How do you take the freewheel apart on the back of a 20in bicycle wheel?

Answer 1

They're threaded in place. You need a special freewheel puller (park tool sells them, among others.) to remove one and it can be torqued beyond belief. They spin on by pedalling action, so no need to torque that one.

There's a newer freewheel design that sort of mimics the design of MTBs, with a freehub body and a separate sprocket. they need an different approach.

Answer 2

Usually you don't. When they get gritty and start causing trouble some people will try to flush them out and relube them, but most people will simply replace them. Opening one up is rather tricky and will usually require either mad skills with a drift punch or some quite special tools.

Answer 3

If you want it to free coast, then you need a special hub for that, but unless yours is a rare fixie BMX then it should be able to freewheel.

If it doesn't, the easiest way to fix it is to replace the actual freewheel. Not that expensive, but you need a special tool, a freewheel puller.

You can try flushing the freewheel by laying the bike on the side and squirting WD-40 into the F/W, but that is likely only to be a temporary fix.

Answer 4

You need a special too called a freewheel puller, then you simply unscrew it.