Quicker than a pack of speeding bees and stronger than the rock looking to blow it apart, the Industry Nine Hydra Classic Rear Superboost Centerlock Mountain Hub brings best-in-class response to all sorts of mountain biking. Hydra uses mind-blowing . 52-degree engagement to allow for a near-instantaneous pedaling response. Made with 32-hole rims in mind, these hubs are purpose-built for downhill and enduro shredding.