Gear Slip

ALaPlage

Can anyone advise? 80 miler today: FIley-Scarborough-Pickering via Yedingham-Whitby-Scarborough-Filey for those that know the area. I have two problems - first changing from the 50 ring on the front to the 34 ring occassionaly has the chain dropping off the front altogether. What do I need to adjust to stop this happening?

Secondly on the way back from Whitby the chain kept slipping when on the middle rings of the rear cassette. Fine on the 28 tooth and 24 tooth and also at the other end on the 11, 12 and 13 but on the 14, 15,17,19 and 21 teeth rings it was slipping. Cassette is fairly new and no signs of shearing or wear on the teeth. Friend thinks it has something to do with cable tension but not sure. Where do I start or is this a job for the LBS?

Any thought/advice appreciated.

sungod

i) adjust the limit stop screw, usually the upper/outer screw on the front mech

ii) cassette new, is the chain new too? if not then change it quick otherwise old chain + new cassette == accelerated wear. could also be adjustment, the makers' websites have detailed instructions for their equipment, for instance shimano has all the info at http://techdocs.shimano.com

shmo

Hmm if it's indexing fine at the top and bottom of the cassette then the tension alone shouldn't really be the culprit.

A corroding cable inner or outer could cause the indexing problem. If it's old then pull out the cable and replace if it's frayed or rusting. Also check the condition of the outer particularly the bit that goes to the rear derailleur and if it looks ok then blast some TF2 or other lubricant through it otherwise replace that too.

Cable only costs a few quid so that's the first thing I'd do anyway.