How do you replace free wheel on a bicycle?

Answer 1

First off there's a difference between freewheels and freehubs, and they're not dealt with the same way. Replacing a freewheel begins by getting the wheel off the frame then removing the axle nuts. Then you need to identify the right tool bit for the job. If it's a Shimano freewheel it's a thingy with external splines, other brands use a thingy with two prongs. Clamp tool bit in a vise, put wheel over tool, use rim for leverage to unscrew. Make sure to turn in the right direction(normal thread) and be warned that it might be quite badly stuck. Once it's off, bring the sad remains to your local bike shop and ask him to sell you a new one - it should screw right on. Don't forget to replace the chain while you're at it, as chain and sprocket wear in together and should be replaced together.