Slipping chain? hub? freewheel?

[Chuffy]

I have a single speed conversion. I'm using a Wipperman BMX anti-rust chain and an On-One Doofer to tension on a 2006 Ultegra hub. It all looks like this. I've been using these for well over a year now. I was running a 16t sprocket (Gusset) to start with but changed to an 18t over a year ago. I didn't have to alter the chain length for this. All was well until about two months ago when I decided to put the 16t back on. When I reassembled everything the damn thing slipped on every pedal rotation. I couldn't put any pressure on at all. Since then I have:-

• Changed the chain
• Changed the sprocket
• Sprayed GT85 down behind the freehub body

Nothing has worked. All I did was change a 'king sprocket and now my bike won't work.

It's driving me mad. Any ideas please?

Cheers,
Chuffy

 

[Dave5N]

Yes.

Put the 18 back on and learn to pedal.

 

[Chuffy]

Yes.

Put the 18 back on and learn to pedal.

I tried that.

 

[LLB]

Silly Q, is the freewheel bit greased as grease can gum up ratchet mechs when it dries out ?

 

[Chuffy]

Silly Q, is the freewheel bit greased as grease can gum up ratchet mechs when it dries out ?

I don't know whether it's greased (it's never been dismantled) but I have tried squirting GT85 down behind the freehub body just in case.
Didn't work.

 

[LLB]

I don't know whether it's greased (it's never been dismantled) but I have tried squirting GT85 down behind the freehub body just in case.
Didn't work.

I think the only option would be to strip it carefully for cleaning and re greasing.

The problem is that they use grease or heavy oil on gear surfaces to withstand the high pressures whilst still lubing properly. this is why car gearbox oil is so heavy in comparison to engine oil.

If you use a solvent based freeing agent, the risk is that the greased surfaces will have this protective grease film washed away and you are then left with bare metal on bare metal which will wear pretty fast.

If this makes sense

 

[bonj2]

what's that dodgy green, black and transparent plastic thing on your bike?
Maybe you should take that off and it might perform a bit better.
And why have you got such fat wheels on if it's a road bike??

 

[mickle]

New freehub body required I suspect. Although failure after just two years is a little premature.

If it were mine I'd run the chain over the top of the jockey wheel to provide a more chain wrap on the sprocket.

 

[Dave5N]

I tried that.

No need to be tetchy. Just trying to help you.

 

[Chuffy]

Cheers Mickle (and LLB). Sounds like a new freehub is in order. I think the wheels might be a little older than I thought (possibly mid 2005) and they’ve had a hard life (about 8-10,000 miles with me on board and I’m no whippet). I might give the strip-and-clean option first because I’m going to have to remove the axle anyway to fit the new freehub. Joy. I hate fettling hubs.

Mickle - I won't try going over the top of the jockey, the tensioner doesn't work in that direction.

Dave5N – Suggesting that I ‘learn how to pedal’ isn’t helpful advice. I was less tetchy than you deserved.

Bonj – ‘fat wheels’? Those are fairly ordinary Rigida Chrina racing rims with a 25c tyre fitted. But as a ‘serious cyclist’ you would have realised your error, I’m sure. The green and black thing is a novelty hub/spoke lighting device. Makes b’ all difference to the performance of the bike.

 

[MartinC]

New freehub body required I suspect. Although failure after just two years is a little premature.

If it were mine I'd run the chain over the top of the jockey wheel to provide a more chain wrap on the sprocket.

+1

If it's not the freehub then it's 'cos there isn't enough chain wrap on the sprocket. Shorten the chain or get a different tensioner (e.g. the Alfine double jockey wheel one).

 

[briank]

The green 'n' black thing looks pretty cool to me. but what's the Doofer do fer you? And why doesn't Vicky have one?

 

[Chuffy]

+1

If it's not the freehub then it's 'cos there isn't enough chain wrap on the sprocket. Shorten the chain or get a different tensioner (e.g. the Alfine double jockey wheel one).

Chain wrap isn't the issue. I've run that exact set-up for nearly two years with no problems.

 

[tyred]

It almost has to be the freewheel. Either it's gunged up or it's just knackered.

 

[Chuffy]

It almost has to be the freewheel. Either it's gunged up or it's just knackered.

Either way I feel I have a seriously grubby bit of fettling to do very soon....