What is Reddit's opinion of 9/16-20 Right & Left Hand Thread Tap HSS 9/16'' - 20 TPI for Bike Crank Repair?

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Either have to replace the crank or arm or retread it with this

https://www.amazon.com/20-Right-Left-Hand-Thread/dp/B075N48H1S/ref=mp_s_a_1_1_sspa?crid=29FPQG7EVW7PY&keywords=bike+pedal+tap&qid=1667794991&sprefix=bike+pedal+tap%2Caps%2C259&sr=8-1-spons&psc=1

I had pretty much the same issue with my left pedal/crank arm back in December. I bought one of these thread tools off Amazon and re-tapped the threads. The comments on Amazon are very helpful (about using compressed air, some lubrication, cleaning up the metal shards, etc.) on how to use the tool. I was able to successfully rethread the crank arm and re-insert the pedal (this assumes your pedal threads haven't been damaged). You will need a 15mm wrench to re-tighten the pedal. Good luck!

No, the pedals are fine. Threads on the pedal are steel. Threads on the crank are aluminum. The aluminum threads on the outside of that pedal are cross-threaded.

If you want to DIY, you'd need to get a left handed tap in 9/16-20 size and chase in the threads from the back side.

https://www.amazon.com/dp/B075N48H1S?_encoding=UTF8&psc=1&ref_=cm_sw_r_cp_ud_dp_SQ84861FGZ1Z5HRKSMPW

A shop probably has these and could do it for you in just a couple of minutes.

Someone on this sub told me about this and it worked!

I bought this pedal tap. Re-tapped the left pedal again...three weeks later no issues.

There's a chance you could chase the threads with this. The non-drive side often gets FUBAR'd because people don't realize it is reverse threaded.