Gary Fisher / Bontrager crank problem

[GeorgeET]

Ye the UN54 BB is good and well priced, probably a job for the dealer as more special tools are needed.
Do not know what size you need perhaps RobAR can help, or Trevggb. You can email Fisher service.

AS per crankset, why do you want to replace it?? Couse if you do you should also replace the chain and the rear cluster.(not always, but by the book) IMO if it aint broken leave it alone.

[DaveM]

That crank arm is pretty seriously flared. You might be able to keep it on with all the various locktight, lock washer tricks, but doubtful it will make a big difference. What really holds the crank arm on is that it is wedged tight. The bolt is there mainly to force it on, not as much to "hold" it. You should be able to buy a single left crank for pretty cheap. Might not match perfectly, but replacing the arm is the only thing that will really fix it.

It actually would not be unusual for your right crank to be perfectly fine. The left crank undergoes much higher load because it has to transmit all your force through the BB and over to the chain. On the right, a lot of the force goes directly to the chain before it ever reaches the crank arm BB joint. Also, this type of damage occurs from riding a loose crank arm. If an arm is tight, it won't develop this "over time". So if the right was still properly tight, good chance it has no damage. Can't be sure without inspection of course.

[sendittokent]

Hi,
I have a Gary Fisher bike and also I have problems with the left crank arm continually coming loose.
I just recently lost the crank bolt or nut (not too sure of the exact name of the part, excuse my lack of knowledge), however it is the same part as pictured by "tydy" in his photos above (pic three).
Does anybody know where I can get a replacement part?
Many Thanks

[Joe_W]

Any local bike shop should have those (and the hardware store, too). My LBS just gives such stuff to me for free, as I am a regular customer... (and because he's a nice guy and has a ton of those from old bikes)

[sendittokent]

Thanks Joe_W!