With precision sealed bearings and cold-forged, aluminum CNC machined cups, Box One Titanium Square Taper bottom brackets are the best option for young BMX racers and other users of three piece cranks in search of performance gains and weight savings. They have hollow, custom titanium-nitride coated titanium spindles and carbon fiber center seals, helping keep the weight down between 185 and 190 grams (well below that of other square taper bottom brackets on the market). Other features include cups that are anodized black with anodized gold inner seals, and a JIS tapered spindle that comes in either 108 or 113 millimeters.