I was at the bikepark the other day when my left pedal started wobbling and then it completely ripped out the threads from my Sram SX Eagle PowerSpline crank. And this isn't the first time this has happened. It happened about a year ago the exact same way with the exact same cranks and exact same pedals, so I ordered the same cranks again, since I thought I probably cross-threaded the pedal. While installing the pedals into the new cranks I made 100% sure I wasn't cross-treading them and I vividly remember that there was virtually no resistance while screwing them in, so there's no way I could've cross-threaded them. And I don't think I push my bike THAT hard… Oh yeah, and both of the times that this happened it was only the left pedal, the right one is absolutely perfectly fine. Both of the cranks lasted about a year and then this happened. I was thinking if the thread on the left pedal is weird or anything, but it looks fine to me. I also tested it on an old Sr Suntour crank I have lying around and I tried cross-threading and overtightening it on purpose, but I just couldn't replicate it, which leads me to think it's the cranks. What do you think I should do with this?
by Bitter_Love1724
7 Comments
Don’t be offended but this is reddit so one doesn’t know who is who. Did you check the threading before putting them on ?
Left pedal tightens to the left, Right pedal tightens to the right. Standing, facing the bike, pedal closest to you? They are threaded opposite to each other.
https://www.parktool.com/en-us/blog/repair-help/pedal-installation-and-removal
Looks like it wasn’t tight enough… Pedals require a lot of torque to be appropriately tightened. I’ve never pulled threads out from “over tightening”, they can take a lot of torque. I see this happen when a short Allen key is used. You’ll want to make sure that they are proper tight but need leverage to get there. Get a longer Allen key or put something like a pipe or handlebar onto the end of it. Don’t forget the grease!
It’s possible to repair that crank with a Helicoil insert, but finding a shop with the tools, supplies, and willingness to do it is the problem.
It is a pretty common fix and most shops should have the kit.
They drill and tap an oversized hole then install the appropriated threaded insert.
You could try a threaded insert. It’s a pain in the ass. Hard to find reverse threaded inserts and they’re kind of pricey to begin with. Honestly I’ve done this and if this was just one side I would say you didn’t cross thread them now. Correct me if I’m wrong but both pedals got stripped out. That sounds like they got cross-threaded. I’ve never seen any other reason for both at least.
Like I said, park makes a kit but it’s a pricey kit and I don’t work on bikes. At least this problem on a bike often enough to not just buy another crank set. Why I buy cheap crank sets 🤣 like I said, this happens to all of us pedal strikes are a bitch
Happened to me with an old school Suntour XR17 crankset not to long ago. I am a big dude so I figured it was just from putting a lot of strain on the pedals over time and it eventually just gave out.
Replaced it with an XT FC-M8100 and converted to a hollowtech bottom bracket. No issues since, knock on wood.
New cranks, looks like the pedal R&L were switched