Replacing a crankset, do I also need to replace the bottom bracket? I'm planning on replacing a Shimano FC-510 crankset with an FC-R7000. The bottom bracket has had light use (~2000km) and has no obvious play in it, however the videos I've seen showing removal of these types of cranksets suggest I might need to use a soft mallet to get the axle out. Could the crankset removal process damage the BB bearings, and should I have a replacement BB on hand?
Thanks
No, the process of removing the drive side crank and axle by tapping with a soft-faced mallet will not harm the balls or races in the bearings. The balls and races are hardened and the axle is not a true 'interference' fit in the inner races so you don't have to tap the axle very hard to get it to move.
You can review the Park Tool Repair Help page on two-piece crank removal. If there was a danger of damaging the bearings it would be mentioned and steps to avoid it described.
I will note that I have encountered a FSA PF30 crank that was really tight in a SRAM BB, but you should not have that problem with Shimano cranks in high quality BB bearings.