The Surly Corner Bar is for off-road riders who want to give drop bars a try without swapping out the drivetrain and brake levers on their current mountain setup. Does that make it an economical option for fresh excitement on the trail? Yes, it does. Chromoly steel with custom-butted tubing 46cm, 50cm, and 54cm widths 22.2mm grip diameter 25.4mm clamp diameter One set of 25.4/31.8 x 60mm Problem Solvers shims included