As a complete wheelset the 30 course disc brake with its 25mm external and 21mm internal rim widths incorporates design innovations from the 202 firecrest carbon clincher profile for low aerodynamic drag greater stability and predictability in crosswinds that extra wide rim platform allows for increased air volume which spreads the tyre casing that helps increase the contact patch with the ground the result is improved cornering grip and increased comfort on the road mud and everything