Shimano Nexus 8 Speed Hub SG-R31 Disassembly and Assembly

Disassembly and reassembly of Nexus SG-R31 internal gear hub.
I'm not a bike mechanic so please also read the manual for your hub.
Link to great video using similar nexus hub:
• Shimano Nexus 8 Speed ...

[@solaroweder3707]

Thank you for this detailed teardown. I'm using two of these transmissions in turn on my bike. Both of them have been in use for about 20.000 km. It's videos like this one that enable me to continue maintaining them and keep them running.

[@marius8349]

These hubs are amazing, I've opened mine from pure curiosity and the clutch spring came off on me, it took me almost three days to figure out everything, of course with help from RUclips, mine is a Nexus 5 speeds E bike design hub on a Pegasus bike with Bosch motor and Gates belt transmission. Nice job with your video, it helps a lot of people.

[@jbaccanalia]

Man! Shimano should be paying you for this brilliant tear down. Great analysis of every part. It's no longer a mystery. The string trick is going in my repertoire. Keeping order and directionality, It's way better than a container.

[@namdarbolour9890]

Excellent video and analysis, thanks! To press the right side cone down, I've found you don't need the Shimano special tool, or even your socket idea (which is brilliant). Just use the locknut to drive down the cone (with the 3 parts under it) down the axle, until the special washer under the locknut bottoms out against the shoulder on the axle. This is what you're doing anyway during the final tightening of the locknut, and what locates the cone to its designated location on the hub. (The left cone does the bearing adjustment.) Just make sure the right cone is square (not cocked) on the axle before starting to crank down on the locknut. Also, make sure the two fingers of the shift collar are positioned in the space (circular slot) between the axle and the cone, and that as you bottom out, they are also positioned in the slot area of the star washer that attaches to the cassette joint, else interference will keep it from bottoming out. FYI, if you use the special tool, it doesn't drive the cone down all the way, rather leaves the last bit to be pressed by the locknut I speak of. You can see this final press-fit-by-the-locknut in other videos on RUclips because they have to use a wrench for about the last 2 turns to bottom out the cone! Hope this helps. A video would help, I know, but I have to learn how. Again, thanks for taking the time to share your knowledge.

[@donaldmacpherson8308]

Thanks! Without this video i could never have managed the hub assembly.

[@WalkerChris13]

This really helped me with my hub assembly. You're great!

[@ChrisBliss-ln1cq]

Thanks so much! Brilliant. You can use a drill chuck, detached of course, to manipulate the spring ,by clamping the end tab in the jaws. Easier to handle plus won't damage it. Enter here only those with the patience of Jobe! 😂

[@rhulzinga67]

Thanks a lot. Now I’m prepared for my own nexus adventure 😃

[@RuolfGoegemeente]

Thanks, very helpfull video, and good quality (both sound, sharpness and light). Certain parts I've replayed many times ...

[@SuperHyperExtra]

Excellent. Very helpful. Thanks!

[@silverchannel8582]

Thanks, helped a bunch!

[@Siroitin]

So, I have to disassemble the whole thing to change ball retainers?

[@robertnewell-dj8un]

I’m in the middle of taking apart my Alfine hub which was slipping but the shift key has legs on both sides! it’s not the same 🤦‍♂️

[@philipoconnor8222]

Great video, thanks. The shift lever on mine is quite loose. you mention this, but mine looks significantly looser. Any comment

[@ThienTran-ly9fi]

What kindnof oil do you use and what kind of grease do you use? Thanks a bunch