Thanks for these Shimano comparisons! These details are so important. The headache of ordering the wrong part is maddening. Bike shops don't always have the most informed staff these days. So you have to know what you want.
I’m trying to run 49mm chain line cranks on a 52mm frame/wheel set and a 3mm offset chainring. Not having any luck very noisy drivetrain. Any ideas? 6mm offset chainring ?
@@LoveMTB In the taller 2 or 3 gears chain must be rubbing on cassette because of the sever angle in the alignment of the cassette vs chainring. I'm running boost wheel set and trying a 140mm length cranks that are meant for non boost, 49mm chainline. Any ideas as what to try next? Current chainring has a 3mm off set.
Hi i tried ti install a deore 6100 crankset on my 2019 specialized chisel but found out that the deore 6100 spindle length is short for my frame, would the deore 6120 spindle length be enough or do i need to get the deore 6130, hope you could help me out.thanks
Thank you for all the useful info. I just order a 8120 crankset and I thought I made a mistake. After watching your video and check the Shimano website manual, I can confidently install the crank. It’s amazing that you included every detail we need, even the spacer direction! Thank you
This channel is the best, you always cover all the details I wonder about that no one else seems to cover. I recently purchased the M7100 crankset for my boost frame and was confused between if I should get the M7120 or not. It was confusing that both were listed for boost frames. With the 7100 the 32 tooth is pretty close on my frame but is still good enough to run like that, but for now I’m running a 30T Oneup as my cassette is only 42T. I’m in the easiest 2-3 gears for a lot of my slow technical riding so glad I ended up with the 52mm chainline. Not being able to run an oval or 34T isn’t a big deal for me but this video is very helpful to help people decide between the options.
Perfect video at the perfect time for me. I ordered the XT8120 and then realized the chainline difference of 55 than 52 from the 8100. This video has explained what I needed to know and has eased my mind. I'll be installing it this weekend hopefully.
When dealing with so many standards for components it's easy to get discombobulated and confuzzled. But you my friend are so thorough, and I mean thorough. I come back and realize new things that I missed months ago. Thank you man seriously 🙏🙏🙏
Great video! My experience with the new Shimano cranks is that they are providing three sizes for quite a few scenarios and, in many cases, the chain lines are not ideal and often push the chain outboard. If you're riding areas are slow and techy and you spend a lot of time in the bigger cogs, it's lousy! There's options to fine tune this though. For threaded bottom brackets you can buy a bag of varying width spacers which would allow you to move the chain line a couple millimeters. You can also change out those 3 MM shimano spacers with some wheel manufacturing spacers and stack a different amount on either side to fine tune (e.g. 1mm on one side and 5mm on the other). Both my bikes put the front chain ring dead center on the cassette.
Curious, do you notice the difference between the spacings in your knees, or pedaling? I like this option, but curious about the spacing not being even. Thanks.
Your video helped me so much, I got a Shimano SLX M7120 crankset & BB installed by my local bike shop and I was doing a mid season cleanup and re-lube when I removed the crankset and both spacers were installed on the drive side, it just didn’t look right I was confused because the spacers didn’t seem to be built to be placed together, after watching your video everything started to make sense, I immediately looked it up in the Shimano manual for some redundancy and was able to confirm it! I guess some local bike shops cannot be trusted, thanks so much!
I love the Shimano rear mechs but I almost always pair with a Sram crankset. My thought on chainline these days is generally to get the chainring as much inward as possible.
Question - since the 26 wheels are smaller have you considered going for the 1x11 GS derailleur and 11-46 cassette? It fits a lot better than the 12 speed. Just a thought
@@LoveMTB Answer: Yes and thanks for asking. Here's complete analysis and my requisite flow chart for Circa 92' Univega w/ unique AMP parallelogram fork: 1) XTR Thumbshifter a must 2) Tubeless, conversion? If possible would go along way to keeping me on my existing wheel set and hub. Cane Creek straight pull and they've been great. 3) Wide range is a must. I pull a BOB trailer at times inclusive of ball end skewer. 4) End result- An ugly sleeper/Townie/Adventure/ Do whatever ride I can chain lock to a pole and still come back to it. 5) Very much considering XTR 1x simply to keep wheel set, even if I have to stick with tubes. In a perfect world I'd stick with XTR 2x on my existing wheel set converted to tubeless however, the writing is on the wall and all this is moot if product is unsupported into the future; hence urge towards 1x12. End game simply: to not leave another frame to the landfill. Repurpose, reuse, refuse disposable culture. Provide work to men in a shop not corporations and offshore manufacture. It's rather personal to me. We start the build in the next couple of weeks. Any advice would be much appreciated. Thank you. You've got a wonderful channel!
Well I'm running 2x11 on my 2010 stumpy with the deore 48.8mm chainline nonboost crankset very smooth shifting. Thanks for this video, I feel like I understand q factor and chainline much better now.
I did suspect chain line falls onto smaller part of the cassette always. Also on mine mixed groupset hack. Despite 10sp cassette is narrower, but that width comes from left side not going into spokes as much. So 1st gear chainline is benefiting the most, plus derailleur gets more spoke distance, which makes the derailleur much less stressed out not having to work so close to spokes 😋
Hi there, I had a problem trying to fit oval chainrings to my bike. Most aftermarket ovals have offset which varies depending on type of crank. I found out from the my bike's frame model(boost) is made for 52mm chainline...The bike comes with deore m5100 crankset 32t (11speed) which is has a 52mm chainline. This particular crankset can be used on non boost and boost frames. Same goes for the shimano crankset lineup 52mm chainline m6100/m7100/m8100.(The m6120/m7120/m8120 are 55mm chainline)...However when used on a boost frame like mine. It will give you a very tight clearance especially if u go up to 34t or an oval aftermarket..I would not be surprised if the oval can't fit even with 30t ones because most ovals have offsets bringing the chainring closer to the frame. I had to find a solution if i ever want to get a chance to use aftermarket oval chainrings on my bike. Adding spacers to the drive side of the bb to bring out the crank doesn't cut it... This is because you are shifting the crank outboard and it will be a problem to install the left non drive side crank arm. There is not enough to grab onto the spindle and it will not be safe. I know from experience coz mine flew off 😵💫 when I did this.This is for shimano cranks as the installation of the crank is different from other brands.I know I had to get a crankset with a longer spindle to accomadate the offset that comes with an oval chainring.. My solution was to purchase the m6120 (12 speed) with a 55mm chainline..next was the oval chainring from Garbaruk in 32t. The chainring model I purchased states it for m7100 series and the 8100series crankset. However, as long its for the direct mount shimano chainrings it would fit across all models with the exception of the M9100 series(XTR)...I think its because the xtr direct mount requires a different lock ring for the chainring(internal).This oval chainring from Garbaruk has an offset of 3.3mm. My bike ideal chainline according to the manufacturer is 52mm. So, 55mm (crankset chainline) - 3.3mm (oval chainring offset) gives me a 51.7mm chainline which is very close to what I was aiming for. My conclusion, if your frame is boost 148mm. Get the 55mm chainline cranks. This enables you to shop around for an aftermarket chainring be it for round or oval ,from different brands and choose an offset and how large a chainring that can fit ,that is ideal for your frame. Do take note some chainrings brands for 12 speed shimano needs to be used with the shimano 12 speed hg+ chain only...I chose Garbaruk coz their chainrings are compatible with all speed (9 and above) chains no matter the brand..check their website. If your frame (boost) chainline is 52mm and you get the 52mm chainline shimano crankset, you are limited to probably a round chainring with max of 34t depending on your frame clearance.Also the chainrings must have zero offset because with an offset the chainline will be lesser than 52mm.Unless your frame is meant for maybe a 49mm chainline? Just sharing my experience so to help others who are in dilemma of finding the right cranks to fit their bikes.
Thanks so much for this - I'm in a similar situation and trying to figure out how to make my chainline work with clearance for an oval chainring. I'll be ordering a Garbaruk chain ring it seems!
I think it's funny that Shimano finally went direct mount but chose to produce two piece units with a spider attached to the chainring. Aftermarket options look so much cleaner!
@@mtbboy1993 Same here. I also went down to 170mm cranks which helped. We have a manufacturers in the UK called Superstar Components and Uberbike who provide high quality chainrings at much lower prices than Absolute Black. I must have 5-6 of various shapes and sizes lying around.
@@benmillns8976 getting those will cost same as the Absolute black probably due to added value tax of 25% and shipping cost to 🇳🇴. So I get absolute black. I've not tried superstar components. Absolute black is sold in Norway, its easy to get, I got lucky to get one second hand for good price, even got Renthal Apex stem secondhand. 👌
For Shimano 12 speed and non-boost frames, Garbaruk is the best option because they propose chainrings with excellent chain lines and ovals. Great video, as always 👍
Man, you always hit every single aspect and spec of whatever it is you're reviewing.... always so good. I was a devout Shimano crankset user myself before my Chameleon came with a SRAM DUB crankset, and I'm now a Kool-Aid drinking DUB disciple. I love their BB and the overall design of the cranks, as well as the simple offset in the chainring that allows my cranks to move between bikes with only a new chainring. As for that chain line on all of our 12speed transmissions...... yikes! Come on gearboxes and get here already.
Your level of good information is quite simply the best around ! Every time you put out a video I learn something and I consider myself fairly knowledgeable. I'm struggling with chain line on my '16 Trek Fuel EX8 and buying a new crank soon. Settled in on a Race Face Turbine so I'm hoping there will be enough adjustment to correct mine as well. Keep your channel rolling.. it's quite good and very helpful.
Did you buy the race face set yet? I am in the same market. I have a goofy boost 141 (148. W/qr) so I need the 55mm chain line. I’m interested to know how to achieve this with Race Face products
Thank you so much for this video. I Blindly ordered a M6100 to upgrade from 1x10, to 1x12. Luckily my 148 boost frame has an aggressively indented chainstay at the crank. I measured the shaft on the old crank and it was 115mm just like the M7100. Thank goodness!
i decided to go with 55mm chainline as the Q-factor is same with my older crank M5100. Not liking the 55mm offset, but I need the chainstay clearance for my crank boots.
Wow. I've learnt so much from your videos, and I haven't even have a bike yet. I'm still shopping for parts and you sir helped me a lot on what to get and what to avoid. With everything I learned so far, I'm pretty confident that my first mtb build will be enjoyable and should last me a long time before needing an upgrade. Thanks!
Thank you so much for the info!!!! I recently bought a rocky mountain growler 50. I decided to go with an oval chain ring system from one up components only to find out that the deore cranks don't support direct mount spiders / chain rings. I have been racking my brain with all the new superboost vs boost and so on. I found a set of slx cranks that support direct mount of the oneup system and this vid actually clarifies nearly a week of research I have done. thank you again!
Hi, nice to meet you here again after that “strange blackout”. I wanted to share with you an trouble that is really becoming a bother to me. My mountain bike is old enough for having a non-boost frame and so unique to have a PF30 bb shell 68mm wide (and 46mm diameter). so when I upgraded to twelve speed I bought a brand new GARBARuk 6.4mm offset chainring with my new M8100 crankset. Long time before I changed the former Shimano bottom bracket with a Token Fusion PF30PS one. This time I took my bike to my mechanic to mount the chainring and the crankset. So I didn’t notice anything special. But lately I went further with my bottom bracket looking for a noiseless bike and changed that Token bb with a custom mix of clean PF30 rollers (a minimal cup with the 30mm inner diameter roller) and I kept the old Token PF30 to 24mm adaptor. So when I put the left crank arm I noticed that it didn’t fit to the axle even with no washer. So I took measures and I got a bit disturbed. this is what I got comparing M-8000 vs M-8100 crankset. th-cam.com/video/NEWraGuNGrM/w-d-xo.html
I was recently looking at upgrading my older RF Turbine crank to Next R and had a look at the RF Q-factor Chainline guide. They have 148 boost paired with a 52mm chainline which is quite a difference from Shimano's 55mm. Also, doing my own measurement, 52mm places the chain in a straight line from the crank to the middle cogs of the cassette on a boost frame. Haven't seen any other sources indicate 55mm for boost and I saw in your video that the angle of the chainline to the largest cog gets fairly extreme with the 7120 (55mm) crank.
I am using 11 speed with 52mm chainline boost I just installed a new GX 170mm crank from my old NX 175mm crank and I love the new one no problems! Cheers!
You get a like yes or yes. I have been doing this investigation about chainline on 12s drivetrains for ages, and there are no other videos out there expalining this as good as you do. I am waiting for my 2x10 to die (142mm) to upgrade to 1x12 and have always been worried about not having options for a 49mm chainline. I now see 52mm should do OKish with my setup. hoppefully I can install a 34 teeth chainring at the front and not hit the chainstain.. Thanks, very educational videos that address everyday bikers concerns.
I am using 52mm on my 135mm bike for 1x12 XT with no problem... dont be afraid of it ... 51 cassette is little bit extreme but I try not to use it so often ...
Good info. I think that you just explained why garbaruk offers a custom offset. The standard offset is 3.3mm and the custom is 6.4, Seems like it is intended to give [6,7,8,9]120 owners and option for are narrower chainline.
That makes no sense. The 7120 is the wider of the two cranksets shimano recomends for a boost frame with a 55mm chainline. If you add an additional 3mm spacer on the drive side you are making the chainline 58mm which is more than Shimano's recommended chainline for a super-boost frame.
I'm considering doing something similiar. I'm not happy with the chainline on my kona unit x with boost wheels and m8120 crank. have one 3mm spacer on each side as specified but it makes the low gears run like crap. Since its a bikepacking build im going to be in that low gear a lot.
Thanks for doing this video, building up a new frame and you've just helped with my last problem, which chainline. Good to also know that the tool only comes with the full crankset.
It’s so easy to order the wrong part these days thank you for your videos I just ordered a 175 crankset luckily I got the right part 🤩 M9100 xtr I was confused because the non-drive side arm reads 9100/9120 But the Drive side only reads 9100 it’s perfect now I can hammer my new longer arms
Okay, so if I am using a non-boost frame and a 12 speed 1x, then the chainline shouldn't depend on the cassette. It should always be 52mm, right? I usually align with no. 6 cog from the smallest. Is that why I get a slow down-shift from the largest?
I have a Ritchey Ultra frame with 148 mm boost spacing and based on the Ritchey website, the chainline for this frame is 52 mm. I am running XT 8100 cranks and everything seems to run fine.
Running m7100 (52mm) with 32t round on a Yeti arc, wondered why the clearance is tight AF. This is an extremely useful video. I'm going to keep running as I am for now, especially since I get a better chainline in a hilly area, but it is super tight! No way could I go oval or 34t. Great video, thanks!
During my Chameleon build, I was pulling my hair out trying to fit a Shimano crankset, especially since I plan on running the bike with a short 415 chainstay (they are adjustable up to 430). I wish you had released this video a month ago - a great summary of the current Shimano crankset offerings. You would have saved my several hours of research. HA! My Chameleon, like your Yeti needs cranks with a Q factor larger than 172 mm for clearance. However I really need to run a chainline as close to 52 mm as possible or my dang chain will drop off at the slightest back crank. So the Shimano cranks were a no go for me. There is a reason these bikes come spec'ed with Sram cranks and I wish Shimano would figure this out. I bought Raceface cranks instead.
@@LoveMTB Yes RF does have varying spindle lengths. I have the Aeffect R cranks on order with a 137 spindle, 175 Q factor and 51 mm chainline. No rides on the bike yet, still waiting for the fork to come in. :-(
Super informative as always. I originally installed the XT FC-M8120 with 55mm chainline crank on my BOOST frame, but found the chainline a bit to extreme and my chain was actually dropping when backpedaling on the largest two cogs. Replaced the crank with the XT FC-M8100 with 52mm chainline, which the frame still had tons of clearance for and now everything is great. The chain stays on my frame are 420mm.
The same thing happened to me. My bike came with an XT M8120 and I exchanged it for an XT M8100. At the moment I have a 32 tooth plate. When I go to mount the 34 I will see if I have space, if not, I will mount the XT M8120 again. It is an Orbea Oiz M10.
@@LoveMTB Because you made a purchasing error :) I have mine set-up the correct way with 73mm bb and it seems larger than 55m chainline so need to put both specers on the non drive side.
WHY? WHY? WHY does Shimano recommend 52mm chain line for 135/142 frames? I spaced my M5100 crankset chainring (96 bcd) from 52mm back to 47.5mm by using 4.5mm worth of spacers and longer 16mm chainring bolts. Wish I didn't have to do that. Wish Shimano made a 1x crankset with 48mm chain line for their newer drivetrains. I'm loving the Deore M5100 drivetrain, just wished they made a crankset with 48mm chain line. My chain stays are only 425mm so 52mm chain line angle was too extreme. I do a lot of climbing in 51T cog. My drivetrain works perfectly, but only because I reduced my chain line to 47.5mm. No problem backpedaling on 51T cog.
@@noellereypelayo551 I placed nylon spacers between the chainring and the crankarm in order to move the chainring closer to the frame in order to reduce my chain line from 52mm to 47.5. I had to purchase longer chainring bolts. Went from 12mm to 16mm long bolts.
I had the M8120 on my 2020 Trek Fuel EX 9.8, but once I built my 2021 Banshee Paradox with the same crankset it caused terrible back pedaling (would come off top 3 cogs), I had to find a small chainline crankset. I got an M7100, which funny enough was lighter by 70 grams than the M8120 because of the shorter spindle.
Technically, crank manufacturers should make chainrings or crankarms to adopt every single O.L.D., I decide to use MT510 crankset on my 135mm QR old bike but its 52mm chain line is obviously optimized for 148mm rear axle.
Thanks for the Vid. Good stuff as usual. On my Sb150 I ended up put the spacer on the NDS side to get a better chainline, and it eliminated drops on backpedal on largest cog.
@@LoveMTB I'm loving it so far but I haven't tried it on real proper rough trails other than one weekend, so I look forward to putting some time on it this season. I just ordered a Mara Pro as I am not completely happy with the X2. Normal days I ride a smaller 120mm bike. Will you be making a review and bike check on your steeds at some point? Since you do spend some time tinkering and thinking about specs I think it could be interesting. Also if you do your own suspension service, it could also be great content if you do full rebuilds!
Also got an SB-150 and about to fit a new 8100 crank, any idea what the part number for that spacer is, just ordered Y0JC61000 but its just a paper thin sticker, not a 3mm plastic ring like in the video
Great and very informative video! I see from your other SLX review video that you have a 2018 giant trance 3 - it's a boost bike with stock cranks (FC-M7100-B) that have a 3 mm offset and 172 Q factor - if I'm going to upgrade to SLX 1x12 should I be getting the FC-7100 that better matches the stock config? I'm worried that the FC-7120 with 55 mm chainline would be problematic with the 51t as you mentioned.
I used the M6120 on my boost frame. Chainline was way too outward when using the larger cogs. I think it varies with bike to bike. Does not mean M6100/7100/8100 is definitely for non boost or that M6120/7120/8120 is for boost etc. I also contacted Transition about this and they actually recommended the M6100/7100/8100 on their bikes though they are boosted frame. So best is to check with the bike manufacturer.
To fix that chain line grab this spacer kit: www.amazon.com/gp/product/B07N4CSRS8/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1 Just make sure the total spacers equal whatever Shimano gives you.
I wish I knew this before I ordered 7100 for my boost mtb frame. If I add any spacers the safety clip does not clear the hole on the non drive side of the crank shaft as it does not stick out enough. My workaround is no spacers.
Great video. This helped me resolve an issue I was having on my Chromag Rootdown. I was looking at installing an older M780 Crank but the spindle isn't long enough. Shimano specify Qfactor but not the actual spindle length. Looks like I need an 8120.
Dumb question... when a chainring offers 3mm offset, is that outward or inward? Assuming outward? So if I added a 3mm offset chainring to the SLX M7100-1 it would give me a 55mm chainline?
Great Video great explanation, althought sram groupset on my bike. Installed my 55mm cranks even though my bike has a 52mm chainline and I have to say everything works great. You are doing a great job my friend. Thank you 👍🏻😀
Hello dear, could you help me with a question, my boost 148 frames are for 27'5 plus 2.8 wheels, the most recommended cranks are 7120 Qfactor 178? Does 7120 work for chain line 52 and 55 or only 55? thanks
How do I know in advance, which crank length I need? I doesn't look something that is accurately measurable. I have a Giant Toughroad SLR, which has its 34T chainwheel at ~52mm, but I want a 36T. Should I buy the chainwheel first, stip the bottom bracket and try to measure? What clearance is okay? Tahnks if you read this :)
GREAT and very informative as per usual ... it looks like you are using a PF30 bottom bracket is that correct? and you went with a crankset with a larger Q-Factor to accommodate the oval chainring.?? The same drive gear is fitted to trance 29er 2 2021 so I like to know what size crank is fitted to that from factory
so would that mean that the longer the chainstays, the better-er the chainline? If my bike boost has 469 chainstays vs 435, the 55mm would be a more beneficial?
Just installed a M5100-1 crankset on a full suspension frame with BSA 73mm bb and 142mm thru-axle. The M5100-1 is set at 52mm. I moved the 2.5mm bb spacer from the drive side to the non-drive side. By doing so I offset my crank by 2.5mm therefore reducing my chain line from 52mm to 49.5mm. I can't go any closer as I don't have enough frame clearance for the chainring and tire clearance is close when in the 51T cog. I will be testing over the next few weeks.
@@LoveMTB Works great!. M5100-1 (32T) crankset, RD-M5100 SGS, M5100 11-51T cassette (11 speed) and CN-HG701 chain. Moved 2.5mm drive side bb spacer to non-drive side. That moved my crankset and chain ring inward by 2.5mm for a crank chain line of 49.5mm. I can't go any closer since I only have about 1mm of clearance between the chain stay and chainring. I have non-boost full suspension frame with 142mm thru axle in the rear running 27.5x2.4" tires. Only 420mm chain stay length in uncompressed position which grows by about 25mm with rear suspension compressed. Chain is a little close to the tire while in the 51T cog but seems to be okay. Took it for a ride this morning climbing in the 51T cog I was able to backpedal without dropping the chain into smaller cog. Very smooth and precise shifting for a mid-range Deore M5100 drivetrain. I'm happy!
The only issue was the chain length. Shimano recommends adding 5-6 links plus quick link with suspension in fully compressed (or longest chain stay length) for the M5100 SGS derailleur. I used this method but chain was too slack so I removed 2 links and it seems to be perfect now.
I have a question, I bought a SW EPIC EVO frame that has 52 chain lines and I bought the whole XX SL groupset with a power meter crank that is on a 55 chain line and the crank is 34T and 3mm offset. It is also possible to buy a 34T with 0mm offset. I'm not a mechanic, but I'm wondering what can I do in this situation? Please help!
Don't worry about it, just install it. And check out my mini0series on the Transmission for more info - th-cam.com/play/PLAXVoVap1M6ujA8bbEOQLDRI_ElQtvu5T.html
Does shifting gets negatively affected by moving the chainline 3 mm apart? I have entirely solved chain dropping on a 52 mm chainline by moving one of BB-52s 2.5 mm spacers to the non-drive side. Still, I wonder if that negatively affects shifting. I had SO much trouble adjusting the rear derailler to work with a SunRace CZ800 cassette that I don't want to touch anything else :(
Very good video! I want to replace my crank with an SLX and not sure which chainline. In this case, can i buy the 55mm chainline crank and in case it is too much, i swap the the drive side spacer to the non drive side and then i habe 52mm chainline? Does it make sense or sounds stupid..lol
I recently purchased a used Cannondale Habit that did knowingly need a bit of attention. After replacing a few items, including a new chain and derailleur, I witnessed what I determined excessive chain drop when back peddling. I had also replaced the bottom bracket with a new, identical Sram model (I did check OEM specs for the model) and installed spacers on each side just as they were. When checking chain line, it was off so much that it required locating both BB spacers on the non-drive side to correct the chain line. I am still scratching my head as to why this was necessary. Thoughts?
Thanks for all the great bike videos. Very clear and informative. I am considering replacing the Shimano MT510-1 (30T) crankset on my 2021 bike (new 12 speed Shimano). The axle length on the MT510-1 is 119 mm, splitting the M7100 (115 mm) and the M7120 (121 mm). That made me think that the M7120 may be the better choice because it is closer in length to the MT510-1. But... the MT510-1 has a chain line of 52 mm, same as the M7100. The M7120's chain line is 55 mm. So is the chain line the number I should focus on, making the M7100 the best choice? The chain stay of the bike has a comfortable gap with the MT510-1, but if I go to the m7100 with a 115 mm axle, does that mean the chainring will be 4 mm closer in to the chain stay? If the M7100 has the same chain line as the MT510-1, it should mean that the chainring on both will be the same distance from that chain stay. Yes? Thanks for any advice you can provide.
@@LoveMTB what do you mean if bike uses 52 chainline? is there any other factor beside the frame is designed with more room so that 52 would fit or is there some other factors as well?
Are the spacers required on BOTH sides? Not that I would do this but... what would happen if the spacer on the non drive side crank was not installed? The would effectively increase the drive side by 3mm, right? But would the missing spacer affect performance? Asking for a friend.
Then the spindle would shift side to side as you pedalled, along with your chainring. The spacers keep the cranks centered in place relative to the bottom bracket.
Hello, I'm running into a chainline problem but with sram crankset with the same bike. I purchased a crankset (Sram xo1 170mm with 34t chainring boost/3mm offset) 52mm chainline. Would 0 mm offset 34t chainring fixed the 55mm chainline problem? or would a "wide boost" crankset/55mm chainline crank will fix the problem? Thanks you, love your videos
So with the Boost frame, Wheel set, SLX 12 speed 10T-51T cassette and the press fit BB92, should I get a M7100 crankset (52mm chain line) or M7120 crankset (55mm chain line)?
Hi, i'm about o buy the same frame in xl size. I've bought an xtr 9100-1 crank. Yeti says i should use an 9125 model. I'm running 34 t chainwheel. I work at a bikeshop as a mechanic. That was the only model that was on stock. Got a annoying right knee, so a small q factor is important to me. Will the crank arms rubb the frame. Or should i look out for a different frame. ?
Good Video How about SRAM Crankset ? Are the Spindles all the same for 49mm,55mm and super boost chain line ? I think Sram just using 6mm ,3mm and 0 offset chainring.
@@LoveMTB got a 2011 Cannondale Bad Boy, converting to a 1x10, originally had a triple Crankset, shell is BSA 68mm was going to either put a 10 speed XT Crankset or try to put a China CNC Crankset looks quite nice has lots of drilled dimples on the Crankset arms.alao has 24mm aluminum spindle. Spindle length is 112mm where bearing rides +13mm for Crankset interface
I just ordered a 28T XT chainring for my SLX cranks, as they came with 30T, but I want lower gearing. Do you know of anyone making a fully compatible 26T chainring? Thanks!
I have the yeti in a medium, you mentioned about chainstay might be a factor. Wondering if your bike is a large? For my yeti 140, yeti said to use the XTR 9125 with chain line 55 and 174 Q factor. This is the first time for me.
I find the wider chain line favoring the smaller cogs to be less practical. Most the time when I back pedal on the largest cog the chain will drop making it hard to climb. I would prefer the chain line to favor the largest cog the same way it favor the small. Think this would work better. When in largest cog and backpedal no chain drop, when in smallest cog back pedal if rides up that won't be so detrimental to descending or flats.
Finally I understand what is what. Thanks so much :) As for what I use currently on my non boost frame, I have no idea it's regular XT M8000, so I am guessing 49mm or 52mm?
Good information. It really seems between the limitations of boost, wanting to run wide tires and frame designs while not having the chain fall down the cassette when back-pedalling that we're pushing the limits... too bad superboost wasn't the common standard.
@@LoveMTB I did not. What did We Are One do with their chainline on superboost? I have superboost and even 55mm CL still seems like much on the big cog, so I'm definitely curious
@@LoveMTB Good to hear because I'm also running 55mm CL (DUB regular cranks, 0mm offset ring) on my superboost rear (2019 Knolly Fugitive). Gives me good chainline and low Q factor. Honestly I'd go even more in-board if I could but the ring would hit the chainstays. In steep mountainous areas we spend A LOT of time in low gear and I realy don't care about chainline for the high gear. My last bike had an elevated chainstay so I could get that chainring in close toward the tire
XTR comes in M9100 vs M9120 both 52mm chainline but QF is different. How do I know which one I need for my boost frame? I’m currently using SRAM Eagle 3mm offset Boost chainring and SRAM GX cranks.
You're the go-to resource when it comes to buying shimano stuff. I mean it's often more useful than the official Shimano resources. Thanks a lot!
Glad to help and thanks for sharing your experience!
Thanks for these Shimano comparisons! These details are so important. The headache of ordering the wrong part is maddening. Bike shops don't always have the most informed staff these days. So you have to know what you want.
@@LoveMTB hay love mtb the shimano cranks m8130 super boost The thickness of the joints is 4,5mm ?
I’m trying to run 49mm chain line cranks on a 52mm frame/wheel set and a 3mm offset chainring. Not having any luck very noisy drivetrain. Any ideas? 6mm offset chainring ?
@@LoveMTB In the taller 2 or 3 gears chain must be rubbing on cassette because of the sever angle in the alignment of the cassette vs chainring. I'm running boost wheel set and trying a 140mm length cranks that are meant for non boost, 49mm chainline. Any ideas as what to try next? Current chainring has a 3mm off set.
Hi i tried ti install a deore 6100 crankset on my 2019 specialized chisel but found out that the deore 6100 spindle length is short for my frame, would the deore 6120 spindle length be enough or do i need to get the deore 6130, hope you could help me out.thanks
Bike shops are useless.
Thank you for all the useful info. I just order a 8120 crankset and I thought I made a mistake. After watching your video and check the Shimano website manual, I can confidently install the crank. It’s amazing that you included every detail we need, even the spacer direction! Thank you
Glad to help
This channel is the best, you always cover all the details I wonder about that no one else seems to cover. I recently purchased the M7100 crankset for my boost frame and was confused between if I should get the M7120 or not. It was confusing that both were listed for boost frames. With the 7100 the 32 tooth is pretty close on my frame but is still good enough to run like that, but for now I’m running a 30T Oneup as my cassette is only 42T. I’m in the easiest 2-3 gears for a lot of my slow technical riding so glad I ended up with the 52mm chainline. Not being able to run an oval or 34T isn’t a big deal for me but this video is very helpful to help people decide between the options.
Maybe it is possible to get the spacers separately and test it out?
Also when do we see the ARC-build??? I want one after the frame video....
Perfect video at the perfect time for me. I ordered the XT8120 and then realized the chainline difference of 55 than 52 from the 8100. This video has explained what I needed to know and has eased my mind. I'll be installing it this weekend hopefully.
When dealing with so many standards for components it's easy to get discombobulated and confuzzled. But you my friend are so thorough, and I mean thorough. I come back and realize new things that I missed months ago. Thank you man seriously 🙏🙏🙏
@@LoveMTB you're welcome btw my exact issue is my bike frame has a chain line of 52mm but like a bone-head I got SLX-M1720 w/ 55mm. Any suggestions?
Catching up after 10 years of inactivity. Man did the things change. Great info.
Happy hunting!
@@teemu3370 taks on its own nowadays, but I did manage to score sweet BMC.
wait until the wheel rim will be a gear
IKR! Same here.
Great video! My experience with the new Shimano cranks is that they are providing three sizes for quite a few scenarios and, in many cases, the chain lines are not ideal and often push the chain outboard. If you're riding areas are slow and techy and you spend a lot of time in the bigger cogs, it's lousy! There's options to fine tune this though.
For threaded bottom brackets you can buy a bag of varying width spacers which would allow you to move the chain line a couple millimeters. You can also change out those 3 MM shimano spacers with some wheel manufacturing spacers and stack a different amount on either side to fine tune (e.g. 1mm on one side and 5mm on the other). Both my bikes put the front chain ring dead center on the cassette.
Curious, do you notice the difference between the spacings in your knees, or pedaling? I like this option, but curious about the spacing not being even. Thanks.
@@dancing8595 good question. I had a superboost setup before and I’m more comfortable with the regular boost spacing
Your video helped me so much, I got a Shimano SLX M7120 crankset & BB installed by my local bike shop and I was doing a mid season cleanup and re-lube when I removed the crankset and both spacers were installed on the drive side, it just didn’t look right I was confused because the spacers didn’t seem to be built to be placed together, after watching your video everything started to make sense, I immediately looked it up in the Shimano manual for some redundancy and was able to confirm it! I guess some local bike shops cannot be trusted, thanks so much!
@@jduran30 glad you got it all sorted out 😊
I love the Shimano rear mechs but I almost always pair with a Sram crankset.
My thought on chainline these days is generally to get the chainring as much inward as possible.
I’m currently in the middle of a retro build; a 26 inch rigid frame I’m converting from a 3x to a 1x11/12- this was very helpful!
You're welcome! Andf have fun with your build, winter is the season 🙂
Question - since the 26 wheels are smaller have you considered going for the 1x11 GS derailleur and 11-46 cassette? It fits a lot better than the 12 speed. Just a thought
@@LoveMTB Answer:
Yes and thanks for asking. Here's complete analysis and my requisite flow chart for Circa 92' Univega w/ unique AMP parallelogram fork:
1) XTR Thumbshifter a must
2) Tubeless, conversion? If possible would go along way to keeping me on my existing wheel set and hub. Cane Creek straight pull and they've been great.
3) Wide range is a must. I pull a BOB trailer at times inclusive of ball end skewer.
4) End result- An ugly sleeper/Townie/Adventure/ Do whatever ride I can chain lock to a pole and still come back to it.
5) Very much considering XTR 1x simply to keep wheel set, even if I have to stick with tubes.
In a perfect world I'd stick with XTR 2x on my existing wheel set converted to tubeless however, the writing is on the wall and all this is moot if product is unsupported into the future; hence urge towards 1x12.
End game simply: to not leave another frame to the landfill. Repurpose, reuse, refuse disposable culture. Provide work to men in a shop not corporations and offshore manufacture.
It's rather personal to me. We start the build in the next couple of weeks.
Any advice would be much appreciated.
Thank you. You've got a wonderful channel!
Well I'm running 2x11 on my 2010 stumpy with the deore 48.8mm chainline nonboost crankset very smooth shifting. Thanks for this video, I feel like I understand q factor and chainline much better now.
I did suspect chain line falls onto smaller part of the cassette always. Also on mine mixed groupset hack. Despite 10sp cassette is narrower, but that width comes from left side not going into spokes as much. So 1st gear chainline is benefiting the most, plus derailleur gets more spoke distance, which makes the derailleur much less stressed out not having to work so close to spokes 😋
Hi there, I had a problem trying to fit oval chainrings to my bike. Most aftermarket ovals have offset which varies depending on type of crank. I found out from the my bike's frame model(boost) is made for 52mm chainline...The bike comes with deore m5100 crankset 32t (11speed) which is has a 52mm chainline. This particular crankset can be used on non boost and boost frames. Same goes for the shimano crankset lineup 52mm chainline m6100/m7100/m8100.(The m6120/m7120/m8120 are 55mm chainline)...However when used on a boost frame like mine. It will give you a very tight clearance especially if u go up to 34t or an oval aftermarket..I would not be surprised if the oval can't fit even with 30t ones because most ovals have offsets bringing the chainring closer to the frame.
I had to find a solution if i ever want to get a chance to use aftermarket oval chainrings on my bike. Adding spacers to the drive side of the bb to bring out the crank doesn't cut it... This is because you are shifting the crank outboard and it will be a problem to install the left non drive side crank arm. There is not enough to grab onto the spindle and it will not be safe. I know from experience coz mine flew off 😵💫 when I did this.This is for shimano cranks as the installation of the crank is different from other brands.I know I had to get a crankset with a longer spindle to accomadate the offset that comes with an oval chainring..
My solution was to purchase the m6120 (12 speed) with a 55mm chainline..next was the oval chainring from Garbaruk in 32t. The chainring model I purchased states it for m7100 series and the 8100series crankset. However, as long its for the direct mount shimano chainrings it would fit across all models with the exception of the M9100 series(XTR)...I think its because the xtr direct mount requires a different lock ring for the chainring(internal).This oval chainring from Garbaruk has an offset of 3.3mm. My bike ideal chainline according to the manufacturer is 52mm. So, 55mm (crankset chainline) - 3.3mm (oval chainring offset) gives me a 51.7mm chainline which is very close to what I was aiming for.
My conclusion, if your frame is boost 148mm. Get the 55mm chainline cranks. This enables you to shop around for an aftermarket chainring be it for round or oval ,from different brands and choose an offset and how large a chainring that can fit ,that is ideal for your frame. Do take note some chainrings brands for 12 speed shimano needs to be used with the shimano 12 speed hg+ chain only...I chose Garbaruk coz their chainrings are compatible with all speed (9 and above) chains no matter the brand..check their website.
If your frame (boost) chainline is 52mm and you get the 52mm chainline shimano crankset, you are limited to probably a round chainring with max of 34t depending on your frame clearance.Also the chainrings must have zero offset because with an offset the chainline will be lesser than 52mm.Unless your frame is meant for maybe a 49mm chainline?
Just sharing my experience so to help others who are in dilemma of finding the right cranks to fit their bikes.
Great wright-up, have the exact same problem.
Thanks so much for this - I'm in a similar situation and trying to figure out how to make my chainline work with clearance for an oval chainring. I'll be ordering a Garbaruk chain ring it seems!
Yes! You made something complicated easy to understand, and very precise.
I think it's funny that Shimano finally went direct mount but chose to produce two piece units with a spider attached to the chainring. Aftermarket options look so much cleaner!
And still no oval chainring. Which has been a huge help with my kneepain.
@@mtbboy1993 Same here. I also went down to 170mm cranks which helped.
We have a manufacturers in the UK called Superstar Components and Uberbike who provide high quality chainrings at much lower prices than Absolute Black. I must have 5-6 of various shapes and sizes lying around.
@@benmillns8976 getting those will cost same as the Absolute black probably due to added value tax of 25% and shipping cost to 🇳🇴. So I get absolute black. I've not tried superstar components. Absolute black is sold in Norway, its easy to get, I got lucky to get one second hand for good price, even got Renthal Apex stem secondhand. 👌
It’s two piece because the ring is steel or titanium in XTR.
This channel is equivalent to Sheldon Brown, just in a different format. Such great information!
Thank you, I am humbled.☺
For Shimano 12 speed and non-boost frames, Garbaruk is the best option because they propose chainrings with excellent chain lines and ovals.
Great video, as always 👍
Man, you always hit every single aspect and spec of whatever it is you're reviewing.... always so good. I was a devout Shimano crankset user myself before my Chameleon came with a SRAM DUB crankset, and I'm now a Kool-Aid drinking DUB disciple. I love their BB and the overall design of the cranks, as well as the simple offset in the chainring that allows my cranks to move between bikes with only a new chainring. As for that chain line on all of our 12speed transmissions...... yikes! Come on gearboxes and get here already.
Your level of good information is quite simply the best around ! Every time you put out a video I learn something and I consider myself fairly knowledgeable. I'm struggling with chain line on my '16 Trek Fuel EX8 and buying a new crank soon. Settled in on a Race Face Turbine so I'm hoping there will be enough adjustment to correct mine as well. Keep your channel rolling.. it's quite good and very helpful.
Did you buy the race face set yet? I am in the same market. I have a goofy boost 141 (148. W/qr) so I need the 55mm chain line. I’m interested to know how to achieve this with Race Face products
Thank you so much for this video. I Blindly ordered a M6100 to upgrade from 1x10, to 1x12. Luckily my 148 boost frame has an aggressively indented chainstay at the crank. I measured the shaft on the old crank and it was 115mm just like the M7100. Thank goodness!
i decided to go with 55mm chainline as the Q-factor is same with my older crank M5100. Not liking the 55mm offset, but I need the chainstay clearance for my crank boots.
Wow. I've learnt so much from your videos, and I haven't even have a bike yet. I'm still shopping for parts and you sir helped me a lot on what to get and what to avoid. With everything I learned so far, I'm pretty confident that my first mtb build will be enjoyable and should last me a long time before needing an upgrade. Thanks!
Thank you so much for the info!!!! I recently bought a rocky mountain growler 50. I decided to go with an oval chain ring system from one up components only to find out that the deore cranks don't support direct mount spiders / chain rings. I have been racking my brain with all the new superboost vs boost and so on. I found a set of slx cranks that support direct mount of the oneup system and this vid actually clarifies nearly a week of research I have done. thank you again!
Hi, nice to meet you here again after that “strange blackout”.
I wanted to share with you an trouble that is really becoming a bother to me.
My mountain bike is old enough for having a non-boost frame and so unique to have a PF30 bb shell 68mm wide (and 46mm diameter).
so when I upgraded to twelve speed I bought a brand new GARBARuk 6.4mm offset chainring with my new M8100 crankset.
Long time before I changed the former Shimano bottom bracket with a Token Fusion PF30PS one.
This time I took my bike to my mechanic to mount the chainring and the crankset. So I didn’t notice anything special.
But lately I went further with my bottom bracket looking for a noiseless bike and changed that Token bb with a custom mix of clean PF30 rollers (a minimal cup with the 30mm inner diameter roller) and I kept the old Token PF30 to 24mm adaptor.
So when I put the left crank arm I noticed that it didn’t fit to the axle even with no washer. So I took measures and I got a bit disturbed.
this is what I got comparing M-8000 vs M-8100 crankset.
th-cam.com/video/NEWraGuNGrM/w-d-xo.html
That's a weird one. Did you solve the mistery?
And yeah, great to be back!
I'm looking to upgrade my cranks and this really helped me understand the differences. Thank you!
You're very welcome
I was recently looking at upgrading my older RF Turbine crank to Next R and had a look at the RF Q-factor Chainline guide. They have 148 boost paired with a 52mm chainline which is quite a difference from Shimano's 55mm. Also, doing my own measurement, 52mm places the chain in a straight line from the crank to the middle cogs of the cassette on a boost frame. Haven't seen any other sources indicate 55mm for boost and I saw in your video that the angle of the chainline to the largest cog gets fairly extreme with the 7120 (55mm) crank.
This video is very timely as I'm about to build my first boost mtb, thank you for this!
This is so useful I can barely find this information explained this well online let alone a TH-cam video. Please do more of these types of videos!
I am using 11 speed with 52mm chainline boost I just installed a new GX 170mm crank from my old NX 175mm crank and I love the new one no problems! Cheers!
You get a like yes or yes.
I have been doing this investigation about chainline on 12s drivetrains for ages, and there are no other videos out there expalining this as good as you do.
I am waiting for my 2x10 to die (142mm) to upgrade to 1x12 and have always been worried about not having options for a 49mm chainline.
I now see 52mm should do OKish with my setup. hoppefully I can install a 34 teeth chainring at the front and not hit the chainstain..
Thanks, very educational videos that address everyday bikers concerns.
I get so much information about specifics from this youtube channel than other channels
I am using 52mm on my 135mm bike for 1x12 XT with no problem... dont be afraid of it ... 51 cassette is little bit extreme but I try not to use it so often ...
Thanks for confirming, it is what Shimano says also!😊
Good info. I think that you just explained why garbaruk offers a custom offset. The standard offset is 3.3mm and the custom is 6.4, Seems like it is intended to give [6,7,8,9]120 owners and option for are narrower chainline.
I'm using fc-m7120 on both of my boost bikes. To give a better chainline I'm running the two 3mm spacers on the non-drive side of both bikes.
That makes no sense. The 7120 is the wider of the two cranksets shimano recomends for a boost frame with a 55mm chainline. If you add an additional 3mm spacer on the drive side you are making the chainline 58mm which is more than Shimano's recommended chainline for a super-boost frame.
I removed a 3mm spacer from the drive side not added! 😅
I'm considering doing something similiar. I'm not happy with the chainline on my kona unit x with boost wheels and m8120 crank. have one 3mm spacer on each side as specified but it makes the low gears run like crap. Since its a bikepacking build im going to be in that low gear a lot.
Thanks for doing this video, building up a new frame and you've just helped with my last problem, which chainline. Good to also know that the tool only comes with the full crankset.
World-class professional explanation. Very clear and useful. Tons of thanks.
Some of the best advice online. Thanks for your help.
Glad to help🤜
It’s so easy to order the wrong part these days thank you for your videos I just ordered a 175 crankset luckily I got the right part 🤩 M9100 xtr I was confused because the non-drive side arm reads 9100/9120
But the Drive side only reads 9100 it’s perfect now I can hammer my new longer arms
Okay, so if I am using a non-boost frame and a 12 speed 1x, then the chainline shouldn't depend on the cassette. It should always be 52mm, right? I usually align with no. 6 cog from the smallest. Is that why I get a slow down-shift from the largest?
I have a Ritchey Ultra frame with 148 mm boost spacing and based on the Ritchey website, the chainline for this frame is 52 mm. I am running XT 8100 cranks and everything seems to run fine.
Running m7100 (52mm) with 32t round on a Yeti arc, wondered why the clearance is tight AF. This is an extremely useful video. I'm going to keep running as I am for now, especially since I get a better chainline in a hilly area, but it is super tight! No way could I go oval or 34t. Great video, thanks!
For 49 mm chainline you can use aftermarket chainrings.
So if I’m understanding this correctly. Quick and easy way to seeing which chain line you have is took look for what size spacers you bike has? If any
During my Chameleon build, I was pulling my hair out trying to fit a Shimano crankset, especially since I plan on running the bike with a short 415 chainstay (they are adjustable up to 430). I wish you had released this video a month ago - a great summary of the current Shimano crankset offerings. You would have saved my several hours of research. HA!
My Chameleon, like your Yeti needs cranks with a Q factor larger than 172 mm for clearance. However I really need to run a chainline as close to 52 mm as possible or my dang chain will drop off at the slightest back crank. So the Shimano cranks were a no go for me. There is a reason these bikes come spec'ed with Sram cranks and I wish Shimano would figure this out. I bought Raceface cranks instead.
@@LoveMTB Yes RF does have varying spindle lengths. I have the Aeffect R cranks on order with a 137 spindle, 175 Q factor and 51 mm chainline. No rides on the bike yet, still waiting for the fork to come in. :-(
Super informative as always. I originally installed the XT FC-M8120 with 55mm chainline crank on my BOOST frame, but found the chainline a bit to extreme and my chain was actually dropping when backpedaling on the largest two cogs. Replaced the crank with the XT FC-M8100 with 52mm chainline, which the frame still had tons of clearance for and now everything is great. The chain stays on my frame are 420mm.
The same thing happened to me. My bike came with an XT M8120 and I exchanged it for an XT M8100. At the moment I have a 32 tooth plate. When I go to mount the 34 I will see if I have space, if not, I will mount the XT M8120 again. It is an Orbea Oiz M10.
Might be a stupid question but could you just run 2 spacers on the non drive side and non on the drive side to get 52mm chain line?
@@LoveMTB Because you made a purchasing error :) I have mine set-up the correct way with 73mm bb and it seems larger than 55m chainline so need to put both specers on the non drive side.
WHY? WHY? WHY does Shimano recommend 52mm chain line for 135/142 frames? I spaced my M5100 crankset chainring (96 bcd) from 52mm back to 47.5mm by using 4.5mm worth of spacers and longer 16mm chainring bolts. Wish I didn't have to do that. Wish Shimano made a 1x crankset with 48mm chain line for their newer drivetrains. I'm loving the Deore M5100 drivetrain, just wished they made a crankset with 48mm chain line. My chain stays are only 425mm so 52mm chain line angle was too extreme. I do a lot of climbing in 51T cog. My drivetrain works perfectly, but only because I reduced my chain line to 47.5mm. No problem backpedaling on 51T cog.
I have same problem .. f+ck shimano, i hate this evil company i have spent touch money on single upgrade and got wrong chainline with my 73mm bb...
What spacer did you use?
@@noellereypelayo551 no spacers
@@noellereypelayo551 I placed nylon spacers between the chainring and the crankarm in order to move the chainring closer to the frame in order to reduce my chain line from 52mm to 47.5. I had to purchase longer chainring bolts. Went from 12mm to 16mm long bolts.
I had the M8120 on my 2020 Trek Fuel EX 9.8, but once I built my 2021 Banshee Paradox with the same crankset it caused terrible back pedaling (would come off top 3 cogs), I had to find a small chainline crankset. I got an M7100, which funny enough was lighter by 70 grams than the M8120 because of the shorter spindle.
Technically, crank manufacturers should make chainrings or crankarms to adopt every single O.L.D., I decide to use MT510 crankset on my 135mm QR old bike but its 52mm chain line is obviously optimized for 148mm rear axle.
I agree but I assume they did this to minimize SKUs, nothing else.
Your channel is really a bug help to MTB community 🤘🏽
Shozaburo Shimano will be proud of you!
what should be the correct chainline on those two cases: 10s on boost frame and 12s on no-boost frame?
10s uses a 49mm chainline, regardless of the rear spacing. 12s uses a 52mm chainline regarless of the rear spacing of the bike.
Very helpful thanks. Coming from a road background all this MTB stuff is new to me.
@@BrentZahradnik it’s ok I feel the same about the road stuff 😎
Thanks for the Vid. Good stuff as usual. On my Sb150 I ended up put the spacer on the NDS side to get a better chainline, and it eliminated drops on backpedal on largest cog.
@@LoveMTB I'm loving it so far but I haven't tried it on real proper rough trails other than one weekend, so I look forward to putting some time on it this season. I just ordered a Mara Pro as I am not completely happy with the X2. Normal days I ride a smaller 120mm bike. Will you be making a review and bike check on your steeds at some point? Since you do spend some time tinkering and thinking about specs I think it could be interesting. Also if you do your own suspension service, it could also be great content if you do full rebuilds!
Also got an SB-150 and about to fit a new 8100 crank, any idea what the part number for that spacer is, just ordered Y0JC61000 but its just a paper thin sticker, not a 3mm plastic ring like in the video
Great and very informative video!
I see from your other SLX review video that you have a 2018 giant trance 3 - it's a boost bike with stock cranks (FC-M7100-B) that have a 3 mm offset and 172 Q factor - if I'm going to upgrade to SLX 1x12 should I be getting the FC-7100 that better matches the stock config? I'm worried that the FC-7120 with 55 mm chainline would be problematic with the 51t as you mentioned.
I would go for the 52mm chainline if the bike permits.
I used the M6120 on my boost frame. Chainline was way too outward when using the larger cogs. I think it varies with bike to bike. Does not mean M6100/7100/8100 is definitely for non boost or that M6120/7120/8120 is for boost etc. I also contacted Transition about this and they actually recommended the M6100/7100/8100 on their bikes though they are boosted frame. So best is to check with the bike manufacturer.
To fix that chain line grab this spacer kit:
www.amazon.com/gp/product/B07N4CSRS8/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
Just make sure the total spacers equal whatever Shimano gives you.
@@tinshield Chainline is too outward though still usable. Adding spacers will make it worse right??
@@mf3616 not if you add a 1mm spacer to the drive side and add the balance to the non-drive side.
@@tinshield It will not feel good while pedaling mate. Feet placement will be all over the place.
@@mf3616 that’s false. It’s not enough variation.
I wish I knew this before I ordered 7100 for my boost mtb frame. If I add any spacers the safety clip does not clear the hole on the non drive side of the crank shaft as it does not stick out enough. My workaround is no spacers.
7100 should work just fine with Boost, it’s the chainline that the manufacturer of frame prefers that makes it interesting
@@LoveMTB I've got an aftermarket oval chainring that sits about 2mm farther out (offset?) than the factory shimano one. Problem solved - sort of.
Great video best explanation on TH-cam. Especially the spacers. No one mentions that.
Great video. This helped me resolve an issue I was having on my Chromag Rootdown. I was looking at installing an older M780 Crank but the spindle isn't long enough. Shimano specify Qfactor but not the actual spindle length. Looks like I need an 8120.
Dumb question... when a chainring offers 3mm offset, is that outward or inward? Assuming outward? So if I added a 3mm offset chainring to the SLX M7100-1 it would give me a 55mm chainline?
It’s inward and Shimano does not use/ provide different chainline chainrings only some 3rd party and XTR replacement specific
Great Video great explanation, althought sram groupset on my bike. Installed my 55mm cranks even though my bike has a 52mm chainline and I have to say everything works great. You are doing a great job my friend. Thank you 👍🏻😀
I thought I was watching about mountain bikes, turns out to rocket engineering. Cheers great in depth understandable information.
Using Garbaruk 6mm offset chainring with M7100 SLX crankset on 135mm rear hub - chainline now great!
@@LoveMTB Great video thank you. Manufacturers are not making things easy for the average Joe.
Hello dear, could you help me with a question, my boost 148 frames are for 27'5 plus 2.8 wheels, the most recommended cranks are 7120 Qfactor 178? Does 7120 work for chain line 52 and 55 or only 55? thanks
55mm with the standard chainring
How do I know in advance, which crank length I need? I doesn't look something that is accurately measurable. I have a Giant Toughroad SLR, which has its 34T chainwheel at ~52mm, but I want a 36T. Should I buy the chainwheel first, stip the bottom bracket and try to measure? What clearance is okay? Tahnks if you read this :)
GREAT and very informative as per usual ... it looks like you are using a PF30 bottom bracket is that correct? and you went with a crankset with a larger Q-Factor to accommodate the oval chainring.?? The same drive gear is fitted to trance 29er 2 2021 so I like to know what size crank is fitted to that from factory
@@LoveMTB Righ so you didn't use the one ticked in your vid .. it threw me ....
so would that mean that the longer the chainstays, the better-er the chainline? If my bike boost has 469 chainstays vs 435, the 55mm would be a more beneficial?
Just installed a M5100-1 crankset on a full suspension frame with BSA 73mm bb and 142mm thru-axle. The M5100-1 is set at 52mm. I moved the 2.5mm bb spacer from the drive side to the non-drive side. By doing so I offset my crank by 2.5mm therefore reducing my chain line from 52mm to 49.5mm. I can't go any closer as I don't have enough frame clearance for the chainring and tire clearance is close when in the 51T cog. I will be testing over the next few weeks.
@@LoveMTB Works great!. M5100-1 (32T) crankset, RD-M5100 SGS, M5100 11-51T cassette (11 speed) and CN-HG701 chain. Moved 2.5mm drive side bb spacer to non-drive side. That moved my crankset and chain ring inward by 2.5mm for a crank chain line of 49.5mm. I can't go any closer since I only have about 1mm of clearance between the chain stay and chainring. I have non-boost full suspension frame with 142mm thru axle in the rear running 27.5x2.4" tires. Only 420mm chain stay length in uncompressed position which grows by about 25mm with rear suspension compressed. Chain is a little close to the tire while in the 51T cog but seems to be okay. Took it for a ride this morning climbing in the 51T cog I was able to backpedal without dropping the chain into smaller cog. Very smooth and precise shifting for a mid-range Deore M5100 drivetrain. I'm happy!
The only issue was the chain length. Shimano recommends adding 5-6 links plus quick link with suspension in fully compressed (or longest chain stay length) for the M5100 SGS derailleur. I used this method but chain was too slack so I removed 2 links and it seems to be perfect now.
I am a slim person of 63kg, I am 1.90 meters tall. What size crank should I choose?
I have a question, I bought a SW EPIC EVO frame that has 52 chain lines and I bought the whole XX SL groupset with a power meter crank that is on a 55 chain line and the crank is 34T and 3mm offset. It is also possible to buy a 34T with 0mm offset. I'm not a mechanic, but I'm wondering what can I do in this situation? Please help!
Don't worry about it, just install it. And check out my mini0series on the Transmission for more info - th-cam.com/play/PLAXVoVap1M6ujA8bbEOQLDRI_ElQtvu5T.html
FC-M7100-1 FOR 68-73mm BSA FRAME SHELL ??? Correct ? Love MTB
Great video. Can you make one for SRAM cranks? thanks.
Good suggestion 👍 meantime I have a DUB BB video that kind of talks about this
Does shifting gets negatively affected by moving the chainline 3 mm apart? I have entirely solved chain dropping on a 52 mm chainline by moving one of BB-52s 2.5 mm spacers to the non-drive side. Still, I wonder if that negatively affects shifting. I had SO much trouble adjusting the rear derailler to work with a SunRace CZ800 cassette that I don't want to touch anything else :(
Good day. Love seeing your videos. So if my frame is Giant XTC SLR boost 148, ideally the M7120 is right for me?
Very good video! I want to replace my crank with an SLX and not sure which chainline. In this case, can i buy the 55mm chainline crank and in case it is too much, i swap the the drive side spacer to the non drive side and then i habe 52mm chainline? Does it make sense or sounds stupid..lol
You got it right!
Hola te felicito por el buen video
Una pregunta para saber q linia de cadena es la correcta en mi bicicleta y como sacarla y como ajustarlo
I recently purchased a used Cannondale Habit that did knowingly need a bit of attention. After replacing a few items, including a new chain and derailleur, I witnessed what I determined excessive chain drop when back peddling. I had also replaced the bottom bracket with a new, identical Sram model (I did check OEM specs for the model) and installed spacers on each side just as they were. When checking chain line, it was off so much that it required locating both BB spacers on the non-drive side to correct the chain line. I am still scratching my head as to why this was necessary. Thoughts?
@@LoveMTB I actually have room to add more but it would not benefit in any way
Every week I get bike smarter ! Thank you!
Thanks for all the great bike videos. Very clear and informative.
I am considering replacing the Shimano MT510-1 (30T) crankset on my 2021 bike (new 12 speed Shimano). The axle length on the MT510-1 is 119 mm, splitting the M7100 (115 mm) and the M7120 (121 mm). That made me think that the M7120 may be the better choice because it is closer in length to the MT510-1.
But... the MT510-1 has a chain line of 52 mm, same as the M7100. The M7120's chain line is 55 mm.
So is the chain line the number I should focus on, making the M7100 the best choice?
The chain stay of the bike has a comfortable gap with the MT510-1, but if I go to the m7100 with a 115 mm axle, does that mean the chainring will be 4 mm closer in to the chain stay?
If the M7100 has the same chain line as the MT510-1, it should mean that the chainring on both will be the same distance from that chain stay. Yes?
Thanks for any advice you can provide.
@@LoveMTB I recently bought and Installed the SLX 7100 with the 52mm chainline and it fits great. Thanks for the excellent advice!
@@LoveMTB what do you mean if bike uses 52 chainline? is there any other factor beside the frame is designed with more room so that 52 would fit or is there some other factors as well?
yeah, shimano's chainline got crappier and crappier, personally I moved the BB spacer from the drive side to the left.
Are the spacers required on BOTH sides? Not that I would do this but... what would happen if the spacer on the non drive side crank was not installed? The would effectively increase the drive side by 3mm, right? But would the missing spacer affect performance? Asking for a friend.
Then the spindle would shift side to side as you pedalled, along with your chainring. The spacers keep the cranks centered in place relative to the bottom bracket.
Hello, I'm running into a chainline problem but with sram crankset with the same bike. I purchased a crankset (Sram xo1 170mm with 34t chainring boost/3mm offset) 52mm chainline. Would 0 mm offset 34t chainring fixed the 55mm chainline problem? or would a "wide boost" crankset/55mm chainline crank will fix the problem? Thanks you, love your videos
So with the Boost frame, Wheel set, SLX 12 speed 10T-51T cassette and the press fit BB92, should I get a M7100 crankset (52mm chain line) or M7120 crankset (55mm chain line)?
Hi, i'm about o buy the same frame in xl size. I've bought an xtr 9100-1 crank. Yeti says i should use an 9125 model. I'm running 34 t chainwheel. I work at a bikeshop as a mechanic. That was the only model that was on stock. Got a annoying right knee, so a small q factor is important to me. Will the crank arms rubb the frame. Or should i look out for a different frame. ?
Good Video
How about SRAM Crankset ?
Are the Spindles all the same for 49mm,55mm and super boost chain line ?
I think Sram just using 6mm ,3mm and 0 offset chainring.
Very similar on SRAM, check my last video on T-Type Cranksets
@@LoveMTB how about Road Crankset can a Road Crankset fit. MTB frame ?
@@jonienglish3231 what are you trying to do?🤔
@@LoveMTB got a 2011 Cannondale Bad Boy, converting to a 1x10, originally had a triple Crankset, shell is BSA 68mm was going to either put a 10 speed XT Crankset or try to put a China CNC Crankset looks quite nice has lots of drilled dimples on the Crankset arms.alao has 24mm aluminum spindle. Spindle length is 112mm where bearing rides +13mm for Crankset interface
Well, nice and complex explanation. Thank you.
You are welcome!
I just ordered a 28T XT chainring for my SLX cranks, as they came with 30T, but I want lower gearing. Do you know of anyone making a fully compatible 26T chainring? Thanks!
I have the yeti in a medium, you mentioned about chainstay might be a factor. Wondering if your bike is a large? For my yeti 140, yeti said to use the XTR 9125 with chain line 55 and 174 Q factor. This is the first time for me.
Very helpful video, but can i use a M6120 on a non boost bike? Or its just not compatible?
What is the difference between boost and non-boost cranks? Is it just the chainring offset (3mm/6mm) and cranks are the same?
I find the wider chain line favoring the smaller cogs to be less practical. Most the time when I back pedal on the largest cog the chain will drop making it hard to climb. I would prefer the chain line to favor the largest cog the same way it favor the small. Think this would work better. When in largest cog and backpedal no chain drop, when in smallest cog back pedal if rides up that won't be so detrimental to descending or flats.
Finally I understand what is what. Thanks so much :)
As for what I use currently on my non boost frame, I have no idea it's regular XT M8000, so I am guessing 49mm or 52mm?
Hi. Great video. Will this slx crankset work for 11speed shimano as well?
Yes no problem
@@LoveMTB thanks man. Ride safe 😃
This video was super helpful and exactly what I was looking for. Thanks so much!
What is the best chain line for you 55? Or it depend of the mtb hardtail trame?
Good information. It really seems between the limitations of boost, wanting to run wide tires and frame designs while not having the chain fall down the cassette when back-pedalling that we're pushing the limits... too bad superboost wasn't the common standard.
@@LoveMTB I did not. What did We Are One do with their chainline on superboost? I have superboost and even 55mm CL still seems like much on the big cog, so I'm definitely curious
@@LoveMTB Good to hear because I'm also running 55mm CL (DUB regular cranks, 0mm offset ring) on my superboost rear (2019 Knolly Fugitive). Gives me good chainline and low Q factor. Honestly I'd go even more in-board if I could but the ring would hit the chainstays. In steep mountainous areas we spend A LOT of time in low gear and I realy don't care about chainline for the high gear. My last bike had an elevated chainstay so I could get that chainring in close toward the tire
Is there no way to offset a Shimano m6100 direct mount chainring to make it 48-50mm instead of 52?
XTR comes in M9100 vs M9120 both 52mm chainline but QF is different. How do I know which one I need for my boost frame? I’m currently using SRAM Eagle 3mm offset Boost chainring and SRAM GX cranks.
Do you experience chain drop when backpedaling with the 52mm chainline?
My 8120 cranks didn’t come with those 3mm spacers but they work fine? Weird. I can’t even find that part online.