Hi everyone,

as a first step into the world of framebuilding I would like to start by welding chromoly threadless stems, in different clamp diameters. I made some research and think I have kinda figured out the tubing selection, but I would need some reassurance.

1. What is generally the O.D of the extension tube? From what I have gathered it seems 1-1/8" is the way to go, independently from handlebar clamp diameter.

2. The most suitable tube I found for a 25.4 handlebar clamp tube was 1-1/8" (28.6mm) O.D, 1.009" (2.62mm) I.D and 0.58" (1.47mm) thickness. My question is, what dimensional tolerance do I have for the handlebar clamp diameter? Could that extra .22mm cause problem? Other option I found was 0.995" (25.27mm) I.D with .065" (1.65mm) thickness.

3. Is .058"-.065" (1.5mm-1.6mm) thick enough for stems? Would .049" (1.25mm) be suitable for the handlebar clamp tube only? I would like to make 26.0 clamp stems too, but the only option I found is 1-1/8" (28.6mm) O.D, 1.0270" (26.08mm) I.D and 0.49" (1.25mm) thickness.

4. Where would one order tubes and binders? I did manage to find tubes on Aircraft Spruce and other websites, and M6x1.0 binders on Nova Cycles Bike Fab Supply (althought I'm not sure they would work for every handlebar clamp diameter?), but I'm still curious if you have other resources.

Thank you for the help