mikee":2wuiu22r said:Dunno , I'd say 31.8 with a 26.8/27.2 post
bm0p700f":2olojmoh said:My 1989 is 28.6mm. You should be able to tell by looking at it. If its steel then it will more than likely be 28.6mm. Alu frames will be 31.8mm and only later frames will be 34.9mm as the craze for stiffness took hold.
xerxes":1vpjrwne said:My 1991 Marin uses a 28.6mm front mech.
xerxes":3bu6nsm6 said:Mines a Pine Mountain which has a 27.0mm seat post. With a 30.3mm seat post I'd say it probably needs a 31.8mm front mech.
Do you have a set of calipers, or vernier calipers with which you could measure it? Alternatively use a tailor's tape measure to measure the circumference and divide it by 3.14159 to get the diameter.