Parcours have launched a new wheelset with new differential front and rear rim profiles that, they claim, are aerodynamically optimised for 28mm tyres. They've been designed to give a superior rolling resistance, comfort and ride quality without losing speed.
Aerodynamic stability is everything in bike design. If the airflow doesn't stay attached to a wheel, in particular at higher angles of yaw – for example, in crosswinds – it becomes unstable and the turbulence results in increased drag.
So before designs on the new wheels started, Parcours conducted an analysis of real-world wind conditions and the impact of yaw angle on wheel design. Collecting wind angle data from sensors located at both front and rear wheels, Parcours found that the average yaw angle at the front wheel was consistently higher than at the rear. This was due to airflow at the rear wheel being affected by the front of the bike and rider interaction (predominantly legs, feet and pedals). Additionally, crosswind-handling performance at the rear wheel is significantly less important since the wheel is not free to move on its axis for steering.
Strade is the result, a wheelset designed around a 28mm tubeless tyre, which has not only front and rear-specific rim depths but also different rim widths.
For the Strade front, Parcours developed a wide, U-shaped rim designed for higher yaw with a depth of 49mm and an external width of 32.0mm, while the rear has a narrower, sharper, V-shaped rim with a depth of 54mm and a width of 30.5mm, which is better suited to lower yaw angles.
Parcours ran an iterative CFD design process and then validated the prototypes at the A2 Wind Tunnel in North Carolina. They say the wheels outperformed the brand’s existing Passista Disc by a wide margin in aerodynamic performance and crosswind side force.
The Strade wheelset runs on Parcours’ precision-machined alloy hubs, which are fitted with high-grade EZO cartridge bearings and use a Centerlock disc fitment. The hubs are fitted for 12mm thru-axles front and rear (adapter kits are available for other axle standards).
Parcours uses Sapim CX-Ray aero spokes, 24 front and rear in a 2-cross pattern, which they claim make the Strade robust enough for whatever you throw at it.
Dov Tate, founder of Parcours, says: “With the shift in tyre and braking technologies, we set out to create a new-generation wheel that maximised the aerodynamic and handling improvements of a wider rim and tyre. The result was the super fast, super stable Strade, which exceeded our project goals and sets a new benchmark in the mid-depth disc wheel category.”
Parcours Strade wheelset specification
Weight: 1,520g (front 690g, rear 830g)
Rim depth front: 49mm
Rim depth rear: 54mm
Max external rim width front: 32.0mm
Max external rim width rear: 30.5mm
Internal rim width (front and rear): 22.5mm
Spokes: Sapim CX-Ray 24 front, 24 rear
Hubs: Parcours Disc
The new disc-specific, tubeless-ready Strade wheelset has been developed in partnership with the sports engineering department at Nottingham Trent University.