Originally Posted by
VintageRide
I tried some searching but somehow have not found the answer. I would like to change the Cinelli 1A 100mm stem ( with the older oval logo ) for a 70mm. There are two on ebay at the moment but I am not sure about diameters. The bike is a late '70's Italian make. The handlebars are 3ttt. Are they 26.4 or 26mm clamp size? I cannot accurately measure the difference. Also, is the insertion diameter 1"? One stem is 22.2mm. Thank you for any assistance.
So what you are saying is you have a Cinelli stem clamped to 3TTT bars and would like a shorter Cinelli stem to replace your existing one? If so, I think you have a 26.0 handlebar with a 26.0 Cinelli stem, so you'll need a 26.0 Cinelli stem if you buy a different one to use with your 3TTT bars. And 22.2mm is the correct insertion diameter.
EDIT: I think it would be worth it to go to a bike shop and have them measure the clamp diameter with calipers, so you know for sure what you have-