Like the Box One⢠Chromoly handlebars, Flat Chromoly bars are super stiff and custom made from the highest quality 4130 chrome-molybdenum.They feature a proprietary 13-butted taper from 22.2 ÃÂÂO at the grip area to 31.8 ÃÂÂO across the clamp area.The incredible stiffness of the 31.8 oversize bar improves bike handling while putting more power into your pedal stroke.Flat Chromoly bars, however, have a very flat 3-degree back sweep.