Bicycle Mechanics - Cranks keep coming loose
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08-19-02, 05:24 PM
My left crank keeps coming loose, no matter how hard i tighten it. The aluminium crank has been sort of mis-shaped a little (where it fits onto the BB axle) - is their a way to fix this??
Can you buy a single crank?
A beer can shim might be a trmporary fix,but the crank arm is trashed.
08-19-02, 11:05 PM
your bottom bracket could also be toast (the flat tapers). make sure you don't overtighten the cranks on your next set. save up man...get the new splined setup if you can afford it.
John, you can buy just a single arm. Either right or left. Your LBS can help you with that.
If the hole in the crank is the least bit misshapen, no amount of tightening will keep it on there. Is the crank held on by a bolt or nut? Bolts are better! Also, once you get a new left crank, check the bolt or nut the first time you hear the slightest creak. That creak is your first and only warning. Then the creak stops and the arm falls off!
Go get it fixed right. I shouldn't be more than $20 out the door!
08-22-02, 07:42 AM
Boy did I learn that lesson the hard way...
But I put the beercan/potato-chip bag shim method to good use on my fixed gear. It took some trial and error, but it works fine now
This is advice for everybody:
When you feel your crank getting loose, stop riding immediately.
Usually, the first indication of your crank arm coming loose is that the pedal starts to squirm as you pedal.
If your crank arm is loose, it only takes a couple of revolutions to ruin the crank arm.
Someone mentioned using strips of beer can for a shim. I found that if your damage is so great that you can use a beer can for a shim, the crank arm is shot. Get a new one.
I HAVE used stips of aluminum foil for shims on stripped cranks. This works pretty well, but it is probably due to the fact that the damage was minimal in the first place.
08-22-02, 03:26 PM
I say just grit your teeth and fork out the cash for a new set of cranks and bb. get a splined set. I used to go through cranks and bb's all the time because they rounded out. I got a set from AC componets that were not supposed to do it. The guys at AC said I put them together wrong, ha. So they gave me a new set for free and installed them for me. They rounded out. They said that pair was defective gave me another set and wouldent ya know, it happend again. They gave me a free set again. Since then I have switched to KookaKranks and they are finally starting to go( after 2 hard years. Next set will be splined on all 3 bikes.
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