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Is there anyway to fix stripped crank arms? Answered

Well I was riding my fixed gear and my right crank arm got stripped. I don't really want to buy a new one but if it's necessary I will get a new set. Is there anyway I can fix it so I don't have to buy a new crank arm set?


Hello Friends,

Most likely it's the crank arm that's stripped since it is usually made of softer and lighter metal. A thread tap can be used to fix the threads if not too much metal has been stripped out. A bike shop should have the correct one.
Otherwise many shops have basically a slightly larger crank puller for addressing this issue, where they chase out a larger set of threads, then use the larger puller to get it off. The crank arm typically goes into the garbage at that point however.

Thanks and Regards,
Umang Kumar

This would be about the only way I know that would work without replacing the crank or arms.

   You would need to install the arm back onto the crank, replace the bolt or nut with loc-tite on the striped threads. 
   Be sure it is on as tight as you can get them. Buy a Roll pin from any auto or hardwear supply.
Don't get one too big, no more than 3/16. You will need to use a drill and a bit sized just less than the roll pin.

Drill into the crank arm untill you get to the crank. At the crank you will have to drill slower as it is a much harder metal.
 Try and drill all the way, take your time and try not to break the drill bit.

Once hole is drilled, take the roll pin with a pair of plyers and hold it to the hole.

With the other hand use a hammer to install the pin.

The square of the crank and the pin will help take the torque, as well keep the arm on.

Hope this helps.


10 years ago

o____o....(has no idea what your talking about..)

. Look at the end of the crank shaft and notice the crack where the shaft and crank mate up. Use the crack for a centerline and drill the 4-5 holes so about half is in the shaft and half is in the crank. Insert tight-fitting dowels into the holes. . Turn the crank assembly 90 degrees from the position above, so that you can drill a hole through the crank, then through the shaft, and then the other side of the crank. Insert tight-fitting dowel.

. If the splines are stripped, you may be able to drill holes around where the pieces mate (parallel to the splines) and insert small dowels. Same basic principle as a Woodruff key.
. Or cross drill (perpendicular to shaft) and pin.
. More fine example of Redneck Engineering. :)