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  1. #1
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    couple questions

    Hello im about 370 lbs , and just started riding a fixed gear mtb conversion i just got done putting together . Im having a problem with my left crank arm nut loosening while riding ,the arm has actually fallen completely off once .What would be the solution to htis problem ?And ,can you put a 26x2.0 tire on a 26x1.5 rim , or a 26x1.5 tire on a 26x2.0 rim? your help would be greatly appreciated . thank you

  2. #2
    The Site Administrator: Currently at home recovering from a couple of strokes,please contact my assistnt admins for forum issues Tom Stormcrowe's Avatar
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    Quote Originally Posted by shotgunshoe View Post
    Hello im about 370 lbs , and just started riding a fixed gear mtb conversion i just got done putting together . Im having a problem with my left crank arm nut loosening while riding ,the arm has actually fallen completely off once .What would be the solution to htis problem ?And ,can you put a 26x2.0 tire on a 26x1.5 rim , or a 26x1.5 tire on a 26x2.0 rim? your help would be greatly appreciated . thank you
    26X2 tire will go on a 26X1.5 rim nicely.

    Crank nut: Proper torque and Loctite Blue on the threads should do it and you won't need a torch to remove either. Confirm this in the mechanics forum to be sure though.
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  3. #3
    Air
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    Destroyer of Wheels Air's Avatar
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    It's possible the arm has been worn in the middle which is why it's unwinding.

  4. #4
    Senior Member Bill Kapaun's Avatar
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    Are these square taper or?
    There are 2 standards used in sq. taper cranks, with the angle of the taper slightly different.
    IF it's a used crank, it may have been "messed up" before you got it.
    Typical torque, IIRC, is 30 FT-LB. You might just go ahead and exceed that some if 30 isn't doing the job. A 24x series loctite should do the job. That would let you know if the problem is the bolt/nut backing off, or if the taper/spline is damaged.
    Fixed gear! Your knees are a lot better than mine!

  5. #5
    Senior Member c_m_shooter's Avatar
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    Your crank arm is probably shot. Replace it and make sure you retorque the new one after the first few rides.

  6. #6
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    i feel like the nut isnt getting enough of the thread , i got the hammer out and tried to force the arm in as far as possible but it would still loosen after about 15 mins orf riding . The arm has got a sguare cut and it seems like the receiver tapers so im assuming thats what it is....

  7. #7
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    oh yeah and the arms are brand new bulletproof

  8. #8
    Senior Member Bill Kapaun's Avatar
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    After tightening, ride a couple blocks and retighten. Repeat at (hopefully) increasingly longer intervals, until they seem to NOT loosen anymore.
    I was doing some crank swapping a little while back and just carried the wrench with me, while running errands. It took 3-4 "repeats" until they were tight enough to stay.

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