Noken High Volume Air Cap – Compatible with RockShox Zeb Suspension Fork. The MRP Noken is a spring upgrade that increases air-spring volume reducing the compression ratio and creating a more linear spring curve that mimics the plush feel of a coil spring. This simple upgrade addresses a key challenge for many riders with long-travel forks: finding the right balance between a supple initial stroke strong mid-stroke support and fully utilizing all the forks travel. With the Noken you can optimize that perfect trifecta.