Bicycle Mechanics - crankarm coming loose

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sshock4
04-25-03, 04:59 PM
my driveside prodigy xc isis crankarm on a raceface srx isis bottom bracket keeps on coming loose, every time i tighten it down real hard, eyt it contualy comes loose. what might the problem be?

thanks

threadend
04-25-03, 05:32 PM
If you rode on it for any time at all with it even slightly loose the clearances of the interface between crankarm and spindle may now beyond acceptable tolerance. I'm not familar with the particular set up you describe, is it splined or tapered? I've had this problem with square taper interfaces before, replacement was the only fix. :(
sshock4
04-25-03, 06:16 PM
yea, thats what im afraid of...

its an isis bb, so its splined, but ity was the lowest model, and now i have the chance to upgrade to a real freeride one

thanks again

Chi
04-25-03, 07:02 PM
Next time you tighten it, use threadlock, the blue stuff. Also, torque it to the correct torque, not super-tight.
MichaelW
04-26-03, 07:01 AM
Chris King is the brains behind ISIS, and has their website lots of mechanically sound advice on torque and fitting.
Scooby Snax
04-26-03, 10:49 AM
what type of bottom bracket are you using? how long have you had it? (miles) and what type of riding are you doing?

Just curious, Ive got a Prodigy XC, ISIS as well.. and I havent put that many miles on it yet
sshock4
04-26-03, 02:39 PM
its a raceface srx bb, it came with a prodigy xc crankset for about 100 dollars. if i just loctited the crank bolt would i be able to keep the thing working for a short period of time until i can make enough money to buy a new bb or crank. also, if i ruined the tolerances, would it be in the bb, or the crank?

thanks
Scooby Snax
04-26-03, 04:22 PM
the spindle on the bottom bracket is Chromoly, so I doubt that it s the BB, the cranks are aluminum, so Id say its the crank arm, sadly I dont think you have a chance in hell of shimming them.

But then you said you wanted a set of Prodigy DH didnt you? Also the SRX BB is suggested for XC only I think.
sshock4
04-26-03, 04:38 PM
hmm...very frustrating....oh well, i guess new cranks come after i replace the pos judy xl that i got for free.

thanks everyone