The hub is centered on Zipp's Axial Clutch mechanism, which features two Metal Injection Molding (MIM) ratcheting rings — one mated to the freehub body and one mated to the hub body. The two rings are machined like a ratchet, so they ramp off of each other while freewheeling but engage each other during pedal input.
Compared to a standard pawl design, which actually resembles a drum brake, the Axial Clutch's MIM rings engage laterally to reduce friction while freewheeling, so coasting doesn't negate watts already spent. We're familiar with this model, as we've seen similar mechanisms on the designer hubs featured in top-end custom builds for years now, but Zipp is the first to replace the usual tensioning agent, steel springs, with magnets. This substitution further reduces friction between the ratcheting rings, making for what may be the smoothest freewheel on any mass-produced hub set. It's a design that we suspect will eventually be the norm, but — once again — Zipp is leading the charge.
- Upgrade your wheels with a stiffer, faster hub
- Axial Clutch with MTM ratcheting rings ramp you forward
- Magnetic tension reduces friction while freewheeling
- Ratcheting freehub resembles boutique model on custom wheels
- 10-degrees of engagement for near instant propulsion
- Low-drag coasting for boost in speed down windy canyons