Some equipment makes your bike faster. Some makes you faster! PowerTap’s proven, 325-gram PowerTap G3 MTB Rear Disc Hub does both. Make the most of your time on the bike — nail your intervals, stay within your targeted zones for long rides, and track your Training Stress Score (TSS) and Chronic Training Load (CTL) for long-term gains and reaching your goals. The low-profile G3 hub is made of light, durable aluminum with wide flange spacing for a great wheel. The G3 is accurate to within +/-1.5%, and is ANT+ capable for use with your favorite compatible cycling computer (sold separately). Plus, all the electronics are held within a small, easily removed outer cap. Also included is a 6-inch disc rotor for excellent stopping power.