I have a bike with a Shimano FC-M560 crankset in the front which I want to replace. I naively bought a Shimano FC-TY301 crankset, thinking that there's norms and that 3-speed cranksets are more or less interchangeable.
Fast forward; the distance between the new crankset's chainrings is larger than the old ones. Since the Shimano Deore LX derailleur doesn't go as close to the seat tube, the chain will rub against the cage when on the smallest chainring.
My question is: How do I select a part that will fit my particular derailleur without relying on the exact series? (The exact components are expensive to get at this point since they're not made anymore).
The service manual here seems to refer to a quantity named stroke, is that the relevant number here?