can it corrode? Does the anodising prevent it getting stuck? I was under the impression we should use carbon paste to stop seatpost a slipping, however if they don’t move, do we still need to put something on them?
You have done an accurate review. When I developed the crank in 2010, I tested adhesion and brazing in the same structure as Shimano. Six months later, the adhesive crank arm developed electrical corrosion and cracks began to occur in the miscellaneous areas. Eventually, it was concluded that the crank arm made by attaching two parts was not good, and we developed a crank arm using extrusion. In addition, BB was developed as BSA+30mm at that time, and ACB of size 30.15×41×7 was used for bearings. That's right. This bearing is a headset bearing for 1.125" It passed the EN14766 test without difficulty, and the field test also showed a solid and soft feeling.
What crank did you develop? Was this one of the early cranks released to the public? Who is "we" in "we developed" ?
@@djlinux64 his name is Japanese, this is a video about Shimano Dura Ace cranks, so he's obviously talking about the Aldhu crank and 'we' in this case would be Rotor, no? 🤣
@@retardno002 those look like korean characters not japanese
@@djlinux64 I was a product developer of the brand "Fierce" in Korea. While developing a hollow crank arm, we manufactured it in various forms and tested it. Among them, there was also an adhesion method, so I talked about the experience. If you list the specifications of the crank that was developed at the time, the length of the crank arm was 165/167.5/170/172.5, the hollow crank arm using the extrusion process, the integral BSA-30 BB&spindle, 40/24 chaining, 167mm Q-factor, total weight 685g. sale was not exported overseas only in Korea.
@@retardno002 Haha... Not Japan, Korea.
It’s pretty amazing that this has been going on for so long and Shimano are like “move along, nothing to see here”.
When this first started, the crank cracking, I thought it was a 6800 Ultegra thing because the new model is coming out since it has been running from 2013 with no failures then suddenly a lot failed in 2017. But the new models even Dura Ace suddenly started dying and me on 105 got scared for it's life despite the crank being 105 5600 lol and then I heard old hollowtech is the good one.
@Allan In person, I've seen 2 6800 fail, 1 R8000 and the rest I saw on social media. I've since then "upgraded" from a 172.5 5600 105 to a 165 4700 Tiagra and despite the weight penalty, the bikefit is much better and I think that's more important.
Shimano have used this strategy on many products since they started. It’ll get looked at when doing the next product refresh, but they are too committed to the tooling, etc to change. Cheaper for them to just be quiet and warranty the failed ones.
@@codycanning5300 I doubt they’ll do anything when they refresh their lineups. We’ve all got the same issues in mountain biking we’ve been complaining about for over ten years now.
Yeah Shimano sucks period, honestly always has
The VERY reason I run 105 Cranks. Thanks for bringing this back in focus and not letting Shimano off the hook. All of your videos are highly anticipated. Great channel, Thanks for all you do.👍
105 same construction are they not? Hollowtech?
@@paulruffy8389 They are not constructed the same at all. Hollowtech crank arms on 105 are not bonded. Shimano doesn't tell you about the difference sadly.
@@larrymcgoldrick3471 I have actually just "upgraded" to a Ultegra crankset from 105, just as the the 105 was marked up and the gearing is 6870di2. But makes me wonder whether I shoulda just kept the 105 crank
On which series Dura Ace/Ultegra did they start doing bonded cranksets?
@@Knowbody42 9000/6800
Now we know where all the Great Barrier Reef coral has gone, its in Shimanos cranksets. I've had 5 friends here now break numerous sets. Very common in Asia, humidity. I wouldn't say the Rotor Aldhus are a faultless. The way they clamp the spider or power meter on a tapered spline is really dumb as its so heavily reliant on perfect tolerances. Paul looks mental but i like his desk.
You've got 5 friends? 😀
@@tednruth453 one of them works for Shimano which was awkward!
@peak torque my hairdresser and therapist agree with you. The desk is over 100 years old. And the typewriter is also nearing that age as well.
Can you imagine if this was a smaller brand? Everyone would be laughing at them and saying it's a death-trap. But... It's Shimano... Carry on!
@@ChinaCycling They'd say i t was a rogue supply of one and not a hambini special!
This was your best review by far and a well presented case Hambini . As a keen cyclist myself, the more you explained the reasons with the science behind it all, everything kept on becoming clearer and clearer. It was excellent ! I have had a Dura Ace 9000 split just as you described and was totally Peed off with the failure. It seems so unfair that the extra price you pay for the bling stuff is made this way.
This is exactly for blink factor and for competition only. It’s a trade off. Something has to give under extremely engineering to win competitions.
The price you pay is for lightness, not durability. This is why it's recommended to NOT get dura ace accept on your race bike, if you have different bikes, otherwise, Ultegra or 105 for putting on tons of miles and time.
@@budviser3793But every reviewer and bikeshop I’ve listened to says you’re paying for lightweight and INCREASED durability as you go up the tiers in groupset. It’s all marketing ballshit aye
I have had 2 sets of Ultegra's fail for this exact reason. One set of the 6800's and the other the replacement 8000 series. The 8000's only lasted about 1½ years before failing. I live on the Gulf Coast of Florida so the electrolytes are everywhere in the air here. And, like you Hambini, put out the power of an F'n shrimp.
I know someone that was "on it" and using Dura-Ace cranks and those cranks snapped. He hit the deck and shattered his hip. :( I can't give too many details as I know he has contacted a lawyer and a suit has been filed.
🦐Power!
Damn, fnck that! 105 till i die 🤟
@@ironmantooltime I switched over to a set of ROTOR Ahdul cranks and would have to say it is the best set of cranks I have ever owned. And they look damn sexy on my TCR.
Total agreement - exact same thing happened to my Ultegra 6800 crankset after 5 years, thought it was a BB creak. It was almost an overnight failure after a wet ride. Got a 105 crank and it looked real solid. Recommend it all day.
I worked at FSA for a while and I am sure you are aware of the same type of failure in older K Force cranks due to galvanic corrosion. In those the spindle would come out of the drive crank arm. They dealt with it by changing to a glue for the spindle to arm that stopped the corrosion. I wanted to mention your comment about a recall. That will not happen until the failure becomes greater than 1/4 of production and results in at least half of that failure resulting in injury.
Not a part designer - chemical engineer, with an old specialization in materials (not practicing in material field at this moment). I agree that this looks like chemical corrosion all the way in. My guess when I saw the photos a year or so ago was that water was infiltrating somewhere in the bond and slowly eating away at the join.
If Shimano can't bond the cranks in a hermetic way, maybe add a sacrificial anode somewhere in the piece? Adds weight for sure, but maybe not a stupid thing given the mess they got themselves into.
EDIT: Also - great news on the Hambini BSA 30 BBs. I deliberately chose the 24 Rotor for my last build because I was fed up with SRAM's clunky preload adjustment and a bike that needed a bit of spacing help on the chainring area. This opens a lot more options.
Try the 30mm cranks from sram, the preload adjuster is 10x better than the old wavy washer + hopes and prayers method of GXP.
The anode would just buy you some time, but when worn/gone, the crank would then fail as before.
The thing is if you add weight via a sacrificial anode, then the crank might become so close in weight to the lower tier (105) that it makes almost no sense for the upper tier variant to exist since the "upgrade" is predominantly about weight savings.
@@dvoob You mean the DUB cranks?
@@DilbertMuc dub works just as well, but SRAM also made 30mm bb30 cranks for awhile. Dub is 29mm and pretty much the same deal just with proprietary BB standards.
Came here for the Shimano drama, learned about the processes behind why my steel frame has an aluminum seat tube chemically bonded for life.
I came here to watch it because of the recall. Then, "I have a power output of a shrimp, and I managed to break it.". 🤣I am still laughing and confess I am training hard to get to shrimp level someday. The video is perfect, and you do an excellent service to cycling. 5 years old, sir!
Glad I went with 105. Never mind the weight penalty, I’m the heaviest bit when I’m on my bike.
weight weenieism is really stupid for this exact reason. You're much better off going for something more aero than getting the lightest bike possible unless all you do are uphills
I agree. If need or want a weight reduction, I need to eat less and ride more!! I have never been one to worry about a few grams here or there. - Cheers
Wiggle tried the 'out of warranty' shit with me. Turns out consumer protection relies on a reasonable person test and a failure at 2y2m isn't reasonable for an Ultegra component that is essentially monolithic. Madison agreed with me when I contacted them directly and basically forced wiggle to replace it.
Mine failed and tore across the back piece.
I am always amazed to find people attaching aluminum to steel or, for that matter, embedding aluminum in concrete. It's pretty basic engineering knowledge that galvanic corrosion results when these materials are in contact with each other. Ages ago I worked for DART in Dallas and when they took over the bus system (to expand coverage etc.) they needed new signage. There was a desire for the posts holding the bus route designations to be something "nicer" than a galvanized steel pole. They chose a square cross-section aluminum pole. It looked quite nice. Within a year of deploying these poles across the metro Dallas area, they started falling over. Turns out they were installed in concrete bases and the corrosion was so extreme at the point where the poles touched the concrete the base of the poles basically melted. Needless to say, the DART engineers were dumbstruck because they were never consulted. Had they been, they would have pointed out the aluminum had to be isolated from the concrete. Steel, especially galvanized steel, does not have this problem with concrete. This is like finding out buried water lines to my home installed a century ago were lead... seriously. Lead.
Shimano (and others) used steel axles in aluminium cranks for a long time. They don't corrode. I'm not sure this is the reason for the failure. if the glue detaches and opens the insides to humidity, it will corrode. And obviously it would detach where at the most stressed location, which is near center of rotation.
Why is it so delightful to hear that shouted introduction? You know it's coming...
And who can't be entertained by 'The Pen Is Working'.
The always authoritative engineering presentation is the thing that makes it all so wonderful.
Aluminium is extremely reactive and that very fact saves us all having our aluminium items exploding and catching fire due to the instantaneous oxidation of the surface which is very stable,. Steels have a wide range of reactivity, some rust as you look at them and some don't, esp of course the stainless alloys.. Which you just explained as I wrote this.. Doh.
For galvanic corrosion to happen on the anodic aluminium alloy, the locality where corrosion happen, needs moisture covering, and the same patch of moisture, has to extend to the cathodic iron alloy, to form a complete circuit for -OH to move to anodic Al, and +O to move to cathodic Fe.
There could've been some physical opening around the glue bonding line (due to glue dispensing line not forming a close loop), allowing water to sip in, especially alkalic soap water used in bike wash. And then alkalic moisture stays in the hollow chamber.
(You may test this out easily at home: have your used dura ace/ultegra dismantled from bike, remove chainrings & pedals, dunk it in a large bucket of water, and gradually turn it around, look for air bubbles carefully) Easier to observe air bubbles if you have cold crank and warm water.
For bonding to happen at optimum strength, it is quite a norm to apply bonding primer on both aluminium surfaces. At times, primer could be corrosive on AL alloy.
When aluminium hydrosite forms on the inner wall, it creeps horizontally along weak structural layer (like lawn weeds), depends on how the structure is formed (cast, forge, mold, extrude, CNC etc).
And it physically expands.
This expansion weaken the metallic surface adjacent to the glue.
So it ends up the same: delamination happens and the two halves crank separated.
The bonding glue did not reduce in strength, it's the metallic surface that it's holding, got weakened.
My experience with the Ultegra 6800 crankset is that there is a gap round the back of the spider where moisture can get in. This was my reasoning why the bond had failed on my unit. I also noticed that the R8000 I replaced it with did not appear to have a gap / was better sealed, but the instances of failure are still there it seems.
@@essjayaitch
It’s a challenge bonding complex contour such as a crank.
Based on Hambini’s review, it seems shimano is not matured in bonding process, where one of the critical parameters is to ensure consistent gap for consistent adhesive thickness. Without this facilitated by design, failure may happen in various locations and through various ways/modes.
Super impressed with the video and it confirms what I felt was the case already. I can CONSISTENTLY, and I want to stress consistently, have one of these cranksets fail approximately every 15 months of my normal use. I suffer from hyperhidrosis and live in hot humid Alabama. I have had two replaced and have the third on the bike downstairs and am no longer using it. My ANTIQUE 5500 series Shimano cranks are beaten to hell and back and still work. I started religiously disassembling the crank every month or so and cleaning the area between the R8000 spider and the chainrings and even lubricating them. Nothing helps, nothing will stop it, just like Hambini said. Local bike shop and local Shimano representative who happened to be present when I took in the second one feigned surprise and shop suggested I clean the bike more often. Can’t really do more than every time I ride it! Currently on an FSA branded heavy crankset which seems like it will last and had purchased a set of 105 5800 cranks to permanently solve the problem. Because I clean it so much I have caught both of mine when early cracking of the body occurred rather than full separation.
I do think it’s worth considering the 105 option carefully. I have not looked at one first hand but the R7000 105 cranks look bonded as well. The old 5800 are not bonded and seem likely to last. That is what I will use next even though I admit the new R7000/8000/9000 look much better.
This has been a big letdown for me regarding Shimano. I have had full confidence before but this is ridiculous and needs to be recalled.
People who can afford to pay for this are top 0.1% rich. I don’t think most really care about this being a disposal part that fails under extreme conditions. I personally won’t care if this could fail since I don’t live in humid area and don’t ride like a pro at all time and all I care is that blink factor. For pros, all they care is weight and performance, durability has to sacrifice. It’s a trade off.
I had exactly the same problem which turned into a full catastrophic failure across the spider itself. It failed on a climb during a race, not much fun. I thought that my bottom bracket was creaking but obviously it turned out to be a crank failure. I did manage to ride / nurse the bike to the pub safely, so not all was lost.
I ride mostly track bikes if this happened at any rate of speed its OTB
@@coreygolphenee9633 Fair point, but I don't know if Shimano do a track version of the 9100 series? (i.e built & assembled in the same way). Does seem that the failure mode will lead to an unexpected freewheel effect though, so possibly not OTB... (crashing to the floor probably very likely though :( )
@@neilbathe they still make the 7200 for NJS racing its a hittori Hanzo and a great reminder of what the company should be doing, but they could be trying to compete with SRAM omniums for a modern crankset and this is shit
In cars and trucks, rust expansion is called rust jacking. It's also common in general for steel lintels in houses.
In cycling, aluminum seatposts corrode in steel frames. Removing one can be a monumental job.
Nice flashback to chemistry class! Yes, galvanic corrosion will occur in any two materials that have different electronegativity, especially in metals since they have so many free electrons I guess.
Stuck aluminium seat tubes or stems on steel frames was (and still is) very common, but that is an easy fix, just grease it down thus creating an insulating cover.
I have an oldish Sora crankset that sometimes creak, I thought it was the bearings, but now I'll have to really check!
jokes on the people thinking your power output is low. a shrimp's strike is about the most powerful in the animal kingdom, about 1500 newtons. their smashers have an acceleration of 10400 g (ten thousand four hundred times gravity force equivalent)
If you've not already done so, you should also discuss the reason the Shimano rear brifter destroys shift cables, causing them to fail inside the mechanism. This often results in a shifter that can't be saved.
Happened to a friend of mine with his Ultegra 6700 brifter. On a descent in the Alps. He instantly produced thousands of permanent grey hairs as a result from the stress!
Thanks for the video. My DA 9100 crank failed as well. The non-drive side delaminated and it was just outside the warranty period. I emailed the shop I purchased from with pictures and they just said, sorry and said I could buy a power-meter arm. Tried to find someone from Shimano to share this issue but could not. What a disappointment, I am glad I was not injured while riding.
I sold my Dura Ace crank and replaced it with a 105 after seeing #thanksshimano. Glad I did, it’s been on there for 2.5 years and a lot of hot sweaty turbo training
105 is the best anyways
A black R7000 105 "the groupset of the people" crank looks better then Ultegra or Dura Ace.
@@redinho1994 are You kidding me? Dura ace is the most beauty Groupset. 105 is the market Group set for poor people.
@@kielond.3638 DId you even watch the video?
@@Diamond_Hands7 what video? Are You normal or No?
First sponsor segment I didn't skip, worth it 100%.
I enjoy your reviews. I have been a “hobbyist” bike mechanic and have done my own wrenching and bike building since working in a Schwin bike shop when I was in high school, some 50+ years ago.
Nice! My uncle is a Schwinn collector and mechanic. Lots of paramount’s and even old Olympic track tandems 😎
This video aged well considering the current recall of Shimano. Hope they learn from their mistakes
Thanks for being tireless in your pursuit of the truth and letting the component manufacturers know that not anything goes. I've been following this particular case for quite a long time and I personally think it would suit Shimanos reputation if they were to recognise and admit to the problem ....and it would also set them apart from other component manufacturers in a positive way.... Maybe they could come to be known as the "Honest" component creator.... I know it's a long shot.. 🤓
Friends sent me the link to your video after I took a nasty crash and fractured my hands due to my crank shearing apart mid ride early this week.... Was on a duraace 9100 crank less than a year old. Just happy to be alive. Could've been worst..
Your shrimp analogy really exemplified the problem for me.
All these comments are clearly missing the point of this video which is actually Hambini demonstrating his true calling in life as a photographer. The framing of the princess with the crank arm @18:50-19:50 is utterly perfect 🤣
Good stuff Frenchie!
I've had both a Durace and Ultegra versions fail this way. Oddly they both failed around the pedal area, but still displayed the same characteristics.
Give Shimano their due they replaced both.
I had one break at the spider and one just below where the pedal axle screws into crank arm
If it was made properly it wouldn’t have failed. High quality bikes used to be expected to last for 100,000 miles/160,000km.
@@stefhirsch6922 My first crank set lasted about 18K and my second broke at 7K miles. Both breaks at different locations.
I never thought I'd see a Shimano product fail. I'm shocked.
When I stopped Cyclespeed Tours, I bought Marine Control SL in Mallorca. We sell anodes for boats.Typically we use zinc for salt water, aluminium for brackish and magnesium for fresh.But none is used 'pure' and is a cocktail of other metals too
This happened to 2 of my Shimano DA-9000 cranks - brought back memories - the infernal creaking, the trying to source the issue (seat/frame), the mechanics having no idea - saying the creaking was coming from the spider bolts (utter-nonsense) even replaced an almost new press-fit BB to no avail. Eventually visible failure occurred, luckily non catastrophic. I ride in the tropics so I believe the moisture has an effect but a few friends have had similar issues with both Ultegra and Dura-ace cranks. Tried to buy Rotor but no stock so eventually found another DA-9000 (like rocking horse sh*t during a Pandemic) which will probably die after 20,000km like the last ones. Spoke to Shimano here in Indonesia.....Sorry Sir out of warranty. Annoying as my opinion is it is not fit for purpose - the crank spider /arm wears out before the chainrings!! I doubt however Shimano will recognise their issue - is 9200 the same construction? Its a shame as I love Shimano functionality and performance.
People who can afford to pay for this are top 0.1% rich. I don’t think most really care about this being a disposal part that fails under extreme conditions. I personally won’t care if this could fail since I don’t live in humid area and don’t ride like a pro at all time and all I care is that blink factor. For pros, all they care is weight and performance, durability has to sacrifice. It’s a trade off. That’s the logic behind that design.
Well done and very informative. So many bike companies and retailers refuse to stand behind their products, just expecting cyclists to replace "worn out" items because it is past the warranty period. One thing I will say about SRAM, I own some RED products and SRAM has usually replaced them past the warranty period.
A local friend had his Ultegra 6800 crank split, so add that to the list. Guess don't get your Shimano cranks wet and keep them in a humidity control room with your cigars haha
I think this has been you’re best video, informative and revealing…well done mate!
I like the way you use a washing up brush as a hammer.
It's an engineering slur.
Excellent analysis. High-end bike parts always push the limits between light weight and failure. Campagnolo cranks went from steel to aluminum alloy and then Super Record (1980s) got even lighter. Failures became commonplace in short time spans. Shimano 105 is a happy medium between performance and weight.
Abit of bad news for you- the rotor aldhu 24 uses a steel axle (the 30mm one uses an alloy axle) which is connected to the aluminium alloy crankarms (7075 or 6061 depending on whether its aldhu or vegast) by a threaded bolt (which I think is aluminium) so you're unlikely to run away entirely from galvanic corrosion here.
That being said, the entire crankarm is anodised and the rotor crankarms are a solid machined billet of aluminium, so any galvanic corrosion problems are unlikely to be catastrophic. The most you might have is a crank that might be hard to get out- but a thin layer of marine grease on the mating surfaces should solve the problem.
Yes, I noticed that from my 24mm Aldhu order coming in.
Nothing that a good lubing up won't solve 🤣
@@phil_d You are correct Sir, proper lubing is key to a successful outcome...🤔😉
There's always time for lube.
Now I finally understand why the aluminum inserts for by bottle cage screws are corroding so bad on my carbon Trek Remedy. It is literally rotting away and I can't do anything about it. Thanks my favorite 5 year old for the awesome explanation!
I think the sheer amount of bonded dura ace and ultegra cranks still in warranty put shimano off from acknowleging this, can you imagine the bill if they were expected to proactively replace every crank in the same way canyon, specialised etc have in recent months when they acknowledged engineering faults.
Had already decided Rotor would be my next crank, appeals to me anyway due to coming from a BMX background where 3 piece is the norm, just another good reason to go that route now!
My Ultegra crank cracked after year of normal use. Here in Lima, Peru. Shimano is replacing it, hope it lasts a little longer this time. Thanks for the video ¡
Thanks for the no-shite, serious engineering explanation of the problems that ill Shimano. It's not that they should know better - they already do. But they are ignoring potential disaster if they continue to keep their heads up their arses. This will not go away anytime soon.
It could end up like AllCity Cycles if they keep ignoring it.
They’ll start to give a shit when a crank gets delaminated in a big race. Imagine that happening in Flanders or the Tour … the PR disaster alone should make them care about it.
@@endcensorship874 You can bet that the cranks and other kit that Shimano sends to its sponsored teams get the pro peloton treatment at the factory before anything happens. Assume components such as the cranks are put through extra treatments, materials and assembly steps that the regular production trash never get. That and additional inspections and an insane QC rejection rate. Just assuming, of course. And wonder what special instructions the team mechanics receive, or are there factory-recommended service lives between replacements for certain components such as the cranks. And supposing that these practices by Shimano may be the case (because I'm just guessing), it would mean that somebody - or several people - knows what's really up with these things. And if people know, maybe somebody will talk. And if somebody talks, that would be very bad for Shimano.
@@RReese08 pros on big name race teams go through bikes and replacement parts like crazy. Failures are less likely if something is only a month old. Whereas it is not unreasonable for a consumer to keep a quality bike for many years and they aren’t having a pro mechanic going over the entire bike every day or 5 while being ridden by a heavier rider. A bike holding up for 2 months and parts replaced when only 10% worn by a 150lb/68kg rider with good technique isn’t nearly as impressive as being replaced at 50%-100% worn by a 260lb/120kg rider with poor technique.
@@stefhirsch6922 I agree.
OMG...That creaking noise was on my bike as well and I never figured out what it was until watching this video. I know it wasn't the bottom bracket because I had one of your bottom brackets installed. I then thought my frame was cracked somewhere but I couldn't find it. Long story short my bike was stolen so the issue went unsolved until now. Thank you for making this video.
Loss of face to admit failure is likely a contributing factor to S’s inaction - as a practising lawyer they are setting themselves up for a class action, not only for a defective product, but also a PI claim should your final premonition become a reality.
A little off topic but I had a number of crank arm failure years ago when riding top of the line forged Campy cranksets back in the 80'a. I had three separate failures on cranksets that were supposedly under warranty. The first time the local bike shop gave me a replacement crankset and send it back to Campy. The second time a year later the replacement failed and they replaced it again. The third time the shop would do nothing because they said Campy rejected the second one and they never got paid. When I said they were under warranty they told me to sue Campy because the shop was not taking another loss
None of those failed forged Campy cranksets had ever had a crash and were in nearly mint condition. They all failed under hard pressure either sprinting or climbing hills and caused crashes.
People need to realize when their cranksets are under pressure and fail (no matter what the brand or model) it is like stepping of a cliff and and you either instantly fall over or you stay up with a damaged arm pointing up with the good arm under pressure pointing down. In one of my failures the later happened and my shin turned in and the upward broken arm sheared right up my shin and cut me very badly and I had to tie a bandana around my leg to limit the bleeding. On top of all that I had to ride hope after all the crashes and injuries using just one good crank arm.
After the third failure I switched from Campy to Shimano Dura Ace and never went back and have it on multiple bikes although only three have Dura Ace 9000 components (the rest are older 10 speed series).
I have never had the Shimano failures described in this video but I did have a Shimano Dura Ace crankarm that I had a hairline crack through the pedal hole that I noticed before it failed and they replace that crankset under warranty but it took awhile to get it.
I would suggest that people regularly clean and inspect their bike components and frames (I have had some of them crack and fail as well) so they can catch problems before they become serious and cause failures out on the road. I learned the hard way.........................
Had this happen with my Ultegra, actually sent you a note about it. The fact that they for sure know it's happening, and haven't done anything about it yet, is just dumbfounding. Really interested in the new 12spd stuff and how that is going to hold up.
Makes a lot of sense. Had a pair of Oval Concept 950 alloy clincher aero wheels, original equipment on my Fuji Norcom Straight and wanted to centre them as the spokes also felt a bit too loose. When I started to adjust the tension I realised that no matter how hard I tightened some of them, no effect. Then I had a closer look and realized that more than half of the spoke holes inside the rims had cracks, most if them several millimeters long. In general, the overall, apparently not even anodized alu part of the wheels was covered in corrosion products very similar to the ones in the Shimano cranks. I always wondered whether it is good design that when cycling in the rain, water was getting into the rim and it gurgled around it in there until after about a week, it finally evaporated. Now I know what else it did in there than just making funny noise. Steel aero spokes in direct contact with aluminium in dirty water - guaranteed desaster. I was lucky that I found the cracks before the wheels collapsing while driving. So, contact corrosion seems to be a problem generally underestimated or ignored by component manufacturers.
This is your GREATEST ever video Mr Hambini-man!!! As a passionate and committed CAMPAGNOLO devotee - you can't imagine the absolute pleasure Shitmano's product failures are giving me! LOLOLOOLLOLOL!!!!
PS. Point of interest - whenever aluminium and steel come into contact, they create an extremely aggressive electric reaction - as you quite rightly stated, a kind of 'battery [Galvanic] effect'. This is also known as 'electrolytic corrosion' - which produces a whitish powder residue.
Electrolytic corrosion was very commonplace with automobiles [especially during the 1950's and 60's] when car manufacturers started using aluminium and steel body panels together. Indeed, it became such a problem that rubber beading had to be inserted between the surfaces of the two metals to prevent them coming into direct contact.
Unfortunately, the rubber beading would rot away after a few years and car owners would suddenly find entire areas where steel wings came into contact with aluminium bonnets and boot lids for example, totally corroded away.
Yeh, well you should see the 'reaming' he gave Campag too. My Shimano cranks have never failed, but then I'm not daft enough to lean my bike against a central heating radiator and not realise how harmful that is to bonded components be they hollowtech or carbon.
You're as stupid as the other fan boys.
@@mcspikesky Dentists can afford that
I bought a De Rosa Idol with Campagnolo Potenza, best bike I ever owned with the worst groupset I ever owned, an absolute pile of shit - Within 500 miles the right shifter snapped and the bottom bracket sounded like a ratchet with all the clicking noises it was making. I've no idea why Campy insist Potenza is comparable with Ultegra, it simply isn't... maybe Claris or Sora but no higher. ChainReaction couldn't resolve the problem and wouldn't swap the groupset to Ultegra so I ended up with a refund :( Shame as ignoring how crap Potenza was the bike was beautiful to ride and the thumb shifters I absolutely loved
@@mcspikesky ......Mmm - I admit that I am a half-wit. But that makes me twice as clever as you.
bought a 105 because of this and its still going strong. also using steel bearing BB also due to what I learned here. my previous ceramic bb spoiled at 100km.
Shimano has officially recall their Ultegra/Dura Ace chainsets 2nd gen batch due to bonding issues. 105 is unaffected.
Hambini, go for Hope’s 30mm all aluminium road crankset! I have fantastic experience in last two years. Very well made but pricey. I personally had issues with modern Rotor crank (it was Vegast crank model with 30mm alu spindle). It was creaking a lot from the start, which I thought had to do with DS side spindle spline tolerances, which caused creaking in the spider/ring (one piece) interface. It drove me mad and could not get it to work.
Mine failed on winter bike on Saturday, Ultegra R8000
Been well aware of the issue so check the crank/chainring for gaps while cleaning the drivetrain after every long ride. Went without warning just a pop/clunk while out of the saddle. Starting to separate in the centre and a crack forming on the crank arm behind the small chainring😠
Fortunately didn’t totally fail as still had 40+ miles to get home
The recall has been announced 760k cranksets. Awaiting the childish followup video.
thanks for the informative video. I think I'll keep my older 105 crankset for a few more years.
Instead of talking crap, as i mostly do here,
I will give some background to your comments;
Did a vid on this and the short answer is, Shimano is not admiting this problem exists ( as a design problem).
As to the corrosion, they is a number of issues there. It is not just about steel and aluminium, but if you have big swings in temperature, the dew point changes. This means you could have a partially saturated air in the crank at manufacturering. But when the temperature changes the moisture becomes free in air and the cycle of corrosion starts, making an electrolyte for the corrosion. Starting the process, although it maybe fully sealed.
As to fail safe. The key is the unwanted outcome, i.e. you have a domestic charger pack with a transformer in it. The unwanted outcome could be that it catches fire 🔥. If the tranformer failures, and it either doesn't catch fire or cause the plastic surrounding it to catch fire. It is deemed to fail safe. These tests are pretty general for domestic products in western countries and these tests are defined by Mandatory Standards.
10:04
If the hidden endcap is not an integral part of the spindle and merely assembled on, then it shouldn't be bonded.
micro-movement induced by pedaling torque may form opening/crevice at this endcap and resulting moisture ingress.
Or, alternatively, there's pre-existing gaps at the joints between steel spindle and forged base spider.
Guess it kinda shows how bad cycling industry is with admitting fault, even Japan. Hell at the moment with the Toyota Yaris Cross there's a recall for all vehicles happening because one person hit a bump too hard, hit the inner wheel arch lining and it fell off.
Glad this video is up. My bike came with full 105 group set but not the cranks. Wanted ultegra but got 105 because the weight difference is sub 100g and stainless steel chainrings. But here is another reason to use 105 over higher end stuff
16:55 Just a small point. You are conflating "Factor of Safety" with "Fail Safe". Factor of safety is the amount of excess load a component can bear compared with its expected maximum loading in normal use. For example a SWL 10 ton rating lifting component (e.g. shackle) might have an actual failure rating in excess of 40 tons. This is called the safety factor.
"Fail Safe" means that a component or system is designed such that in the event of a failure the component or mechanism does not represent a danger to users or other components in the system. An example of this would be a runflat tyre which is designed to stay in place on the rim in the event of a puncture or blowout.
An example of "Fail Unsafe" - (fail dangerous?) is the RCD (Residual Current Device) on modern (UK) domestic circuits which protect people against electric shocks. There is no indication of a failure condition (which is why they are supposed to be tested regularly) and in the failed condition power is still passing through them with no shock protection.
"I got the same power output of a fucking shrimp and i manage to break mine" LMAO
Well done. The (few) carbon frames I’ve built all used alu inserts for headtube and BB. This allows for traditional bike shop tools to ream, face, and in the case of BB chase threads. These frames have all been equipped for standard BSA bottom brackets, which of course allows for external threaded bearing systems as well.
Due to galvanic concerns, the alu bits are first wrapped with epoxy fiberglass as an insulator. I have no doubt that over time, particularly at the ends/faces, there is the possibility for galvanic corrosion. And eventually, this will likely be the primary cause for the frames ultimate failure. While I anticipate this to take some time, I don’t expect a CF frame to last as long as a typical steel frame.
Now the methods noted above will not lead to record light weight frames. But I think light weight is way over rated. Especially because UCI weight minimums mean that record light frames aren’t necessary to hit UCI requirements.
But, the fact is that the various concerns re CF and weight obsessiveness has lead me back to traditional steel frames.
Steel is good and aluminum is also good enough for my riding. I figured that galvanic corrosion would be the downfall on most carbon or bonded aluminum.
@@Drago0900 there’s no possibility of galvanic corrosion between carbon and a metal.
@@nstrug there actually is. My aluminium bottom bracket sleeve got loose in a carbon frame because of galvanic corrosion.
@@MartijnPeek I’m confused as to how that could happen. Don’t ions from both the anode (Al) and cathode (C) have to be soluable for the reaction to occur? I guess the carbon could act as a conductor to steel parts such as rivnuts which would then set up a galvanic circuit.
@@nstrug yep, carbon is conductive so that’s all it takes I guess
How well has this aged? Like a fine wine. Oh Shimano.
Luckily I wasn't sucked in by "lighter is better" with Ultegra or Dura Ace, and I went with 105.
With that said, I worked as a crew on some Sportfishing boats in Hawaii, when we took the boats out of the water to redo the bottom, we also had to replace "the zincs" on the stainless steel shafts and rudders. I wasn't initially aware of the reason what they were or why they were on there, but was told by one of the captains that they are on there because of the electrolysis, and that they are designed to corrode instead of the steel (and aluminum in other places).
In light of that, I wonder if it would be wise, or even possible to connect a small piece of zinc on area of the bike where 2 different metals are touching to prevent the corrosion of the softer one (usually aluminum).
It is called cathodic protection, all big ships and buildings have it.
Sydney opera use the same stuff.
Yes but it would add weight which isnt what is being marketed, its lightest crankset possible or nothing
@@coreygolphenee9633 My 105 set on the bike in my profile pic still works. The funny thing is that my TT bike weighs about 8.5kg and the bike in my profile pic weighs about 13kg. It takes me 230w on my TT bike to do 37.2kph and it takes me 194w to do 38kph on the bike in my profile pic. That is 36 watts difference. When I put 230w on my recumbent bike I am doing well over 40kph.
All the DF riders talk about 100g here, or 200g there, internal cabling, waxing their chains instead of use any type of oil. But as soon as you tell them to move the parts around on their bikes to make it way more aero they get all weird. The UCI banned recumbents because they were too fast.
I say "Fuck the UCI" ;)
@@casualguy393 I ride track bikes mostly and ill just that the hittori hangout NJS dura ace cranks, its my favorite part about track bikes is that if shell out dough for the nice stuff the components are ludicrously tough
Aside from the no stopping it, lending to the failure is also the quality of the metal and impurities speeds it along
So if you are looking at a Titanium bike frame, you really need to use carbon finishing kit to make sure it doesn't react as they are both fairly unreactive?
correct.
Exactly what I have.
If you are worried about the contact between the Al bearings and Ti frame (don't know what other contact point there would be) just use a copper or silver based anti-slip on the threads. This was what my manufacturer (Serotta) advised.
@@massspike My friends front mech clamp failed on his Ti frame. A carbon clamp with a braze on style mech would avoid that problem. I think the sweat+Ti+Al+steel bolt caused the failure.
@@MellowYellowCJ7 Aaah...I ditched my front mech years ago so wasn't thinking about that failure point
I can vouch for you hambini, when he's explained the cathodic protection in maritime industry I know he knows what he's talking about👍👍
I've seen this problem a lot. I been thinking 🤔 lol wonder how accurate the power meter is while the front of the crank is twisting. But the twist is more from the failure causing false read outs....
Didn't anyone tell you never to go for XTR or Dura Ace? The advantages for amateurs in non existent and the disadvantages are massive. Great analysis by the way. Gives me lots af ammunition to give my Dura Ace friends a hard time.
I have the DuraAce 9100 crank so I'm a little worried about this happening to me. I also work in US aerospace. We commonly use stainless screws, washers, threaded inserts in combination with aluminum alloys (6061, 7075, 7050, etc). To minimize the chance of galvanic corrosion we apply primer between the faying surfaces to seal the joint. I'm surprised that Shimano didn't do the same thing between the axle and the crank hub. I would think that water would have to get in there to start the corrosion. How? I don't know.
I just love my easton crankset all the more. Such well thought engineering.
This was very well done Hambini, (minimum of cursing); took me back to engineering meeting days.
It's very likely the Japanese engineer(s) that created this fiasco had to shave their heads in disgrace.
Amazingly though I did not hear you mention sweat as it can be one of the better electrolytes.
And everybody sweats; granted some more than others... so even in a hot dry climate the presence of electrolyte is likely.
Agree that shitmano should be recalling those crank sets.
Brilliant video Hambini. Thanks 😁👍
I think that Shimano lost their way a bit after the 7800 series (which, personally, I still think is the most asthetically pleasing groupset they ever made) which seemed to be well designed and made from an engineering standpoint. Gluing carbon fibre together in this way is asking for trouble when exposed to thermal cycling and exposure to road borne contaminants (oil, salt, water etc.)
Yeah. 7800 5 arm looks like a real crankset. When they went to 4 arms and hid the bolts it was a backward step.
Look at how dirty that crank is; it must be very nasty where these cranks are used. Thank you for the video.
Not a fan of threaded BB personally. I just lost another frame, nice carbon bike from 2014 with a disbonded BB shell. BB386evo is such a nice combination of features, and it'll never have a shell disbonding failure :)
Unless it's an alu sleeve in there.
Jokes aside, gutted for your loss. Threaded is good for maintenance but it may not be good for carbon since torquing up your bb may put stress on the alu insert and damage the bond(don't quote me I'm not a mechanical engineering undergrad, I'm a hospitality management undergrad lol) I only torque up my bb to 12-17nm and I've never had problems in 3-4 years.
@@dan_lazaro the aluminium sleeve is the problem, eventually all inserts will fail. (I've also never overtorqued the BB as it self tightens anyway).
I disagree that threaded is better for maintenance, it's much easier to extract the bearing in a pressfit BB than to extract the bearing from a threaded cup, just eliminate the middle peice.
I’ve actually just had the BB shell replaced on my Time VXRS, wasn’t that an option for your bike?
@@MartijnPeek I took it to the carbon repair place here and yes it would be possible but more than the frame is worth.
Given its rim brake, no point repairing it.
@@galenkehler ah okay, was it a cheap carbon frame?
What would be nice is to dig a bit deeper into Shimano's line of cranks and see if GRX groupsets are also affected. They look more like 105s but might as well make the PSA complete.
Have you had any reports of these failures on the latest dura-ace cranks released last year?
I'm not sure if Shimano have revised their crank design and bonding process to address the issue or continue to produce more of the same.
(The latest cranks are slightly heavier than the previous generation).
I continue to use the earlier Hollowtech 2 generation cranks which are presumably welded/forged? Certainly there is no visual joints.
I think that the later 105 cranks also have the bonded /cast design and presumably fail in the same way so going to 105 may not be the answer unless they are the older hollowtech 2.
Shimano stuff is usually very good and hopefully they will eventually come up with cranks which do not break up, Until then I will stick to the older heavier Hollowtech versions.
The new 9200 DA crank is quite a bit heavier than before, so presumably they just beefed it up. But there are many lighter, better cranks out there than this supposedly 'flagship' model that costs a fortune.
Spot on. Thought it was a creaking BB, turned out to be the crankarm. First it was Ultegra, I moved to a DA but suffered the same fate. 2 crankarm failures in less than 3 years.
Great video, been waiting for this one to come out, does look like a design failure, wonder why they didn't dip the steel axle with coating to prevent the galvanic process between the steel and aluminium interface. I use Campagnolo cranks which seem to last forever, super record axle is titanium. Shame as I like the look of the Dura Ace crank but I'll be sticking to the Campag.
It has nothing to do with the construction itself. I have 105 crank sets which have thousands of miles on them featuring aluminum bodies and steel shafts. And I ride in Switzerland in the winter where the roads get treated with salt -> perfect electrolyte. So there must be something shimano effed up in the construction of the failing crank sets. My bet would be moisture creeping in somewhere and the oxides splitting the stuff open and loosening the bond. Bad anti corrosion concept. Finally the battery accelerates it for the "final sprint".
@@cls9474 "It has nothing to do with the construction itself" "So there must be something shimano effed up in the construction of the failing crank sets" Not sure I understand your point as it seems to contradict itself. Do you mean there is nothing wrong with using a steel axle with aluminium crank spider? True if there is something to prevent moisture between the two parts but a bike sits outside and atmospheric conditions will cause moisture on the inside of the crank arms. If Shimano used a barrier layer between steel and aluminium that would help. I believe 105 cranks are made differently to Ultegra and Dura Ace.
@@danbanham728 No, it doesn't contradict itself. The only difference is that the 105 are welded (no seam where moisture can creep into). Apart from that the construction is the same. Riveted steel axle on an aluminum body. And as I said: I don't know anyone in my bike infested circles who had any problems with the 105ers. I have a bike which I just maintained (just installed the 4th BB) with a triple 105 and same construction: Not the slightest issue. And I ride in the winter in the mountains with salty snow slush. For more than a decade.
@@cls9474 Ok, so the construction isn't the same then, one is welded and one is bonded.
@@danbanham728 Yep, but the battery exists on both. And that's what I'm talking about. The steel-aluminum design doesn't seem to be the problem as it seems to be managable. And that's your main point in your original comment.
Tip my hat. Excellent documentation and explanation of the subject. Engineering over marketing any day.
GRX cranks, still Hollowtech (but hollow forged) I assume would be just fine as well, albeit the weight penalty.
I'm using GRX because supply is shit and they aren't too much heavier.
They’re still bonded and thus able to fail in the same way.
@@stefhirsch6922 My GRX cranks are hollow forged.
@@biamarconchi I just ordered the RX810 for my bike build. How is it different from the failed crankset? Thx!
Crazy ass gunshot wound reveal. You are the best thing to happen to the internet.
Was that gun shot wound from a previous Hairdresser?
not quite! wrong place wrong time.
@@Hambini got caught nobbing Belinda with the big bazookas
Marine sacrificial anodes are generally zinc blocks, which are replaced on a fairly regular basis. They only work if any metal required to be protected, is in electrical contact with the anode.
Great vid I'd like to hear some pro road mechanic's feedback, I'm sure they've been dealing with it for years, Shimano in all their glory will say they've addressed the problem with their new 9200 series groupset and I'm sure mixing the metals and the corrosion will continue. I choose Rotor cranksets, 30mm axel and I love the modularity and just the superior machining and engineering.
just bought a Rotor set myself as a replacement for shimnao
Zinc anodes are what's normally used in boats. I've pop riveted (usually monel) many 316 stainless fittings to aluminium masts. I always provided a barrier between the steel and the aluminium. Plastic packaging tape, the really thin stuff about 50mm wide, seemed to do the job.
Although I have switched from my 6800 with sigeyi power meter to Aldhu 24, this is exactly what I'm waiting for.
BTW, I found a lot of Chinese "CNC" cranks (dirty cheap, less 100 yankee dollars) with 24 mm axles (some thick 7075T6, some steel), all with SRAM 3 pin direct mount.
Different preloading methods (from direct shimano copy to SRAM/Aldhu like preload ring).
Some good ones (like the one from Fovno) weight only 515g (cranks + axle), only slightly heavier than aldhu 24.
Any intention to review some of them?
I have the Fovno Phantom and the most common issue is there M14 bolt breaking. Also, there's no available M14 bolt replacement to buy anywhere. Other than that, everything's really well done.
@@WashichawbachaW Awesome!
They can fail miseraibly:
th-cam.com/video/2SMUFxFL1bU/w-d-xo.html
I think you just explained the creak in my TCR that I was never able to find which ultimately had me selling it and buying a Super-Six Evo. (yes, Hi-Mod, of course)
Simply disgusting.
Great job Hambini, always direct and serious explaining
There's an old bike shop mechanic saying and I have heard it more than once over the years " Shimano wares out and Campagnolo wares in "
The conclusion to get a 105 really put my mind at ease, because (being a rider on the lower end of mediocrity) I could never justify spending more than 2k on a bike, so now 105 is what I have on both of them 😂
105 was my workhorse for my first 20 years on the bike. I fell for Dura Ace 7800, the last of the silver. 105 is still really, really, good. I have Ultegra DI-2 now but did not fork out for the cranks and kept my 105's. Happy days
I am very knowlegeable in material sciences. This video was very thoughtful. Everything explained is correct or on the right track of thinking.