Shimano Nexus 8 Speed Hub - Dissection! Evisceration! Destruction!
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- เผยแพร่เมื่อ 1 ต.ค. 2024
- I disassemble a Shimano Nexus 8 speed hub to see what's inside.The hub is a Shimano Nexus SG-8R20. It also had the option roller brake installed. The hub is probably as complicated as a car transmission. I ain't never getting this thing back together again! LOL!
Shimano Nexus 8 Speed Hub Reassembly - Putting It Back Together...:
• Shimano Nexus 8 Speed ...
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Just think: someone actually designed this thing.
It's amazing, you know.
Just think of the math and physics they had to apply
Reverend Al Japanese. Just look at the higher end watch movements from Seiko, or an eighties high end compact AV gear from Sony... Damn, they beat German, Swedish, Swiss engineering straight! (being a Swedish one myself)
It took more than one genius to put that together the first time. Blame it on Leonardo da Vinci for starters.
@@thomashughes_teh LOL
just play this video backwards to figure out how to put it back together lol
Big brain time
I think you need to accept the challenge of trying to clean it up and get it back together . No need to pack it full of grease just some oil to lubricate but we need to see it work again .. Please
I agree - it shouldn't / mustn't be packed full of grease
Hahaha that's my job. Do one every two, three weeks or so. I'm a bike mechanic
@@suitknol6604 How did you learn to do this? Even for a an expert bike mechanic like RJ the Bike Guy this is almost above his head.
@@jfkcamelot in the Netherlands, bike mechanic is something you can actually study at school. I went to school 3 years, every Monday, and worked Tuesday to Friday. I learned how to disassemble hubs there, among a lot of other info. I wouldn't call RJ an expert bike mechanic because not everything he says is strictly true, but he is 100% better than most. He can also do other stuff I don't have any experience with.
@@suitknol6604 Dutch, who else would have a school for bike mechanics :)
Thumbs up!
Seems suspiciously like an extraterrestrial technology.
Wait, is this the first time RJ hasn't been able to put something back together?! NOOOOOO!!!
I strongly believe he uploaded this video in reverse
There's no purer pleasures in life than completely disassembling a mechanism to see how it works.
At least that's my humble opinion.
Thanks for a great video.
I never heard "here" so often in my life!
*_H E R E_*
65 times~ish
i was telling him to shut up in my head lol
Crazy complicated for a mass produced bike hub.
Thanks for doing this. I love the Shimano Nexus gear, so incredibly robust compared to derailleur. I now have immense respect for the engineering, and will never resent paying for a gear hub. Our family have done thousands of miles on hub gears, and I won't go back. Thank you again for a very honest job!
Take a shot if you hear “in here” lol awesome video
Hahaha! I noticed the same thing! Great video nonetheless!
Right here?
That's what I was thinking too! 🙉
You evil person, now I have alcohol intoxication and need to go to hospital to pump that all out.
I’m going to leave a comment “right here”.
It's incredible on how our minds have grown sense the invention of the wheel. Just making all those little parts and putting it all together and creating that piece of machinery. Loved the video, Thanks.
I like the idea to service bikes myself so I'm going to stay away from this mechanical nightmare. Thanks !
God damn murder scene
LOL!
It is the same as a 8 speed automatic, but all in 1 axle! And way tinyer! I have done the same with a Sram I-motion 9, and it is a nice challenge. Thank hell I had a good day and did not throw the fucking thing thru the window, It still works after 5 years and lots of miles after.
When you reasemble, bath it in ATF, Works wayyy better
RJ, i do not think that you are the kind of man that would let this kind of challenge beat you, i think there is for sure going to be a Eureka moment, and the put back video is some thing for the future, in the immortal words of Sean Connery, 007 "Never shay Never, Kah peesh"
Tom Thats honestly what i was thinking 2 rj is not going to let this beat him
Rubik's Cube😬
I see what's behind the naming. It's the nexus point between sane and insane.
You would need a shop manual. With, an Exploded View. That will help you identify parts, determine their condition and, the order of assembly. Good luck with this mission. If, you decide to accept it.
japanese engineering
There are some other companies from other countries that have complex geared hubs. The Rohloff 14 speed is from Germany, and the Sturmey Archer 8 speed hub is English.
@@jtables7138 Sturmey Archer was purchased by Sunrace in 2000. Sunrace Sturmey Archer Inc. Taiwan
Funny ( here ) sound
I laughed a lot when I heared you laughing at the end. Thanks for sharing a good moment.
I think it is similar to car's gear box where the clutch isolates speeds.
This reminds me of the time I pulled apart my 24mm-105mm Canon lens! It was a 3 dimentional puzzle from hell and all the time trying to keep the glass free from finger prints. I did get it back together but was tempted to put the 100's of pieces in the bin! I too would love to see this amazing geometrical puzzle put back together again and hopefully working too.
th-cam.com/video/JNuyvIZvCrs/w-d-xo.html
Hi, i'm from Brazil. Now, i want to see you clean and assembly this again... 😁😁😁
Thanks! I wanted a faster bike at one point, mi city bike was old and slow. Found a Bianci Milano with a nexus 8. It was slower.... but way newer 😅 Even though used I couldn't resist, the internal mech was almost worth it by itself as a conversation piece 😄
It's been the sweetest ride forever and am glad I've seen some of the mechanical engineering magic out of my head and in real life 👍
Nice project partner, keep it up 🖖
I had the same situation with the seven-speed Shimano hub:)
SACHS / SRAM 3/5/7 hubs (the older ones) are so simple and ingenious in construction.
Imagine what must be inside the Alfine11 hub - a horror for a mechanic:D
Greetings from Poland!!!
Pozdrawiam...
@@maciejnowak1993 Ja również pozdrawiam!🙋♂️
Teraz to już siódemki od Shimano mam rozpracowane w 100%, a ósemki wydają się nawet prostsze w budowie od nich. Dzięki YT można sobie poradzić nawet z tymi "nieszczęsnymi" blokami sprężynowymi. Mam też specjalistyczne narzędzia do tych piast od Shimano, smary i oleje również.☺
Is anyone turned the HEREmetr on, like THIS?
These hubs are just mechanical nightmare nesting dolls, once you think you've reached the end there is another split ring and 50 more parts... Very interesting to see, but beyond what I want to attack on my own, so thank you!
LOL!
Lol.... "It works with magic" that is one complicated piece of machinery and u are one patient dude. I would have thrown that in the trash halfway through crawled in the fetal position and started sobbing.
Interesting. I came very very close to buying one of these then bought the Ebike instead. Now I understand why overseas they call them roller brakes. It looks like a roller bearing sprague clutch like use in drills and cordless screwdrivers.
The hub itself looks like it might be built to be 9 speeds but loses one because of its configuration. I think once I'd crank on it'd definitely break. Thanks for the peak inside it RJ.
Just as we all suspected, it works by magic!
You've just doen what must of us would love to do, but wouldn't dare do so with our own hubs.
Thank you.
An old "Billy Backyard Mechanic"'s trick is to lay out on your cardboard, each part removed in the order they were removed. You could even group them according to the area they were removed, ie; left side, right side, inner drum, etc. With the cardboard, you take a Sharpy pen and number each part and make any notation that helps you remember your conclusions as you disassembled it. You are lucky that you have a decent video detailing how you disassembled it. Just reverse the procedure. The funny thing is when reverse engineering you learn just as much if not more by putting the thing back together.
The hub is full of grease where it should be a thin special oil from Shimano. Probably why it didn't work. A cleaning and oil bath with Shimano oil (part no Y0029801A) would probably have solved the problem.
IGHs with more than 5 gears are usually oil-filled and oil changes are mandatory. Change with hub gear oil before and after 1000 miles (no previous oil change). Then change oil every 3000 miles. (the first oil change is at 600 miles). Use only Shimano SG-S700 Oil in the Alfine 11 hubs. Also use waterproof grease in the hub to prevent premature failure.
Three observations:
1. It really makes you appreciate a cassette and derailleur system.
2. This has a large "ick factor"! Have you considered a parts washer?
3. Great advice at the end about taking one apart!
I actually have a parts washer. I need to dig it out and replace the solvent in it. I was cleaning the parts in my ultrasonic cleaner which is pretty lightweight.
As soon as I rode IGH I appreciated time saved on cleaning multiple cogs and low running chain. This is a low end hub, I just checked Campi Record 8-sp cassette alone costs about 2/3 of this hub. Shimano 8sp cassette is about 1/3 to 1/4 of price, though.
OMG - this is one complicated gizmo. I'm glad I saw you take it apart because now I don't have to do it.
This guy has no idea what he's doing!
I've taken these apart succesfully (and put them back together again).
There is a certain point after which you should probably stop disassembly (or you're gonna have a bad time ;).
Halfway, you come across some double spring-loaded thingie. And I HAVE managed to put that back together and back on without the official tools, but it took me several hours over several days.. And a loooot of patience ;)
Anyways - Nexus gear hubs are my favorite. VERY reliable, very little service required.
Just make sure you use the Shimano recommended greases
(the rollerbrakes too - they have Moly based grease for those with a certain viscosity. (I tried lithium grease, but holy sh!t - suddenly my brakes didn't work anymore at high speed)
Oh, and look for the dots imprinted in the metal gears (easy to miss) - on the first (?) planetary gear set (3 gear wheels), the dots need to face outward. Exactly the same as eachother, or there will be problems with gear alignment...
That proper gear alignment makes it so you can shift from 1 through to 8 while standing still (it's pretty sweet)
Oh, and use the proper shifter. One made for Nexus 8
(Nexus 7 shifter works too - you just don't have the heaviest gear available to you)
Oh, and use the proper err... (I think they call em) 'anti-rotation washers'. Those things that lock the axle in place (to keep everything in position);
They have different colors for Nexus 3, 4, 5, 7 and 8.
Nexus 8 is 1 gray, 1 black
Got Nexus hubs on 3 of my 4 bikes, and I reckon I might be the only one in Amsterdam who likes servicing this system (:
Just to ask is there a road bike shifter that can be used for them?
Being mostly German - I have to credit Japanese Engineering. Why I prefer Toyota.
“It works by magic.” Ok. Moving on...wait, hey wait a minute. That’s my answer, can’t be RJ answer. I turn to experts like RJ to demystify. The room is spinning, vision narrowing, dark, getting darker, argh....
Ok mine is doing strange noises. After watch this video I just take it out and throw it out and buy another thing. What a complicated piece of s...
Drinking game: take a shot every time you hear the word "here." If you want to go to the hospital also drink for every "there". ;)
There are special tools produced/sold by Shimano for servicing these hubs. The tools simple but are kinda model-related, so you need to google proper tool part numbers for the hub. Hope this helps you re-build the hub, because that would be just wonderful (looking forward to seeing the next episode).
What kind of alien species designed this..amazing!
I much prefer the linear shifting of a Sturmey Archer. Really you should be looking for 4 different gears in there, hub gears usually have a direct drive then each speed below that is paired with one above, so a 3 speed hub will actually only have 1 gear train, it just uses it in both directions and has a bypass for Normal.
Interesting video, though I too would like to see it fully cleaned so it can be observed, surely your video can show the order and orientation of the parts as they came off
When you take it apart, carefully place your parts in the right order, watch closely how the rings and springs and other stuff sits on the axles. When you put it together again work backwards, no need for manuals. Begin with an old one.
it is like I hear him. gentlemen, welcome back to the shop, today a treat especial... same approach he did for panasuckit scruediver, put it on the healingbench and dont loose parts. i am sure you will find it most challenging to try again and again.
as the audience wisely commented, it is water that caused the premature death.
rohloff is sealed with regular oil change. i dont think after the wear tear, being it loose in the hips it is salvagable. seek to see your vids on these advanced toys.
you could develop your own ".. in a vice" end slogan
It is fascinating to see how engineers have been able to invent such complex details.
о Откуда грязь берётся не понятно ведь всё закрыто и внутри находится
the tech is old, but still so brilliant. who ever came up with the mechanism for shifting and holding the pinions in place should be named every time
Thanks for sharing that. Who makes that? Probably a 3 armed reversed foot 6 eyed Gumby troll in a deep Forrest in the middle of nowhere. Lol. Just kidding whoever it was is AWESOME.
Finally something even RJTheBikeGuy finds hard to repair! Lol, thanks for your work sir!
I started seriously to do mathematics when I was 13, now I am 43. The whole 30 years I permanently improved my math skills. Now I am a math teacher at University. I saw very complex theorems and proofs. But, I must say, that the construction of this rare gear hub is very complex. I am very much impressed by people who invented it.
I wonder if you can use ATF as a lubricant?
Great Video !! Like to see if you can put it back together !!
how many times does he said "HIERE" ? :D
in here... :-) great video btw...and fun
It looks like water got into this hub judging by the color of the grease.
Did you get it back together? There is a guy on YT who rebuilds these things.
I agree about the magic. The physical stuff is so complicated. There are some smart people working on this stuff! Just think of all the old machines built in the late 19th and early 20th century that can do whole drawings entirely on this type of stuff! They were built by literally 1 guy who often had very little schooling! Geniuses!
Who is The Guy on TH-cam send the link please I need to service mine but dont have a clue how
So here, and here, and if you here... 😂👍
looks just like one of their fishing reels
هدشي.خطير.هد البواط
خصها.انجينيور.اوتيقني
تبارك.الله.العولماء.تحياتي
اليليهم.جميع
i Have 2 of these. 1 isnt as smooth as it used to be. the other is still fine. My problem is both are on different size rims but i want to replace the worn out one my bike. After seeing this video i think i could just transplant the internal gear system within the shell that is attached to the spokes right? i am no Japanese gear hud engineer, i am just a Dutch plasterer, HELP!! lol.
Just remove the spokes from the wheels and change over. Look for videos on "wheelbuilding"
Best of luck
Have opened and took apart both the hubs i had and simply stored the parts in the correct orde of assembly, cleaned everything and simply took the best parts of both (it were the bearings that needed replacement) hubs and assembled 1 good working hub. Looking back it took me about 6-7 hours incl. cleaining and relubricating the entire thing. It was not nearly as hard as this video makes it seem, just work systematic and one should be fine!
@@dutchkendama well! Turns out you're not 'just a Dutch plasterer' you're a self taught engineer/technician! And braver than most. Pretty cool.
It looks like Shimano used automotive design and built a miniature automatic transmission. I wonder which transmission the Nexus is based on.
Thanks RJ for another great educational video.
It runs on a Toyota's variant of an auto tranny
Wow, that is nasty inside! I can hear the friction from heeerrrrrree!
Albert clean it first.
I shall leave that alone then.
Try to assemble it RJ
And if u cant,at least u try and live to tell the tale
Hahahaha...
I wonder if a bike shop would even attempt to repair it? Talk about over engineered, it makes overhauling a hub look like child’s play.
From Buenos Aires.......your videos are very goods!!!!
Yep - I've got one and your Video confirms me darkest fears... mine isn't shifting from 1-4 - working fine 5-8 but I ain't going in there - It'll just end up in the Trash...
Thanks...
interesting
I think our fathers and grandfathers were much more clever as we are...
thanks RJ...I've got one sitting around that i was gonna do the same thing...rip it apart to see how it ticks...you just saved me hours and saved me from getting my hands greasy! Thanks keep up the fine work!
Incrédible... Secrets of shimano nexus 8 I hope you can unseambled. After with a schéma it's possible. Thks for you videos... Laetitia de Belgique.... Fans of bike..
This feels like studying the most complex equation of Quantum Field theory by saying:
'Okey, so we start by having an equal sign here. Obviously theres some letters here. We also got, what I think is, a multiplikation here. Looking at this thing we got the digit 2 here...'
an engineering marvel! Magic indeed!
I have a Nexus 7 in my bike that I use for urban commuting. The shifting of gears is very pleasant when it works. Often it doesn't work. The adjustment of the cable on the grip shifter is tricky, and it doesn't provide the accuracy that the gear mechanism requires. The visual aid of aligning yellow lines is difficult to use because of dirt accumulation and scratching on the transparent plastic cover, which are impossible to avoid in everyday use. The problem sounds petty and superficial, but it can prevent the hub from working correctly when the cable gets adjusted wrong. That small but important detail looks like a case of thoughtlessness in design work, like a case of engineers not treating the user interface of their product as a serious design task. I bought the gear hub in 2017, I wonder if Shimano has done anything to fix those issues.
Hello! I have a question: in this hub, does the rack rotate on a freewheel principle (you can turn the pedals backwards)? I will be grateful for your response. greetings.
It's pretty much the same as inside of a car's 'automatic' transmission (which are shifted by computer, and not really automatic)
Please visit this web site: www.sheldonbrown.com/nexus-mech.html. Created by Sheldon "Totally Enclosed" Brown
and revised by John "Interplanetary" Allen - if you want to know more.
Sejt 🇩🇰🇩🇰🇩🇰🏁🏁🏁🇩🇰 utrolig præstation at lave 8 gear på den plads🏁🏁🏁❤️🇩🇰
Can’t understand why bikes dosen’t switch to those things, is more compact practical compared with normal 2x9/10/11 or 1x12. If they made this 8 speed they could made it 10/11/13 too.
I have a problem with the 8 speed and it doesnt goes well in 3 4 5 gear but 1 2 6 7 8 no problem. I greased and it works a bit better but I did not disassembled it like yours. Yes I find it also magic.
Just landed a lady bike with a 4-speed coaster hub, (100 dollar bike!)
Looked like it was from the early 2000's and all original parts. tires still good etc, no rust.
Some rusty screws that need replacing and the chain is in dire need of a cleaning.
Anyways great content!.
And I'm here, thinking how in hell could I repair my Nexus.
#NoFuck1ngWay
Ps: when this guy talks about "this thing" "that stuff" you know Is serious sh1t, but when he says "this works by magic" you know you're done.
Had one on a Trek 7400 and documented all distances travelled. After 12,000kilometres the gearbox failed. Reason: the large ball bearing on the sprocket end fell apart - the riveted sheet metal cage broke. Replaced it with a new gearbox 'cos I luv the transmission, and the bike.
RJ - You look like you're working on a mechanical version of a Rubik's Cube.
Make more Bike rebuild video
Victorian novelist and antiquarian M.R.James would have called this "A Warning To The Curious". I am going to leave my Nexus hub the hell alone.
Goes against the KISS (keep it simple stupid) principle of engineering. Yep, engineering marvel but inferior in most aspects to the simple derailer gears. Thanks for showing us. 😉
If you need to get it back together: Shimano Nexus 8 Speed Reassembly: th-cam.com/video/JNuyvIZvCrs/w-d-xo.html
And if you need more info, see www.sheldonbrown.com/nexus8.shtml
Those Shimano nexus hub are surely amazing and sturdy. I would never venture disassembling one like you did but it was surely interesting to see you doing it. I will leave you alone with my bike! 🤣😏🤣🤣
I just gave my hub oil bath with motor oil 10w40 and gave some grease to bearings during putting hub back together.
Please slow down a bit when making your videos. Usually I use youtube before sleeping, but this pace makes me stressed. Would be much nicer if you slowed down a bit.
On a large white marking board draft in squares in numerical order, reverse engineer placing each item in squares 1 2and 3 etc with video replay I'm sure you could put it back together. Watchmaking and transmission planetary gears are fascination art forms and will remain future tech.
i have rebuild many Nexus 3-7 never 8 those hardly comes in our shop but you can build it back just watch this video backwards ;)
Bloody hell, what's it packed with? It looks like a grease mud emulsion. I wouldn't be surprised to find out it worked just fine after it was cleaned and lubricated with the correct lubricant.
Thats probably why the manufacturing of the shimano IGH is still in Japan and not offshored to Malaysia.
Make the planetary sphere set work in it(now its just the planetary gear-set) opertating in it
Yeah, but what benefit would you have if an planetary sphere set was working in it, well I magine you can start a compass into it and the bike does never has to loose ballance
To track and navigate you headings
To track an install your bike navigator with coördinates to where you are heading
Now that was intense! 😅
It was like watching a guy solving the impossible puzzle.
For those who are interested to learn more about internals of Shimano IGH, Sheldon Brown has a very detailed page with exploded drawings and parts lists: www.sheldonbrown.com/nexus8.shtml
The gear block can be taken apart fully.
You allready had been on the right track.
After remivong the lower bearing shafts.
trurn the upper gear wheels so that the uper bearing shafts moves down to the lower gear wheels.
next you can remove the upper gear wheels.
this allows you to remove the freewheel.
next the lower gear wheels can be removed.
Now the inner gear wheels can be removed too