does anyone know how to remove the rear gear thing,(the round thing with teeth, that the chain goes around)?

Question

It's on a mountain bike and it seems to have a lock on it.

Answer 1

That thing you mentioned is the cassette. I would recommend you go to a local bike shop and have them remove it, because without them you will have to buy special tools to remove it. You would, I think, need a lockring tool, a chain wip, and maybe a wrench of something else. Hope this helps.

Answer 2

Yes, all mountain bikes have what is called a freewheel plus some sprockets which make up the cassette (aka the whole assembly). To remove it, you need what is called a "cassette removal tool". Basically, it is a socket with groves around the edge that fit the same design of the lock on the cassette. They sell them at most bike shops for about 10-20 dollars.

Answer 3

I'm not sure how a mountain bike works. But if it's like a freewheel on a bmx, then there should be some grooves inside it where it can be loosened and taken off either by using a flat tip screw driver and hammer, or a tool called a prong remover.

If not I suggest asking some one at a bicycle shop but not let them touch the bike unless you don't think you can do it yourself.

Answer 4

You need a special tool called a freewheel remover. Your local bike shop can easily remove the freewheel and clean it or replace it.

Answer 5

There are two types. One is the Free Wheel type. The other is the casset type. Free wheels are cheep.

If you are not sure - go to your local bike shop and thow a couple of quid at them.