Chain too Long????

paulieb2006

How do you know if your chain is too long? Thought I had a bad front wheel over the last couple of weeks cause every now and again I would get this grinding noise from what I thought was my front wheel. Thought that maybe there was something caught in between the break pads and the rim but no. Brought the wheen back to my LBS and they couldnt find anything wrong with it.
Saturday though, was on a 100k sportive for the local Hospice and it happened again, this time a guy beside me told me that it was my chain. I pedaled on and it happened again after 5-6k and on closer inspection it looked like while freewheeling the chain was off and rubbing off the spokes of the back wheel. I was in the small on the front and small on the back.
This is why I was wondering is the chain too long or does anybody have any ideas? Could it be that it the alignment between front and back rings is off?
Any ideas Please.
Paul

Smokin Joe

To check your chain length, use this -

http://www.machinehead-software.co.uk/b ... hcalc.html

John.T

You should not be using the small / small combination as it has too much chain cross over. It also has the least chain tension.
Quick and easy check on chain length is to put the bike in the big ring and small sprocket. The jockey wheels should be verticaly above one another. This is Shimano's recomended method and the easiest.
If the chain is OK check that the freehub is not seizing up.

System_1

John.T wrote:

You should not be using the small / small combination as it has too much chain cross over. It also has the least chain tension.

I'd agree with that (and big big) but the OP says that the chain is rubbing on the spokes so I'm guessing that actually means smallest gear rather than smallest sprocket, i.e small front and big rear.

If so, it sounds like the rear mech stops need adjusted. Have a look at here. If you take your time it's a fairly easy (if initially slightly confusing) adjustment to make with nothing more than an allen key.

As for chain length the simplest and most effective is the Sheldon method (scroll down, it's there somewhere). I've always set up this way and never had any problems. That link will also give you tips on the derailleur adjustment.

PS: IME bike shops tend to err on the safe side. It's better to have a chain slightly too long than too short. As long as the mechs are set up right a long chain shouldn't be to much of a problem (though it's worth checking).

John.T

He says on small / small. If the chain has not got enough tension then the length at the top can drag into the spokes. The usual cause is a stiff freehub or too long a chain.
If it is stop adjustment the chain will go into the spokes over the big sprocket when he is pedalling, not when freewheeling.