Threads repair
 

Have been calling bike shops and none of them will do threads repair. do you know which ones do in NYC?

Which threads? Although most of us cannot point you to a shop, knowing what threads are buggered might help. A water bottle boss thread is much different than a pedal or threaded headset.

pedal attachment. usually i would just replace it but this is Sram Red 22 expensive crank so i try to save to do repair.

Some shops can do crank arm pedal thread repairs with an insert. Some don't, likely most don't. I think your answer will be to call around and ask each shop. I would suggest the older shops first. Andy

do machine shops do it too?

The issue with a machine shop is that they likely don't deal with 9/16" x 20tpi left handed threads often enough to have the inserts on hand. This is a thread spec pretty much bike industry only.

I sense a reluctance to call shops and find out yourself. Am I correct? Andy

Thanks Andy. i didn't realize 20 tpi for 9/16 is not industry standard. BTW, it is for right arm.

Sorry, it was my assumption that it was the LH arm. We see far more LH pedal thread issues then RH ones. Good luck. Andy

I looked up your crank, holy cow! I thought an old DeoreXT crank was hot stuff. It looks like your crank is graphite with a threaded alloy block for the pedal. Just a thought, maybe SRAM does or has recommended vendors for repairs to that crank. Good luck with that.

Hows bad is the damage? If it's just the lead thread you may be able to "chase" it by threading the pedal in from the back side of the crank arm.

Thanks. good idea to contact SRAM to see what they say. and find out the cost for just arm replacement.

it is the entire length of the threads.

Wow, 'someone' must have Schwarzeneggered a pedal install to do that. Most people stop after turning the pedal 1-3 threads
when cross threading, to go all the way is to ignore the 3-4x increased torque needed to cross thread a large thread.
Ability to repair with insert will depend on how big the alloy portion is, as the insert requires 2-3mm larger diameter hole which
is then threaded by the insert, so alloy block must be at least 4-5 mm larger than the 9/16 hole for the pedal.

Mel Kornbluh at Tandems East in New Jersey advertises in his catalogue that he will repair stripped cranks, using Helicoil inserts. You could phone him and see if he can repair yours.

Is this a carbon crank? If so, the threaded part for the pedals might not like being drilled and re-threaded for an insert to be put in it. May just be an insert itself embedded in the carbon.

If your threads are badly damaged, then trying to run a same size tap through it is going to leave too little material to be a decent fix for long.

If it's only damaged at the starting thread or two, then maybe there is hope for just running a tap through it. Or if your pedals have a long enough threaded part to reach all the way through, run them in from the other side and hope they push the damaged part into a better position. Maybe use an old pair.

Machine shops can do helicoil repairs, but may not have the left-hand thread tap and insert required for a non-drive side crank arm. If it's the drive side crank arm, I wouldn't expect a problem.

Are the treads shot or is it the threaded insert itself that's spinning? Happened to me on my TT bike - had to epoxy the insert back in to the crank arm.

Typical of these forums lots of broadcasting not much receiving. Thank you for your excellent response.

...if it helps you, when you call around, this is the threading on a lot of older spark plugs. So places that machine and repair ICE cylinder heads often run into this issue, and might have some 9/16" 20 tpi helicoils on hand, and be willing to install one for you. They do make bicycle specific kits for this, but they run in the$100-120 range, so a lot of places don't bother to buy them. Bicycle co-ops sometimes have them...ours does.

The bicycle repair business suppliers make pedal thread repair kits ...

2 kinds a sleeve threaded on both sides the stripped hole is reamed , then tapped, then the insert goes in

And Helicoil .. a coiled diamond shape steel wire,, similar process..

Your local shop unwilling to do that, don't own or wont buy the tools to do that.

take the crank off ,

mail it to a shop that is willing to do that, owns the tools , etc..


https://cimg3.ibsrv.net/gimg/bikefor...75106e9d8d.png
VAR , France, makes this one..
https://cimg2.ibsrv.net/gimg/bikefor...0b830ba23d.png
helicoil type




...

.
...these guys offer it as an online repair service for $25 9which is pretty cheap), but the mailing costs might kill it for you.

Thanks for totally making my day!

Park has some info as to the repair method

https://www.parktool.com/blog/repair...-kit-procedure

Yup. If there is enough meat on the existing bushing to take a helicoil insert, this repair is easy. If not, you'll have to replace the entire crank arm.

How messed up is it? I would certainly try to tap out the threads first. Other than that, doing a helicoil repair really isn't particularly hard though many shops don't have the kits, but I don't know if the metal insert in those cranks is substantial enough to install a helicoil. There is a zero percent chance SRAM will officially recommend repair, but that doesn't have much relationship to whether it'll work or not.