Mavic Cosmic Carbone CXR 60 T wheelsetJeff Jones/Future Publishing
When you ride at an angle to the wind direction, you experience drag force (FD) and lateral force (FL), among other forces. These are what Mavic measure in the tunnelMavic
How the sail effect works. There is a small amount of positive drag force when certain wind conditions are met. This definitely doesn’t mean you don’t have to pedal – think of it as a small boost in certain situationsMavic
Mavic came up with this weighting law to average out the time typically spent at various yaw angles. They work out time savings for wheels using this averageMavic
Mavic’s on-the-bike anemometer, to measure all the different wind angles that the rider encountersJeff Jones/Future Publishing
This chart compares a Ksyrium (grey), Cosmic Carbone Ultimate (red dot), CC 80 (black crosses) and CC CXR 80Jeff Jones/Future Publishing
Front wheel drag tests vs complete bike tests. The trends and gaps are the sameMavic
A pair of CXR 80s vs a CXR 80 plus a Comete disc. The disc is better at higher yaw due to the sail effectJeff Jones/Future Publishing
Wheels only count for 7 percent of the rider’s drag, Mavic say, but any saving is worth havingMavic
The rim strip is easy to clip on and offJeff Jones/Future Publishing
Mating the tyre to the rim and smoothing via a removable plastic strip means Mavic can optimse the shape of the whole wheelJeff Jones/Future Publishing
The spoke bed is snub-nosed but not quite as thick as a 404Jeff Jones/Future Publishing
The CXR 60 Cs have a rim strip and an Exalith braking surface. The tubulars don’t possess this and won’t give as good a braking performanceJeff Jones/Future Publishing
The Mavic Cosmic Carbone CXR 60 C wheelset (the clincher version)Jeff Jones/Future Publishing
The two tyre and rim profiles for the CXR 60 C and T models. There are subtle differences in shapeJeff Jones/Future Publishing
The CXR 60 C outperform the tubulars slightly at lower yaw angles, until they stall at 15 degreesJeff Jones/Future Publishing
Comparison between CXR 60s (L) and Zipp 404 FC (R). Under Mavic’s code, ‘2’ = 5 degrees of yaw; the numbers in the column next to that are drag. In this run the Zipp is slightly better at 5 degrees than the CXR 60 but that soon changes when you hit 4 (10 degrees), the stall angle for the ZippJeff Jones/Future Publishing
The Geneva wind tunnel is situated below this bridge. It’s not easy to find space to build wind tunnels, and this was a cheap and good option, due to the climate stability insideJeff Jones/Future Publishing
The back end of the wind tunnel in Geneva, which Mavic use extensively for product developmentJeff Jones/Future Publishing
The Cervelo P5 test bike on the rig in the tunnelJeff Jones/Future Publishing
Jean-Pierre Mercat, head of Mavic advanced research, gets ready to rumbleJeff Jones/Future Publishing
Getting the wheels rolling via the mechanism built into Mavic’s balanceJeff Jones/Future Publishing
Zipp 404 Firecrest and Bontrager Aeolus wheels ready to be tested in the tunnelJeff Jones/Future Publishing
The graph of lateral force vs stability seemingly shows the Mavics behaving fairly predictably as wind angle increases, whereas other wheels don’t. But they didn’t measure steering torque only lateral force on the wheels. We would be very wary of saying these results applied in the real worldMavic
Mavic say their Cosmic Carbone CXR 80s save 6.4W (15 seconds in 40km at 50km/h) on average over Zipp 808 and Hed Stinger 9Mavic
Mavic’s wheels tested against others on neutral ground at the San Diego wind tunnel. The Bontrager Aeolus 7 pips them at -15 degrees but the Mavics win everywhere else (CC 80 is their Cosmic Carbone 80 model, which doesn’t have the CXR profile so isn’t as good aerodynamically)Mavic
Mavic say their Cosmic Carbone CXR 60 Ts save 6.3W (19 seconds in 40km at 50km/h) on average over Zipp 404, HED Stinger 6, and Enve 6.7 wheelsMavic
Mavic simulated how much pro triathlete Frederik Van Lierde would save in the Kona bike leg on CXR 80 wheels over a set of Zipp 404s, given average wind conditions based on 20 years of climate dataJeff Jones/Future Publishing