Key to their aero performance is the 32mm outer width that helps
to maintain flow attachment from wider tyres, creating a narrower
wake and reducing drag.
In its own testing against key rivals, Cannondale claims the
wheels produced less drag at 0-degree yaw angles compared to the
Roval CLX 64, Mavic Comete and Enve 4.5 wheels. Only the Roval tops
the new wheels at a wider range of yaw angles.
Is it fast?
In its testing, Cannondale claims the new SystemSix produces
lower drag at all wind angles than the Scott Foil, Pinarello Dogma,
Canyon Aeroad, Giant Propel, Specialized Venge ViAS Cervelo S5,
Felt AR and Trek Madone.
Cannondale says that the aero advantage of the new SystemSix
ensures it is faster than the SuperSix Evo, or any lightweight
climbing bike, up to a 6% gradient or more.
So if you're racing and riding largely on flat roads with no
mountain ascents, the SystemSix is the bike to choose over the
venerable SuperSix Evo (still one of my all-time favourite road
It's true that wind resistance is the biggest obstacle you face
when cycling at speeds in excess of 20mph on flat roads. As much as
90% of your energy is consumed by pushing through this invisible
force. That's why aerodynamics has become such a big influence in
the design of road bikes in the past two decades.
On a flat road, Cannondale claims the new SystemSix can save as
much as 25-30 watts at speeds of above 35kph. At a cruising speed
of 30 kph on a flat road, the SystemSix will save you 10% power
compared to a traditional road bike.
But when the gradient tips above 6%, the impact of wind
resistance on your speed reduces as that other invisible force,
gravity, starts to work against you. On such gradients weight
becomes a growing concern to your speedy progress.