Originally Posted by
ThermionicScott
650C has a 571mm rim and 650B has a 584mm rim -- in the beginning, 650C actually had the widest tires, since the goal was for all "650" wheels to have the same outside diameter with tires installed.
Exactly so, Hoss:
650A=EA-3="English 26"=26x1-3/8=BSD 590
650B= 26x1-1/2"="Demiballon"=BSD 584
650C= 26x1-3/4"=BSD 571
Convert the inches to metric, add up the numbers, and they are all 650mm-ish in diameter.