Well I have both a Zed and a 210 - never thought to check if the alloy finned/steel drum (ie steel inner alloy outter) will fit the 210 rears - I know they fit on a 510 drum (had some on my old 510 years ago) - given my zed is in bits and I will be going to disc on the rear I could just try one of the zed drums on the 210 and report back later :) but I will be going to disc on the 210 in the future also