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!
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.
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)
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
@@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.
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.
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.
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.
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"
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.
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
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 🖖
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.
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.
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!!!
@@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.☺
I just built a winter bike using a Shimano 8 speed hub. I love I got to watch someone else deconstruct one. This video satisfied my basic curiosity. I do most of my own bike repairs and maintenance, but these hubs, no internals for me.
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.
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.
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).
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.
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!
Had this hub laced into an old '85 Raleigh Renegade to replace the 7 cog cluster...ran the bike to about 6k miles and hub developed some play in the body and needed a new rear sprocket....took it to a local bike shop for some work and got it back..never to be the same. Later I went with a Sturmey Archer 8 sp hub, put 10k miles on that with no complaints...so far.
Wow,, does anyone want to try to put this thing back together? I'm looking at an 8 speed internal hub. Can't imagine fixing something like this. Much respect for having this knowledge.
Wore my Nexus 8 out after two and a half years of city riding my Bridgestone belt bike, here in the country that makes them. Popped along to my local bicycle shop, the place where I bought it, and moaned for two or three minutes. They got on to Shimano forthwith, who happily agreed to replace it with a new unit free of charge, even though the one year warranty was out. Bike service is good, here in Japan. Changing a rear tire with a belt and such remains a pain, mind you!
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.
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.
Thank for this video. A few parts on the outside of the hub got loose as I was removing the rear wheel to fix a flat. Your video showed me how they were aligned before I goofed things up!
What a greasy mess, no wonder it wouldn't work. I had one of these on a Bianchi Milano and loved the way it rode. But, I had a flat on the rear and it took me a full day plus lots of busted knuckles, scratched fingers, etc to get it fixed. Great engineering but not for the diy guys like myself. I applaud your courage in taking this apart. I'm fool enough that I would try to get it working again once the grease and dirt were eliminated. Keep up the videos, they have helped me a lot.
I purchased a Gaezelle Tour Popular 8; that has that hub. It also has roller brakes(please do a video on them). The gear set works like a car automatic transmission. But, it's very small and complex like a Swiss watch.
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 (:
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!
RJ, this is why I replace these and don"t even try to fix them. To many moving parts, somebody had a lot of time on there hands to design this! No thanks but interesting. Keep the awesome video's coming!
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.
Couple years ago I was trying to do it in new oil, so got it out, couldn't put up back together by myself then took it to bike repair shop, they gave up, so bought used one, and it is working till this day. Only upgrade I've done, I changed the sprocket for less teeth so a bit quicker.
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.
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...
Dirty hub, cleaning is quite good idea and maybe organizing parts. I found exploded drawing and operational quide. Shimano spare-parts list, I had 2 depending to shaft length, the right one had right number of nuts, so there are many drawings within the same model too. My hub had black grease and it seemed in good condition. That was not problem. My problem was pitted bearings, so I kept transmission as it is, didn't remove safety-clip or that thing holding planet gears. Transmission is serviceable. Sellers manual guides to dip it in transmission oil, not dissassemble, but grease is much easier to apply when gears are dissassembled. It is big operation. And the shifter sleeve is the core of transmission so if you manage to figure out how it works raising pawls and rachets driving gears at each gear, you should find out if there is anything wrong with it, nevertheless it is dirty, the brown grease is contaminated with water or dust or something, oxidated maybe. White grease at hub walls indicates that original grease is white. I got white grease that is official, but there is also black Nexus grease. Dissassembling is easy, you can do it in minutes with one or two hands when it is clean and ready and so is assembling, but now you took the axels it is learning procedure if you make it unit again.
Excellent - I have one that's beginning to grab when freewheeling, so it needs taking apart to clean - your vid's shown the final safe point! Degreasing then plenty of fresh copper *should* be enough!
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! 🤣😏🤣🤣
Thanks for the video, it's great to see what's inside this thing! I have been riding with a nexus 8 hub on one of my bikes for five years now, and it is very reliable overall, especially as I keep the bike outside. One year from new I had the shop I bought it from service the hub as it was "slipping" into a neutral gear (which should of course not exist) when set to gears 5 or 6. When riding this can be dangerous, as you suddenly lose traction. The shop told me they just tightened up the bearings as they were loose, and that indeed fixed the problem. I guess they tightened up what looks to be the bearing cup you see at 1:07 . (I think you can just about see the bearing race from the outside of the housing at 1:13 and then from the inside at 1:24 ). I suppose with the whole stack of internal parts being loose, the pawls were able to slip sideways out of their sockets somehow. There is some great information on Sheldon Brown and from Shimano, but this problem of a loose bearing leading to a sudden neutral gear does not appear to be addressed in any of the "adjustment" information I found on those websites.
I actually dis and reassembled the shimano rollerbrakes on my bike it took me over 10 turns to get them working properly again. watch out for flying springs!
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
Hi, I am currently following a 3 year study for bike mechanic (I am from the Netherlands) and have to learn every single part of multiple gear hubs and how they work. Its a pain... Lol. Try to take apart a 7 speed shimano hub. Its even more complicated, and more moving parts in every gear. Only reason can be so they wear quiker. Anyway, these hubs need a maintenance oil bath with special (blue) oil every now and then. Never use normal grease! Cheers
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.
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
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.
This could be like the 38th minute of a VH1 Behind the Music video--"And then RJ began disassembling bicycle components without bothering to put them back together again." Rut row :)
😨 I guess that's the internal gear trade-off: it's easier to keep it clean, but it's impossible to service it. I like the idea of internal shifting, but after watching this I'm happy with my derailleur systems. Thanks for the video!
I did disassemble one of these 8 speed hubs for a friend about 3 years ago. Only took me like 5-6 tries (2days) to get it back together. Sad thing was that there was too much water damage inside to get it in working order and my friend ended up buying new insides for it. Anyway the whole bike was maintenance nightmare, there was always something wrong with it , especially that EBB bottom bracket that had to be tightened like every other week. Long story shot after that ordeal i have not been a fright to disassemble any bike parts.
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.
Fantastic video & all done live, no rehearsal here guys this is as it happened. Great bit of engineering, it's more complicated than a regular 4 stroke motor... 😂 Thanks for your time RJ..
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
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!.
I have one of these on my bicycle, and yeah, it won't go down into the third, second or first gear. Not really a problem: the fourth gear is light enough, like the first gear on a car. They're finnicky, and I'ld have opted for a three-speed had I known this. Three-speed are good enough for a transport bike.
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.
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!
Thanks for your honesty! I was just wondering ''How is he ever going to remember how all those pieces were assembled'' When you confessed that you probably wouldn't be able to. Haha.
It wasn’t disassembled with a view to reassembly. It’s a very small but similar to an automatic transmission. An auto trans engineer would very carefully lay things down so it could be put back the same way. In my experience do it ten times then you could rip it apart, throw in tub mix it up and reassemble no problem. Just need the opportunity to get familiar with them. But probably there’s no commercial reason to, hourly rate and risk of having to guarantee work I doubt anyone is going to fix; except the curious that like a challenge.
Sheldon Brown had guide for nexus hub servicing and operation. My Nexus 7 was pasman, there you can find how it works shifter sleeve, gear shifting cam, return spring and so. I studied it quite long time before I opened the hub and didn't open it much after all. Reconditioning bearings is my job at the moment, polishing and hardening or covering races with nitric or something a poor man could do.
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.
