Chain loosens and tightens

When you turn your crank, your chain tightens up the loosens. It can be bad, if so, here is how you could fix it.

Your sprocket is oval in shape, so when you turn, its normal that it does a thing like that.

To corruptly put a chain on with a sprocket like that, do all the preloading etc on the chain when your cranks are in the 'taunt' position.

THats it really. If you put your rear tire and tigthen the chain when it is the cranks are in the 'no taunt' position, then you will end up f'cking your bearing (only a wee bit tho) and seriously stretch your chain.

Yawn. There.

Thank you I'll try to fix it, & Well when I bought the bike I had to replace the cup were you have the bearings sit in it because it busted along with the bearings after awhile of riding it.

Got new spacers, bearings and tensioner?