Zipp's ZR1 SL is a race-ready, lightweight hub set designed for high performance and durability. The SL version is modeled after its predecessor, the ZR1 hub, and features a lighter hub shell and bearing system. This hub set has been specifically developed for our top-tier NSW wheels and is now available separately. The ZR1 SL comes with carbon steel bearings, with an upgrade option for ceramic bearings to reduce weight. The hub design provides a quick engagement feel with 66 engagement points. The six pawls are staggered to operate in two groups of three pawls, ensuring that three pawls engage at all times. This means that the power from your legs is quickly transferred to your wheels. The freehub design ensures that the pawls stay in place during disassembly, making maintenance easier. Zipp hubs use J-Bend spokes, which are the most common type of spokes today. J-Bend spokes are widely available and easier to replace. ZR1 hubs are approved for use with road or gravel e-bikes with light assistance, as long as the motor torque does not exceed 60 Nm.