Colorado’s Kappius Components made a compelling case for its new KR-29-XCW wide MTB rim at the Sea Otter Classic. In a side-by-side comparison, the new Kappius rim netted nearly a third of an inch greater tire width than an ENVE XC rim when both were mounted up with 2.35 Maxxis Ikons.
The benefit of wide MTB rims is also pretty compelling: improved cornering and braking traction, reduced risk of tubeless burping, and the ability to run lower pressure. That final point is critical. Wider rims help separate tire pressure from sidewall support, so you can run lower pressure and not risk an unnerving wallowing ride feel.
As the photos below illustrate, the Kappius rim pushed the tire to nearly 2.45 inches, while the ENVE maxed out at 2.18. Both tires were pumped to 15psi. And Kappius co-founder Rus Kappius claimed he’d raced the KR-29-XCW earlier that day at 12psi.
“Traction was amazing,” he said.
Indeed, following the likes of Ibis, Kappius has pushed into the wide rim arena with a new hoop that measures a claimed 46mm outer width and 41mm internal. For compassion sake, the pictured ENVE is 24mm/19mm. This added width nets increased tire air volume, which means greater bite and stability, especially when cornering. At 15psi you could easily fold the bead of the Maxxis tire mounted on the ENVE just with your hands, while the Kappius held firm under the same duress.
The new rims have a claimed weight of 450g and retail for $699 apiece. A fully built wheelset using Kappius KH-1.5 hubs sells for $2200 with a claimed weight of 1550g. The wheels are tubeless ready and have an offset spoke bed that’s designed to increase strength. Here’s a full rundown of spec and highlights of the new Kappius KR-29-XCW rim.
- 46mm external width
- 40mm internal width at bead
- Recessed bead channel to prevent burping
- Shallow, wide center channel for ease of tubeless inflation
- 5mm offset spoke bed for added wheel strength
- 450g per rim (28- and 32-hole)
- $699 per rim
For more information visit www.kappiuscomponents.com.
This article is part of Mtbr’s coverage of the 2015 Sea Otter Classic in Monterey, California. For more from Sea Otter CLICK HERE.