Reducing the drag of the wheelset – and the complete system of the rider and his bike – is one of the three key points of the AERO+ technology. CFD (computational uid dynamics) simulation and a special black box process set the base for the development of wheel prototypes, which are then tested in the wind tunnel. Hereby we can verify that the wheel has low drag numbers at all yaw angles and a smooth stall behavior.
The Aero+ technology has been developed in cooperation with our aerodynamic partner Swiss Side to optimize our new Endurance wheelsets, the ERC 1100 DICUT® foremost. It describes our approach to optimize a wheelset via numerous engineering techniques all through its development process. Aero+ is based on three pillars: DRAG, HANDLING & EFFICIENCY.
The complete bike only makes up for 25% of the overall drag, the wheels even less at 8%, while the rider causes 75% of it. So why is the wheel still important in this calculation? In order to stay aero in the first place, you have to stay comfy no matter the riding situation, because only then will you be able to keep an aero position, which affects those big 75%. The wheelsets have a huge influence on handling characteristics and this is why wheels are key when it comes to optimization of the handling.
The steering moment describes the force the rider needs to apply to the handlebars to keep the front wheel straight. Over the relevant yaw angles the change in steering moment should be as even as possible and show as little spikes as possible. If these demands are met, the wheel has good handling characteristics and allows you, the rider, to stay aero.
Comfort, grip and rolling resistance define efficiency. Wheels have a direct and important effect on how the tires perform regarding comfort, grip and rolling resistance. These factors play an integral role in the Aero+ concept, because you can only stay aero, when you stay in control. Wider rims – like we use them in our Endurance category – support wider tires better.
Influence of rim width
|Rim width||Rolling resistance|
|15 mm||37.6 Watt|
|18 mm||37.4 Watt|
|19 mm||36.9 Watt|
Those tires have a wider contact area and can be run at lower pressures resulting in more grip and more comfort. The better support of the tire allows for more aggressive cornering before the tire starts to fold or to run lower pressures respectively. Furthermore wider tires and wider rims have a positive influence on rolling resistance as we could verify during our comprehensive tests.
Influence of tire pressure
|Tire pressure||6 bar||7 bar||8 bar|
|Continental GP4000S 25 mm||39.8 Watt||39.0 Watt||37.6 Watt|
|Continental GP4000S 28 mm||37.5 Watt||37.4 Watt||37.2 Watt|