August 19, 2005

    Is there a special nut that attaches the pedal spindle onto the axle? I have a mountain bike and recently the pedal shaft became loose from the axle on the left hand side only; I noticed the nut had became loose. No matter how hard I tighten the nut, it just keeps loosening when I cycle hard.

Willie C.

    The pedal axle on the left side of the bike screws into the crank in the opposite direction of most bolts. I mean, to screw it in you rotate the axle nut (known in the biz as the "flats," go figure) counterclockwise as you face the side of the bicycle. The pedal axle kept getting loose because you loosened it, not tightened it.
    Bicycle manufacturers designed left pedals this way so that the act of pedaling forward would not cause a mildly loose pedal to become even looser. Pretty clever, huh?
    When you tighten the axle nut, tighten it only about an eighth of a rotation after the axle nut starts to resist your wrench. Overtightening will make it hard to remove later.

Mr Bike

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