Interbike tech: Kappius hubs eliminate 'black hole'

240 points of engagement: the Kappius freehub has four pairs of pawls, each slightly offset from the angles relative to each other that would have them engage all of the same time; only one pair engages at each position of the toothed ring surrounding them. Photo: Lennard Zinn | Singletrack.com

How do you get to 240 points of engagement? The four pairs of pawls inside the Kappius freehub multiplied by 60 engagement teeth equals 240 different positions the freehub locks up in, or 1.5 degrees between clicks. And those pawls flip out by magnets repulsing each other behind them, not by springs pushing them out from behind! Photo: Lennard Zinn | Singletrack.com

The rotor-mounting platform is totally hollow yet super stiff on Kappius mountain bike hubs. Photo: Lennard Zinn | Singletrack.com

Cutouts and a huge shell diameter not only make Kappius hubs superlight and stiff, but blast this hollow hub with cold water and it won't suck the water into the bearings like closed hubs will, as closed hubs suddenly create a vacuum inside when the hot hub is hit by cold water. Photo: Lennard Zinn | Singletrack.com

Yes, also singlespeed riders can get 240 points of engagement and almost immediate lock-up and forward propulsion after coasting. Photo: Lennard Zinn | Singletrack.com

Another view of the singlespeed Kappius Unibody cog design; it slip-fits over the freehub body. Photo: Lennard Zinn | Singletrack.com

Kappius makes superlight and stiff Lefty hubs too. All new Kappius hubs have angular-contact bearings in them. Any configuration of Kappius front hub costs $300; rears are $700. Photo: Lennard Zinn | Singletrack.com

Kappius hub user and devotee Christoph Sauser says the Kappius freehub sounds like a "swarm of bees!" He calls the dead space before the hub locks up "the black hole" and says he won't race on any other hub now that he's found one that gives him "no more black hole." Photo: Lennard Zinn | Singletrack.com

Russ Kappius calls his cogset design "unibody." He machines out the center of the largest SRAM XX cogset in order to attach it to his unibody dish that slips onto the cup containing the 60 engagement teeth surrounding the pawls (the rest of the hollow SRAM XX cogset is "already there," to make his proprietary cogset, he says). Photo: Lennard Zinn | Singletrack.com

The completed cogset has a lockring on it that can be unscrewed to remove the last cog, but there is no need to. It slides onto the freehub body and is secured by a threaded end cap on the axle. Cogset cost: $400. Photo: Lennard Zinn | Singletrack.com

Russ Kappius with his cogset. It won't fit on any other freehub body other than his, but his system is more efficient. The bike industry has adapted to losing interchangeability of bottom brackets and headsets and hub axles; it remains to be seen whether a lighter, stiffer, faster-engaging freehub that only accepts a Kappius cogset will gain wide traction among riders. Photo: Lennard Zinn | Singletrack.com