Witness the future of aluminum mountain bikes - on steroids. The time-tested Niner A.I.R. 9 frame is a force to be reckoned with, redesigned with beefy, hydro-formed aluminum tubing. Ride characteristics have been dialed in, adding strength where needed and improving the feel via tube-shaping methods. A tapered head-tube creates the stiffest front end possible, offering increased steering precision to carve a corner or charge down a descent. Press fit BB30 bottom bracket provides additional weight savings. 2 year warranty.