Boundary Hubs are the latest offering from Kris Holm to enable the highest possible strength to weight ratio and pedal performance in a unicycle hub.

The Boundary hub uses the Q-Axle micro spine, which has a larger (24mm) diameter compared to the ISIS-typical 22mm, enabling high strength at 33% lower weight than the KH Spirit hub. Cranks are fixed by tightening two bolts on the crank, which makes them easy to install and remove without wear-and-tear on the splines. The 42 mm bearing and 100-mm bearing-bearing spacing is compatible with all ISIS-ready frames.

Axle: Q-Axle Micro Spline (24mm)
Bearing Spacing: 100mm
36 hole
Weight: 380 g

Our Commitment

Kris Holm Unicycles prides itself on producing equipment that lasts through years of long rides with minimal maintenance or repairs. Should you have any concerns about the quality of your KHU product please refer to our Warranty Policy or contact us.