Bottom bracket

[dakotaspins]

I recently changed my bottom bracket. since doing so my non crank side bolt for the arm keeps loosening up. Ive tried loctite and it still come loose. i understand why its doing it because when you pedal your spinning it in the direction to loosen a bolt but what can i do to stop it from coming loose on the trail????

 

[ArmyOfNone]

what crank set and bottom bracket?

 

[dakotaspins]

shimano

 

[skaterqwertyuiop]

shimano

Square taper, splined, external bb? Specifics, por favor.

 

[dakotaspins]

square taper

 

[mattybfat]

clearly not torquing crank bolt enough. You also may actually have rounded the square opening on the crank arm which in turn may seem like crank bolt is loosening. If neither then a liberal amount of locktite should hold. What crank bolt are you using steel or Ti?

 

[dakotaspins]

steel. i tighten it as tight as i can get it tried loctite over and over again and it still lossens

 

[soundz]

did u try red loctite? maybe it's a issue with the crank arm hole becoming rounded so it doesn't fit as well .. if there is some play in there when you're torque'ing the crank, it could loosen the bolt over time

either that or you got a defective bottom bracket .. i.e. the spindle on the left side could be too thin

 

[MTBTyler]

Loctite only works if you use 2 drops MAX otherwise it doesnt dry and is actually worse than no loctite

 

[mwlikesbikes]

I'm not an advocate of using loctite on anything bike related. I grease every mating surface before assembly.
What model shimano BB is it? What model cranks? And how old are they?
Like others have said, your crank may be a bit rounded.

 

[fiftyfixe]

Your crank arm bolts should be torqued to thirty pounds. If you have over torqued it you may have deformed the crank arm and you will never be able to get it tight