turn freely.? I pedal the bike and everything is turning, but I'm going nowhere. Shifting into different gears sometimes will engage it, but not usually. Is there some sort of adjustment I can make?
If the rear cassette is turning you need a new freewheel. The pawls on the inside of the freewheel are stuck. You can remove the wheel and lay it down with the gears up and try to get some oil into the pawls to get them loose. You need a special tool to remove the freewheel.
That would likley indicate that the chain is slipping, either due to damaged linkage or a build up of dirt. Check the chain for damage. Ensure that it is well lubricated. If it continues, consider fitting a new chain.
