The photo was from a site that no longer seems to be up. The pedal on the right, measuring at 15.7mm is the same size that the pedal on my indoor spin bike uses and I want to use standard 9/16 threaded pedals instead.
Has anyone come across this size??? Do adapters exist to step up standard 9/16 to 15.7mm?
The pedal on the right seems to have some sort of adapter on it? If you can't find anything bike specific you can get general purpose coils (helicoil i think? ) for for bolting stuff in oversized threads , no idea if that will hold up probably not great if you need to remove them often.
If you can’t find anything bike specific you can get general purpose coils (helicoil i think? ) for for bolting stuff in oversized threads , no idea if that will hold up probably not great if you need to remove them often.
I didn't know if that might work, but thanks for the suggestion. I don't plan to really take the next set of pedals off, unless for servicing, so this might be an option. Never used them before, but know of them.
I think the right pedal has a Unior thread adapter on it. These are used to repair a stripped crank arm. When the 9/16"x20 threads strip out you ream the hole and re-tap it with a 5/8"x24 thread, then and use the adapter to make the pedals fit.
https://uniorusa.com/products/pedal-thread-inserts-10-pieces-set-right-58x24
What this guy said
Very interesting! Now that I see it, I can't unsee it! That's pretty interesting, but I think finding a solution is either going to be too expensive or just not worth the effort. Maybe I'll see if I can just remove the crank arms and put on a standard pair!
You can use one of these to determine the thread type
https://www.amazon.com/ChgImposs-Imperial-Whitworth-Industrial-Measurement/dp/B07J9V9JTK
Unfortunately, this might not be easy to find a solution for. The larger thread size doesn't seem to be a standard bike pedal thread, so finding a specific adapter is probably not possible.
Another solution might be to use some kind of threaded inserts in the cranks (this would probably require drilling the cranks out for a larger thread). But the standard pedal thread of 9/16-20 is not widely used anywhere else, so finding the inserts (let alone a left-handed ones is probably next to impossible.
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