Help! Ruined my crankset, need some advice

Hi there everyone. Last week, my bike was in the shop for a few days. While my bike was in the shop I had some grips and pedals arrive that I had ordered 3 months ago. It was a nice day and I was super excited to go out for a rip with the new parts, I didn’t even stop to think that it would matter what side I put my pedals on. 20 minutes into the ride the pedal loosened off and I sheared off the threads inside my crankset. I called around to the sram dealers and I can’t get a new crankset in until January. So far, after talking to 3 bike shops, these are my options. The crankset is a Sram sx eagle powerspline 30T with a truvativ BB, and the bike is a 2020 gt zaskar comp
1- replace the entire groupset- roughly 400-600$
2-wait until January for replacement part, I guess only that crankset fits that BB
3- order new BB and crankset, however pictou county bikes says the only bottom bracket they could order to fit it, is also out of stock and would be mid November and at that point the season is also over
4-??? Any other ideas? I’d hate for it to be the end of my riding season already. Any help is much appreciated

Will a 32t crankset fit my bottom bracket? I should be able to order one of those online

  1. 30T/ 32T is the ring size, on the SX it can be swapped out so not a worry. 32T would be better if you find you don’t use the big sprocket on the cassette too much.

  2. To replace the crank you just need to ensure it’s the same length and made for powerspline.

  3. This happens a lot. You can fix the crank using a helicoil. It won’t be a forever fix but would get you through the rest of the season.

2 Likes

Here’s the fix. Bike shops may not have the kit to fix it but any engineering shop or capable home mechanic should be able to do this.

If getting someone not used to bikes let them know that the non-drive side is counter-threaded.

LBS or Machine shop. It might be repairable.

Awesome, exactly what I need! I’ve tried talking to cyclesmith, sportwheels, bike Pedaler, hub cycle, bike monkey and pictou cycles. None of these shops mentioned doing this. Any recommendations?

No sorry, I’ve not had to do it. A machine shop would have the tools but it’s about knowing the right people or place.

I have successfully repaired damaged threads, but it’s been many years since I worked in a shop and I know that we didn’t replenish the kit after I used them all. Finding a heli-coil kit for the backwards threading locally is probably going to be impossible as that thread is only used in that application. You could try calling around but even if someone could order you a heli-coil kit it’s probably going to be $100 or more for a kit.
Like @JoshM said, a machine shop might be your best option as they may have a heli-coil. Have you tried scrounging the Pinkbike buy and sell for a used crank?

I have not. This just happened last night, so far today has been spent trying to find something new

Actually though, only my drive side crank arm is stripped. The right side should have regular threads, correct? Would it be easier to find a heli-coil? Feel free to let me know if I’m wrong. This whole mountain biking thing has been a big learning curve so far this year

You installed both new pedals, correct? If so, the threads in both crank arms are ruined, even if the non-drive side still seems to hold the pedal in, it won’t last long.

9/16-20 is an odd size that I wouldn’t expect to find anywhere outside of the biking world. I’d be very surprised if you found a machine shop with the taps and heli-coils needed to repair the crankarms.

2 Likes

Correct

The machine shop we use in Burnside has done some magic for us, but it comes at a very hefty price.

@AlexK You are correct, it has regular threads which would slightly increase your changes of finding a heli-coil kit. But like @Jetter said, it’s not a common size.

1 Like

Assuming you mean rods machine shop? I know the owner, and was just chatting with him. He figured it would be roughly 150 for each arm so I kept looking online. I have found a crankset that will work, was just hoping to find something local first to speed up the repair

I use another shop, but that is what I expected price wise from any of the quality shops that would actually do it right. It’s definitely a tough time to be breaking parts. My rear hub let go recently and I was told at least late October before a replacement would be available, luckily I found a solution.

As much as the downtime sucks a used set of cranks is probably your best option.

Did you actually manage to put the pedals on the wrong sides? That would be hard to do. Or did the drive side pedal just come loose and tear out the threads?

Have you tried Long Alley Bicycles in Halifax (Quinpool Road)? I had a cross-threaded BB once, they were able to fix it fairly quickly. Not sure if it’s any different for pedal threads.

1 Like

I ended up ordering a new crank from a site based out of the us. Looks like the cheapest option as the crank I had was only 100. Hopefully express shipping gets it here in time to still ride this year. I greatly appreciate all the suggestions from everyone

Can you post a pic? From what you described it sounds like the issue is the pedal spindle broke leaving the treaded section in the cranks? Is that correct? If so I can’t see how the crank would be damaged. If I am envisioning what happened correctly you could be able to drill out the pedal threaded section and at most retap the threads. Would be easier to offer a solution if you post a pic