by Marek » Tue Oct 13, 2009 8:22 pm
Sounds like the indexing, so twiddle is the answer, but as Jon says get a chainwear indicator for the future. They cost next to nothing and can save you a lot of dosh. Just to explain briefly, as you ride more the chain will start to stretch. As the chain stretches is starts to wear down the teeth on your sprockets and your chainring. If you then change your chain after you have worn down the teeth, you will find that it is jumping about all over the place as it does not fit well on the teeth due to them being worn down by the stretched chain. That means to correct the problem you need to get a new cassette and maybe a new chainset. Expensive lesson learnt.
As Jon says, if you check the wear of your chain every couple of weeks with the tool you then know when it is stretched and that this is the time to replace the chain with a new one, saving on you having to replace the rest of your groupset. To avoid going to the LBS, learn how to break and rejoin a chain, can recommend the KMC chains, although those missing link thingies can be a bit tricky to use when they are greasy and dirty.
Cheers
Marek....