I bought a r300 he 2000 model. I want to verify the size. is it just the distance from the middle of the BB to the middle of the top tube? thanks
Look on the bottom of the bottom bracket–I think it may be stamped on there, if memory serves me.
“56” are the last 2 digits stamped in a long string of #s stamped in the BB of my 56 cm C’dale (1996 year model). So that could be it. But yes, it is center BB to center top tube measured along the seat tube.