I own an old Focus Cyclocross bicycle, which I really want to keep in working order. Unfortunately a while back, the threads on the crank arm retaining nut and spindle wore away, rendering it unusable. As it’s such an old bike, parts are very scarce. I would like to try get the same gearing on it with a new setup (48/34), and I don’t think the bottom bracket needs replacing at all, bearings are fine.
My question is simply what is the best way to go about fixing this? Is it possible to just replace the retaining bolt and spindle itself and keep the old crankset as it was? Or will I have to buy a new crankset altogether to use. I’m aware I will likely have to buy a set just to get the spindle and retaining bolt, but I’d like to keep the original kit on it if possible. I’m not sure if the spindle is pressed into the crank arm or what the setup is. If someone here has experience in this area any help would be greatly appreciated!