Non-drivetrain side crank arm is all of a sudden all rusty and shaking. Drivetrain side looks fine. Do I need to replace the bottom bracket & crank arm?
by topotronic
Non-drivetrain side crank arm is all of a sudden all rusty and shaking. Drivetrain side looks fine. Do I need to replace the bottom bracket & crank arm?
by topotronic
4 Comments
Bearings are done.
The crank arm itself is just a separate part. Apart from being rusty its still ok to use.
Take it apart and look at the crank arm. If its worn, replace.
Based on the look of the BB I would assume new bracket is in order and thats likely the only issue.
The rust is from the blown bearing, crank arm is aluminum and cannot rust. Replace the bottom bracket
Does the right crankarm also move/shake when you move the left crankarm like that?
If yes, then your bottom bracket failed and needs replacement.
If no, then your left crankarm bolt is loose. If you’re lucky, tightening to the proper torque it will permantently fix it. But if the left crankarm’s interface to the spindle is compromised, it’ll be only a temporary fix, and it’ll come loose again.