Stripped a crank bolt and the fix took 4 hours

I was swapping cranks on a Trek 520 last Saturday and the non-drive side bolt stripped before I even got it torqued down. Ended up having to drill it out with a left-hand bit set I bought on clearance, then chase the threads. Has anyone else had a simple crank swap turn into an all day project?

3 comments

3 Comments

williamd701mo ago

Dude I literally just watched a GCN video about this exact thing happening to some guy on a tour. They said using a torque wrench on crank bolts is a total waste of time and just causes problems like this. Hand tight plus a good amount of arm muscle is all you need apparently.

hugo_coleman2811d ago

Nah man "hand tight plus a good amount of arm muscle" sounds like a recipe for stripping stuff out honestly. I get what you're saying about the GCN video but I've seen so many people wreck their bolts by just cranking on them with no feel for what the actual spec should be. Torque wrenches can definitely be overkill for some things but on crank bolts I'd rather be safe than sorry after dealing with a loose crank on a long ride once. That experience sucked and I never want to repeat it. So yeah I'm with you on the frustration but I think the video might be oversimplifying it a bit.

claire9991mo agoMost Upvoted

lol I actually had a very similar issue a few years back. Real talk though, the real problem might not be using a torque wrench but the crank arm itself. Some cheaper cranks have soft alloy that just gives up before you get anywhere near the spec. Had an old Shimano crank do the same thing to me, turned out the threads in the arm were basically garbage from the factory. Took me forever to figure that out after I already wrecked the bolt.