Good morning gentlemen. I had a couple quick questions. Like most other newbies, I'm interested in building a steel road/commuter bike but I need to get some practice under my belt before attempting a build. I work in a shop that builds/restores vintage race cars, so I already have tools and space to do a bike build however our roll cage tubing would make a rather heavy bike. I have an account at an industrial metal supply and they have a great scrap section. From what I have read here 4130 is what most suggest to practice with? What size/wall thickness tubing should I look in to? Another question I had was what is the ID of a head tube that would fit most modern headsets? I'm sure these are way to common questions, but my searches haven't pulled anything for whatever reason.

-Long time newbie lurker