Originally Posted by
Wildwood
Be sure to check the fork and rear triangle for tire clearance if you want wider 650b tires. Many 650a sized bikes were for triathlon and getting a 25 mm tire to fit might be tight. Not an issue on a rando bike, but worth checking.
I think you're confusing 650A with 650C. The latter were used for triathalon. Generally when we see 650A it's on an English 3-speed, and labelled 26x1 3/8.