chain tension...

[october]

again with the nexus 3 hub...

chain is tight in one crank position, but really loose in another.

as you turn the cranks the chain gets loose then tight etc.

what causes this?
how to fix?

thanks, oct.

 

[stephen]

Don't know why. I noticed that happens on 3 of my bikes!

 

[user 135]

Try changing the sprocket up front. Sometimes they are not the best made and have some eliptical shape (biopace).

 

[Markm]

bent sprocket or twisted chain...?

 

[Schwinnspastic]

I see this all the time they just dont make parts like they use to.....I have found that the center hole in the crank sprocket is usually
the cause of the problem either drilled off center , egged out or too large for the crank that it wont center itself..I usually find another
sprocket is the cure....something to keep in mind ...if its not causing the chain to come off I will let a little "out of roundness" slide and
adjust the chain in the tight spot ...a little loosness is ok but too tight will wear out the rear hub.
my 2 cents

 

[october]

thanks guys...

i will check out the sprocket...

oct.