I have a px10-like bike and it has a cottered crank, it works fine, but I still want to upgrade it.
Does anyone know how I could go about doing that? I know there are allready other threads about this but they didn't help much.
A 70s Peugeot will be French thread; this makes finding replacement BB parts problematic. Phil makes French thread rings for their cartridge BB, and rumor has it these can be used with some Shimano cartridges if you don't want to spend the bucks for the full Phil set-up. Otherwise, a regular square-taper spindle would work with your existing cups -- this would be the cheapest solution. You just need to pick the right length spindle to get the proper chainline with your specific cups and arms.