So - I've fitted a new cassette and chain to the bike and it's indexed pretty well. However - it only runs 'silently' in a few places at the back. In general it's clicking/whirring more noisily than normal.
There *seems* to be something happening at the rear derailleur - the bottom jockey wheel appears to 'pull' which may/may not be causing the noise. Although the jockey wheel teeth are worn it seems to be running smoothly enough.
Any ideas?
TS
Stiff link(s) in chain. Some chains come with a sticky waxy coating which isn't lube. Give it a good wipe and a spot of chain lube. Have a play with the cable tension too.
If the rear mech is jumping about its often cos the ring on the chainset is too worn(usually middle) for the new chain, causing it to suck up round the ring slightly then release. You get a click as the mech bounces back to position. Or your jockey wheels could just be goosed causing the new chain to ride over the teeth and jump about.
Cheers fellas. The chain was coated in some sort of wax so I have degreased and relubed it - no joy. I'll have a look at the problem with the front chainrings now.
Cheers
TS.
It couldn't be anything daft like the chain is too short?
No.
Likely causes IMO:
Indexing is out.
Stiff link (never caused by the factory coating, which is never not a lube, both IME)
the bottom jockey wheel appears to 'pull'
No idea what you mean by this.
Shouldn't be. Best way to check the chainring suck is to ride the bike with someone watching to see if the chain is pulling up, its difficult to see it for yourself and often won't do it on the bike stand as there isn't any tension on the chain. It only has to grab a little to create the clicking noise.
If I turn the pedals and watch the rear derailleur it moves up and down all the time. If I put my finger on it I can feel something pulling it. The indexing seems ok so I'll look for a stiff link.
Thanks again.
Sounds like the B-Screw needs adjusting to pull the jockey wheel off the cassette perhaps?
That sounds more like the new chain and cassette don't like the old jockey wheels. If it was a stiff link it would only happen once every chain rotation, not constant movement you describe. Jamies right make sure the B screw is right, but if it was right before it shouldn't need re-setting unless its a different ratio cassette.
Incidentally, if this:
Although the jockey wheel teeth are worn it seems to be running smoothly enough.
...is the case then why wouldn't you upgrade them at the same time as the cassette/chain? Only about £8 for some decent TACX ones.
Stiff link has sorted most of the problem, jockey wheels next on the list. Are XT (at a massive cost) worth the money over the TACX ones? B screw is fine, same ration cassette.
Thanks for the info.
TS