Sunday, September 14, 2008

An Old Bike Project is Never "Finished"

Looks like I spoke too soon. After riding the Runwell around a bit, it has developed a loud clunk in the right crank arm, the result of a mangled crank cotter that I just can't get tight enough anymore. Fortunately, I can order new cotters in the right size from Harris Cyclery, but it puts the bike out of commission for another week, at least, and forces me to confront yet another somewhat-dreaded DIY repair. I'd like to hear from anyone who has extracted/installed their own crank cotters without a cotter pin press. I've heard about bent pins, ruined cranks, etc., but I'd like to hear some happy stories with good endings. Anybody?


  1. Honestly Thom, it isn't all that bad.
    Just use a lot of penetrating oil on it beforehand, support the crank on a block of wood or something - perhaps even using a bit of brass or copper pipe (something softer than the crank) to give a hole for the cotter pin to fall into. Then either use a hardwood block as a "drift" OR drill or punch a small recess into the end of the old cotter pin and just knock it through with a centre/nail punch.
    You may need to hit it hard! The only danger might be inadvertantly whacking the frame...just use a longer drift or punch. Or use a soft mallet instead of a hammer...


  2. Anonymous is right. You may inherently be afraid of its old British-ness, but the work you've done already is way harde tham changing cotter pins.

    Hammer, wood block and cushioning underneath to prevent scratches...Dont' be afraid to really hit it, or else you may not get it out.

  3. Cool, thanks guys. What about heating the cranks? I don't have a torch, but would a bit of boiling water work? Or would that be counter-productive by "softening" the pins as well? I've set some penetrating oil to work for a few days--I'd like to cover as many bases as possible so there's no trouble.