Thread started by thegodofthor at 05.7.09 - 9:25 am

So a crank arm on my bike came loose going home over franklin canyon. I was very happy that for that first time I made it up that hill at the start of the canyon. Very unhappy when I had to thank god I had a 8 mm hex on my multi tool.

I've read on the net that once the crank comes loose there is no saving it. but Someone has got to have a answer. On this bike I'd almost be willing to weld it on to keep this from happening again.

Square taper of course.

Thanks

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look at your crank arm... look at the square opening... compare it to the square taper of the bottom bracket... if both parts still fit, and neither part looks worn/rounded, it might simply be the bolt loosening....



adrian
05.7.09 - 9:29 am

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your cranks are toast.


probably not, but maybe. if you over tighten the bolt you'll deform the shape inside the crank, making it difficult to keep the crank arm tight on the spindle.



mmaceda
05.7.09 - 9:30 am

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_iJunes
05.7.09 - 9:34 am

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Your cranks are fine.



Mook
05.7.09 - 11:00 am

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cranksless is the new fixie.



sancho1
05.7.09 - 11:17 am

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interesting post. i had a tough time keeping my mine tight at first... but they seem to have settled in



Candy Cane
05.7.09 - 11:57 am

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if it's a traditional square taper bottom bracket and crankset...I hope you guys are greasing it before you to tighten it!



adrian
05.7.09 - 2:08 pm

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Use loctite on the threads of the bolts. Your problem should stop. If not, then the crank arms are out of round from you riding it loose. I'm betting the loctite will take care of it.



User1
05.7.09 - 2:25 pm

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_iJunes
05.7.09 - 2:27 pm

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I also have a crank question. Today I totally stripped out the threads for the pedal on my right crank. It and the pedal are toast, but I'm wondering what I should replace it with. Also, I'm getting alot of fluctuation in the chain tension as I pedal. Putting on a new crankset didn't fix the problem.



danya
05.7.09 - 4:45 pm

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Grease, grease, grease... It doesn't compress. When you use enough of it on parts, you get a much tighter fit. Use it on everything.

Your chain tension problem is because your chain ring/ cog isn't round, or it's not centered correctly on your crank arm.

Do this: find the tight spot in your chain, then loosen the sprocket bolts. The chain should loosen a bit. Tighten them up and find the tight spot again... do this a million times until the sprocket is centered better. It's a pain in the ass to do but I've had good success with the method in the past.



Mook
05.7.09 - 6:27 pm

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Oh, for cranks, I've always been a fan of Sugino compact doubles. They don't look as nice as fixed gear specific cranks, but you can get the chain line right and there cheaper.



Mook
05.7.09 - 6:31 pm

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Stripped out pedal threads needn't be a big deal, either. With so much material available on a crank arm, I'd think it would be a snap to install a helicoil, which would be stronger than the original threads. If you've messed up the pedal spindle, you can also probably replace the spindle without replacing the entire pedal.



ideasculptor
05.7.09 - 11:42 pm

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