Rotor Direct Mount Q-Ring Rex Rotor meets the demands for smaller, lighter chain rings with the Rotor Direct Mount Q-Ring. It is a simplified one-piece design that saves about 40 grams compared to other standard set ups. The direct mount chain-rings are machined from a single piece of aluminum, making them lighter and more rigid and durable. Rotor Q-Rings vary drivetrain resistance during a pedal rotation to align with your leg's natural strength spots and weak spots to boost your overall efficiency. In doing so, Q rings wisely utilize the strongest muscle groups to increase positive work, while picking up the slack in the weaker zones to reduce the negative work, potentially increasing a competitive cyclist's performance by as much as 4 seconds per km in an all-out sprint. That may sound miniscule, however it's twice the benefit of an aero wheelset, and in a sport where a second can be the difference between the top step of the podium and no podium at all; these proportions are substantial. Features OCP3Chainline: standard Direct mount compatability: Rotor | Rotor | Direct Mount Q-Ring Rex | Black | 30T | Aluminum