A stripped pedal thread turned a quick fix into a four hour nightmare

A guy brought in a nice road bike with a creaky crank. I figured it was a simple pedal swap, maybe thirty minutes tops. The left pedal came out fine, but the right one was seized solid. I soaked it in penetrating oil, used my longest wrench with a cheater bar, and heard that awful crunch. The aluminum crank arm threads were completely stripped. What should have been a basic job turned into drilling out the old pedal stub, tapping new threads, and installing a helicoil insert. The whole mess took over four hours, and I only charged for one. Has anyone else had a simple pedal removal blow up like that? What's your go-to method for a really stuck pedal before things get ugly?

4 comments

4 Comments

knight.dylan2mo ago

Ever feel like the bike gods just pick one simple job a week to completely curse? My method is basically a slow burn of dread, starting with the longest wrench I own and a prayer. If that doesn't budge it, I wheel the whole frame over to the bench vise so I can really lean into it without the bike moving. Heat from a propane torch on the crank arm, not the pedal axle, has saved me a few times. Past that point, it's just accepting your fate and reaching for the drill.

max_torres448h ago

oh man, that drill moment is brutal. i saw a buddy do this on his old touring bike last year, he had a pedal that absolutely would not budge no matter what. he tried the torch on the crank arm, the biggest cheater bar he could find, even let it soak in pb blaster overnight. finally he just snapped and reached for the drill, but he got a little aggressive with it and bored out the threads on the inside of the crank. ended up having to replace the whole arm, which was a total bummer because it was a nice vintage set.

cole_baker2mo ago

I used to think a big cheater bar was the answer to every stuck pedal. Then I watched a friend snap a crank arm clean off trying that. Your point about heat on the arm itself, @knight.dylan, was a real eye opener for me. It makes sense to expand the metal around the threads instead of cooking the axle. Now my process is almost exactly what you described, right down to the slow dread. The bench vise step is non-negotiable for getting real force on it. I still hate that moment when you have to decide if it's a drill job.

viola_allen2mo ago

Ugh, @cole_baker, that slow dread is the realest part of the job.