A bottom bracket assembly for a bicycle is provided. The bottom bracket assembly may comprise a left bearing, bottom bracket shell and a right bearing. The bottom bracket shell may be threadless and have beveled surfaces for mounting the left and right bearings onto the bottom bracket assembly. A spindle is inserted through the bottom bracket shell. Thereafter, the left and right bearings are preloaded to align the central axis of the spindle to the crankarm rotating axis such that the spindle or left and right crankarms do not wobble and yet do not bind when rotated.