A Gear and Cassette Problem

Question: when I'm riding my bike the chain makes a snapping sound and the peddles jerk and I think it is coming form the rear sprocket, I have a 10 speed and it does it in all gear's any suggestion how to fix it?

Hi Jim,

It could be the chain, but I doubt it as normally the teeth on the cassette wear differently on each sprocket and the chain will run well on some sprockets and jump on others, you say it's bad on all of them. The cassette could be loose on the hub, in which case you need a special cassette tool to tighten the lock ring that holds the cassette to the cassette body onto the wheel.

Those reasons are possible, but I think the cause of your problem, and remember this is a guess without seeing your bike, that it could be the cassette body its self. This is the part that has the free wheel mechanism; this has 2 or 4 little springs that locate a lever into a ratchet. This allows the cassette to rotate only in one direction and if you have been out in the rain then a piece of gravel can get stuck under one of these levers, this makes the cassette jump when you put pressure on the pedals.

You may have to have a new cassette body fitted, but first try running oil into the body from the back and leave the wheel cassette side down and hope that the oil forces the grit or any water that is in there. If this works, great, then you don't need to replace it. Other wise if this still happens you need to take the wheel to the bike shop and get a new cassette body fitted, it's not too expensive, but you need to get it done if you want to be able to ride your bike properly.

If you are in doubt as to what is wrong with your bike then take it to a bike shop, get their mechanic to have a look at it and trust them to fix it properly. It's great to be able to fix your own bike, but some times it's better to get a professional on the job.