Chain Skip…

Benjamin buys his bikes from e-bay; this is great and cheap way to get a bike. This does have problems and one of them is that the gears, chain, cassette and chain rings can be worn.

Question:
I’ve purchased several 70′s Schwinns off eBay and was wondering why (when I put on a new chain), it tends to “jump” while riding on the small rear sprocket. Most of mine are 10-speeds. If I need to buy new freewheels, where’s the best place to buy them?? Thanks!

Hi Benjamin.
Is a fair bet that the sprockets on the cassette are worn, but normally it would skip on one of the middle sprockets, like the 15, 16 or the 17 tooth cogs as these are the most used and the chain tends not to run very well on those gears. The smallest rear sprocket doesn’t normally get as worn as the middle gears and so the new chain would usually run well on it.

Have you checked that the gears are adjusted properly?

First, with the gear cable disconnected, let the gear adjusting screw out so that the gear moves away from the wheel. Then turn the pedals and see if it runs OK. If not tighten the screw as you turn the pedals until the chain runs smoothly. If it never runs smoothly and you turn the screw so far in that the gear changes up to the next gear then the sprocket must be worn and needs replacing.

Secondly, if it does run smoothly then reconnect the gear cable and make sure it is under the correct tension. You do this by changing up from the smallest cog to the second cog. If it does not go up with one click then adjust the cable tightness with the cable adjuster until it changes up smoothly. If it goes too far then you need to loosen the tension by either letting the cable out by loosening the cable bolt, letting the cable out slightly, and then tighten the bolt again. Or, if possible, let some cable out with the cable adjuster until the change is correct and the chain doesn’t go too far towards the next gear. With indexed gears the change from the first cog the second cog must be correct, and then all the others should be correct also.

Where to buy a new sprocket cassette? Well, the local shop is a good place to go in case you have a problem. You could buy one from an internet bike shop, which could be cheaper, depending on the postage and packing charge. If you have a problem then it can get tricky with returns.