Shimano Nexus 8 speed hub... Help!

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 MisterPiggy 22 May 2020

Good evening,

Bit of a long shot, but here goes:

I picked up from the rubbish last night ('big rubbish' disposal in our area; the council picks up the following morning) a great looking bicycle: Trek Soho. It's got an 8  speed Shimano Nexus hub gear running off a carbon fibre drive belt.

When I pedal, the rear sprocket goes around and the bicycle doesn't move. I've spent the afternoon with Google trying to identify the problem. About the only consistent advice I find is: "Don't bother, those things are too complex and life is too short - just buy a new hub gear."

I could do that - a new hub is about £110, but I'd rather fix it if I knew what was wrong...

Anyone have any thoughts?

All the best, julian

 elsewhere 22 May 2020
In reply to MisterPiggy:

I've heard it's finicky if the cable is sticking so check/lubricate/adjust the shifter/cable. 

Sounds like a great commuter for the cost of a hub or used wheel from ebay.

 ogreville 22 May 2020
In reply to MisterPiggy:

Just go for it. Couple of hours should do it if you're at all technically minder and keep a track of the parts. Film yourself with your phone when disassembling so that you can play it back when reassembling.  
Did something similar with a sturmey archer 5 speed and it wasnt too bad. Check out youtube. Few videos on there.

OP MisterPiggy 22 May 2020
In reply to ogreville:

Thanks for the replies and encouragement. I'll do just that, have a go and film the progress so I can fit it all back together again. Along with the tools, I'm ordering a new hub gear, so if I mess up the repair, I'll just replace it. And if I can fix it, I'll return the new hub.

Thanks again, have a great weekend.

 mike123 23 May 2020
In reply to MisterPiggy: no advice to offer  re fixing the hub (!) , but I've been pondering 8 speed hubs recently and so just googled that bike . What a great looking bike for a commuter . According to Evans bikes it was from 10 years ago  . I wonder why bike like this didn't catch on ? When did disc brakes become common on anything other than mtb s , Five years ago ? Belt drive . Why not ? Seems like an obvious advance from a chain . Anyway good luck with the rebuild , I'd be interested to see pictures and or videos . Could you update this thread if you have chance .  I'd be pleasantly  if it wasn't complicated , isn't the idea that they are very low or no maintence ?

I remember many years ago meeting a guy on a tour and spending the day riding and the  evening in the pub  with him . He said that he needed to know how everything on his bike worked so had taken a early thumb shifter apart on his bench at work . after much puzzling he had concluded it was impossible to put it back together . It transpired he was in the RAF and his job was stripping down and rebuilding the engines on tornadoes. 

 TobyA 23 May 2020
In reply to MisterPiggy:

Again sorry no advice on the hub as I've never dealt with hub gears, but Trek Sohos were super trendy a few years ago. But this was just in the rubbish? Could it have been nicked?

Good luck.

 mike123 23 May 2020
In reply to mike123: To give him the credit due I should add that the RAF chap actually said that the the thumb shifter could only be put together at work bench in a shmano workshop with several very specialist tools . He thought he could probably make the tools but the time required was just silly. This may well be the case with your hub . Hence no YouTube footage ? 

 mike123 23 May 2020
In reply to MisterPiggy: have you seen this :

youtube.com/watch?v=JNuyvIZvCrs&

 elsewhere 23 May 2020
In reply to mike123:

Belt drive - you can't split the belt like you can a chain so you need to be able to split the frame to change the belt.

Split frame not a popular idea.

Just googled, it seems split belt has been invented.

https://www.veercycle.com/

 elsewhere 23 May 2020
In reply to MisterPiggy:

Does it have hub brakes too?

 mike123 23 May 2020
In reply to MisterPiggy: spoiler , you might want to go to 29 minutes before watching the whole thing .  Also,  if you decide you don't want to have a go , can I have it please ?  I'm fascinated by this .  Just the thing for a rainy windy Saturday next winter .  ill be busy on Sunday as I'm  Assuming  Eden rock will be open by then. 

OP MisterPiggy 23 May 2020
In reply to TobyA:

Not nicked; we passed the owner's house as he put it out on the kerbside. He told us how the gears were knacked, and he'd had a go at fixing it, and just gave up.

It's a nice machine, everything else on it works fine, paints perfect, wheels true, discs true and unscratched etc etc. Just the busted hub.

Yup, since there's interest in the topic, I'll post a recap when I've finished the rebuild. Though it might be a couple of weeks.

Hope you're all having a good weekend.

j

PS in the same scrounge-around, I picked up some Burton snowboarding boots, and a wrought iron bench with table. Just need to replace the wooden slats. I think I might have been a Womble in a previous life. 😀

 TobyA 23 May 2020
In reply to MisterPiggy:

I remember the drive belts seemed a really appealing idea, particularly on a bike that you ride with normal clothes on - short commuting/shopping trips etc. but I don't think they have really taken off. 

It'll be interesting to hear how you find it once you've got the gears fixed. Re: wombling - people are odd throwing things like that out, I bet even if you had to buy a new wheel built around a new Nexus hub, it wouldn't be super expensive. Or paying for someone in a bike shop to fix it for you... ?

 Mike-W-99 24 May 2020
In reply to MisterPiggy:

I had one of these. Gears went after 1 year, got them replaced and 1 year later they went again. Gave bike away after dismantling the hub and putting it all back together with no luck.

Prone to water ingress I think was the problem, may have been resolved in newer models?


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