chain tension

Mark Alexander

I'm begging you for help.
My chain is continually coming off as much as every 500m and I have tried tightening it. it refuses to stay there by the time I'v tightened the nuts, it's loose and jumps off I am really f***ed off. I bought it to commute and use around town I can't guarantee to get to work. I'm unable to use £700 worth of bike.

fraz167

Hi

Sounds like you need a set of chain tensioners, i can recommend these.

http://www.hubjub.co.uk/mks/mks.htm#ct

Fairly straight forward to use, fit and use to apply tension the chain then tighten track nuts as normal.

I had the same problem

Cheers

Fraser

Cajun

http://www.parktool.com/repair/readhowto.asp?id=26

fraz167

I think the problem is with a single speed or fixed

Cheers
Fraser

meagain

IF it is unshipping within 500 METRES (I'm assuming not MILES), then chain tugs are surely only hiding whatever the real problem IS?

Either the axle is insufficiently tightened. Or the sprocket or (more likely) the ring is not true. Or I suppose the tension is too slack from the outset. I've never used tugs but the only time I've dropped a chain was when I had a warped front ring.

What is the rear drop out? Chromed and Ti have a tendency to allow slippage. What nuts are you using? Proper *%*& track nuts with serrated and moveable faces are best - with a BIG spanner!

redvee

Chainline could also be an issue here. I had similar probs on my SS when I was using a cassette sprocket whilst waiting for the overdue delivery of my SS Spacer kit, this was due to the smaller teeth profile of the sprocket.

rustychisel

agreed. Something else is wrong or incorrectly set up. You haven't said whether the drivechain will not hold tension (wheel slipping), but going for maximum chain tension without addressing the real problem will cause you even greater problems, probably sooner rather than later.

Mark Alexander

right I took it to my LBS. for an opinion and to swap pedals.
I said i'd be back later.... and I was......

Alex (mechanic) had taken the wheel off to take a look and found that the axel was bent :shock: and the barings were well, buggered :?

I needed a new axle, bearings, and he added tensioner's. It's been running smoothly for 15 miles today and what a difference!

rustychisel

Good news. There's a lesson it that for most fixed riders.

BTW: any ideas on how/when the axle was bent?