Many thanks for the responses - the chain is about 18-24 months old and gets about 2 miles a day for 5 days a week on it.

Are there any particular chain cleaner tools/liquids and chain chopping/joining tools you'd recommend? I see plenty of stuff from China on Ebay but you never can tell if they're all much of a muchness or if there's a particular one that is best to use.

And thanks for the Sheldon link - I looked at most but not that page which explains a lot :-)

And also yes I'm on the smaller ring up front - crossing over, which as a temporary measure whilst I get it sorted I will cease to do and take your advice about using other combos but maybe this needs to be a permanent change to my riding practice for the reasons mentioned which make sense. When I come to a stop at the lights I have just tended to stay in the high gear as I'm in a small village with very little traffic so my slow start is rarely a problem. I do take your point though - I used to change down and will start again.

Cheers,

Joe