Chris King

Boost 6-Bolt Hub

What Our Gearhead® Experts Are Saying:

"I spec the Chris King Boost 6-Bolt Rear Hub on builds for riders who want something they will never have to think about replacing. The RingDrive engagement is the fastest I have felt on any MTB hub at any price, the bearing quality is genuinely unmatched at this level, and the fact that the whole thing is fully rebuildable in the field means there is no reason this hub ever leaves a rider's stable."

Mountain bike hubs exist on a spectrum from adequate to exceptional, and the Chris King Boost 6-Bolt Rear Hub occupies a category of its own at the far end of that range. Designed specifically for the 148mm x 12mm Boost axle standard that defines modern trail and enduro geometry, this hub is a precision instrument built to extract maximum performance from every component it connects. The one-piece solid axle eliminates flex between the dropout interfaces, which translates directly into more accurate suspension tracking and a cleaner transfer of pedaling input to the rear wheel under load.

The engineering centerpiece is the patented RingDrive system, which delivers 72 simultaneously interfaced points of contact between the drive ring and the hub shell. Compared to conventional pawl-and-ratchet systems, this architecture eliminates the lag between unweighting and re-engagement, meaning power transfer is effectively instantaneous the moment you load the pedals. The flanges are canted outward to increase the bracing angle of the spokes on both the drive and non-drive sides, producing a laterally stiffer wheel with more even tension across the lacing pattern. Bearing quality is where Chris King has built its reputation across five decades, and the Boost 6-Bolt Rear Hub carries that forward with heat-treated, surgical grade steel races machined simultaneously using tools of equal wear to produce matched tolerances that tighten and improve as the bearing tracks burnish with mileage. Ceramic bearing upgrades are available for riders who want to push rolling efficiency further. Heavy-duty bearing seals and a threaded driveshell seal ring protect the internals from the mud and water exposure that inevitably comes with serious trail use.

Compatibility spans Shimano HG, Micro Spline, and SRAM XD driveshells, and the hub is available in 28h and 32h drilling to suit a range of build requirements and intended use cases. Full serviceability is a core design principle rather than an afterthought: the entire hub can be rebuilt in the field with a T10 and a pick, and the Universal Hub Service Tool handles more involved overhauls. Every unit is engineered, manufactured, and assembled under one roof in Portland, Oregon, backed by the Chris King lifetime warranty and a company philosophy that treats durability as a baseline rather than a selling point.