maintenance schedule tracking software Can't seem to find software to track maintenance i do / is due on bike(s).

I just want to enter when i changed the chain/casette on bike A, then track how many km ive gone with it. Distance could be entered manually or pulled from stava or some such site.
You mention Strava: they do that for you. If you register components and parts of your bike like a chain it will show the mileage from the registering date. It might a bit problematic if you have two sets of wheels (like one for rain and another for sunny days)that you use alternatively.