Another simple check is look at the clearance between the crank chain ring & the chain stay, how many mm is it ? is it too close like 1.mm or about 12.mm away, these little pointers all help to understand if you need to change out the BB.

Also if you have reduced the possible three ring crank-set onto a road bike, on the lowest chain ring possible 22. & the highest gear on the back how close to the chain stay is the chain, do don't want it rubbing across the top.