ENVE Composites G27 Front Wheel - 650b 12 x 100 Center-Lock BlackENVE Composites G27 Front Wheel 650b 12 x 100 Center Lock Black. The G27 is the ultimate gravel component capable of transforming any drop bar bike into an off road capable rig made for multi day bikepacking routes singletrack adventures and everything in between. Riders on rough and loose terrain who primarily ride dirt often find more confidence and control from a larger volume tire with 650b rim. Those who prioritize traction and stable control