EX 511 For the fastest EWS riders, a 30 mm welded enduro rim. Enduro may still be a relatively new discipline, but deep down, riders feel an irresistible urge to tackle demanding terrain faster and faster. This has been the very essence of mountain biking since its inception. The EX 511 rim is the ideal choice for this quest: a concentration of technology, a multiple EWS winner, in a 30 mm wide profile. Ride harder, ride faster.