Originally Posted by
trons
4130 refers to a material (some certain steel alloy) not tubes. 4130 can be made into tubes, butted or not.
Durr, I just remembered that the rear triangle of a crosscheck (like mine) is straight gauge 4130. Durr. thanks for straightening that out. Well I'd be very surprised if the main triangle of a production road bike was made of the straight gauge stuff, but I guess anything can happen.