Singlespeed & Fixed Gear - Cranks coming loose?? HELP

Bikeforums.net is a forum about nothing but bikes. Our community can help you find information about hard-to-find and localized information like bicycle tours, specialties like where in your area to have your recumbent bike serviced, or what are the best bicycle tires and seats for the activities you use your bike for.



PDA

View Full Version : Cranks coming loose?? HELP

ty151
08-21-09, 09:51 AM
So i have searched around a little bit and spent some time removing and reinstalling my cranks and bottom bracket.

The frame is a Soma Rush and the cranks are Sugino and the sprocket is Sugino messenger. Everytime i ride, the cranks will come loose and if i rode far enough, would probably come all the way off. I have to bring the allen wrench with me if im riding more than a mile cause they become loose fairly quick. I have tried a little bit of locktite and stuff but it doesnt seem to work.

Any ideas???? Any replies are greatly appreciated. Thanks in advance.

-Tyler

ianjk
08-21-09, 09:53 AM
Probably need new cranks. Once they come loose, the tapers will get marred/deformed and not seat properly, hence the tendency to continue to loosen up.
Yo!
08-21-09, 10:12 AM
What taper is your spindle? How old are your cranks? Chainring type is irrelevant for this issue, but remember, installing and removing a square taper crank frequently will enlarge the hole ever so slightly.

As far as spindles, A JIS taper spindle will fit an ISO crank arm, but sit about 4.5mm out. Conversely, an ISO taper spindle with a JIS crankarm will sit 4.5mm closer, and sometimes the taper will never allow you to fully tighten the crank arm before the bolt bottoms out.

If you're using messenger crank arms, those are JIS taper. Make sure you don't have an ISO taper spindle in your current bb.