Originally Posted by
ianbasore
Okay, I just bought an inexpensive mountain bike .. while trying to install the rear, I noticed that the freewheel is crooked. When you turn the pedals, the chain slips to the next gear, because the freewheel isn't perfectly straight up and down. Can I fix it so that it's straight again?
It's common for freewheels to wobble a little, to have the sprockets looking like they're out of true. I've never seen it be bad enough to affect shifting.
There is nothing you can do about it, it has to do with how the threads for the freewheel were cut.
Odds are it's not what's giving you trouble anyhow, that sounds more like an issue with derailer adjustment.