Hollow:~ Hollow Hubs feature cold forged and CNC-machined 6061-T6 aluminum shells fitted with precision sealed bearings and 20-millimeter 7075-aluminum axles and axle nuts. Besides 100- front and 110-millimeter rear spacing they also feature oversize 32-millimeter dropout interface washers which further increase the stiffness of the wheels.
• Race-proven 20-mil axles help transmit more power from the pedals to the wheels
• More reliable and weigh less than many cassette hubs and most important, have 20-millimeter axles
• Meets or exceeds ENBMX standards