A Cassette Problem

Dave has one of those problems we all get occasionally, usually during or after the bad weather of the winter, his cassette is just spinning round and not making the wheel turn. There are a couple of possible causes.

Question:
My cassette is just spinning is this the hub or cassette that is broken?

Hi Dave.

Your problem is fairly common, especially after or during bad weather as water and bits of grit get in to the workings of the freewheel, here are the three possibilities:

First and probably the most probable reason is that the freewheel part of the hub is either worn out, broken or has some water and grit stopping the pawls from engaging. Try taking the wheel out and run oil into the cassette body and leave it for a while; this may wash out the water and any grit that is in there.

If the freewheel part is broken or worn out then you need to change the Cassette body, this is the part that the cassette slides onto and has the little levers that engage to allow you to turn the wheel forward. This is a job for a bike shop or someone who knows what they are doing, plus they need the proper tools. This part (the cassette body) is held to the hub body with a hollow bolt that needs a large Allen key to remove, depending on which hub you have.

Another possibility could be that the cassette body is worn, not the internal parts, but the grooves that the cassette locates on to. If this is the case then the cassette body will need to be replaced, like above.

The cheapest of all the problems and the least likely is that the face plate that holds the cassette on to the cassette body is loose and the cassette is not being held tight. This is very unlikely as the cassette will still turn the wheel but will be a bit sloppy. For this problem you need a special tool to tighten it.

Take the wheel to the bike shop and they will replace the cassette body, it’s not too expensive and it sounds like you need it fixing. You shouldn’t need to replace the cassette its self as it shouldn’t be worn, just the internal workings of the cassette body. Whatever you do don’t try to disassemble the cassette body as it has lots of very small ball bearings and springs, they fly out and are very difficult to replace.

Good luck!