Our aim at Evolve Aero is to continually improve the performance benefits of our products with a rolling programme of aerodynamic research and development.  Aerodynamic drag accounts for between 70-90% of the resistance encountered by a cyclist riding on the flat at typical race speeds (35-50kph), the higher the speed the higher the drag created. The potential gains to be made here far outweigh other measurable factors such as weight and rolling resistance, which is why we focus our efforts on aerodynamics in particular.  We gather our data using various methods – Wind Tunnel testing, indoor Track testing and outdoor field testing using the latest live aero data analysis,  all of which offer a reliable controlled testing environment but have their own strengths in the data they gather.  Combining that data helps us to develop wheels and components that perform to the highest level.

Aerodynamic rider positioning and drag reducing equipment in a quest to reduce CdA (Coefficient of drag) has become an arms race and an area where it’s all too easy to fall behind and is often the difference between winning and losing.

Wind tunnel testing

We use three reliable facilities, the R J Mitchell located at the University of Southampton, the Boardman Performance Centre and the latest Silverstone facility.  These are cycling specific and testing is carried out at the relevant wind speeds and angles or ‘yaw’ typically encountered by a racing cyclist.  Typically the subject rider is pedalling, wheels are in motion so we can gather data as close to real world conditions as possible.  CdA (Coefficient of drag) is measured and averaged from hundreds of readings within each test condition undertaken. These readings can then be converted into time savings or losses for each test variable.  What we must remember here is that as previously mentioned these test conditions are controlled for accurate comparisons but the predicted time savings achieved in the tunnel aren’t always fully realised on the open road in race conditions. Variables such as gusting or swirling winds, traffic pushing and pulling forces and the inability to maintain that perfect position while negotiating technical areas or through fatigue all have an immeasurable impact.

Track Testing

This is carried out on an Indoor Velodrome using computer software that measures the correlation between power and speed to calculate CdA.   This type of ‘real time’ testing involves our subject rider lapping the track making equipment or positional changes for comparison.  A mounted computer takes live readings from the power rig which is then downloaded track-side for immediate analysis after each test condition.  Using an initially established baseline the software calculates the CdA of the rider which determines the performance of that particular wheel or component being tested providing us with an accurate fastest to slowest running order.  One variable that this testing takes into account that the Wind Tunnel doesn’t is rolling resistance (Crr), which means that all wheels must be fitted with the same tyres and inflated to the same pressure to ensure accurate comparisons.  However some subject wheels may work better aerodynamically with narrower tyres or be restricted in format to ‘Tubular’ tyres and perform well in the Wind Tunnel but then test slower as an overall package in Track Test conditions.

The limiting factor of this testing is that the angle of Yaw is ‘0’ degrees on the track straights while debate continues as to whether there is any measurable Yaw generated while riding around the banking.  Once again this leads to a degree of ambiguity in relating the data to real world out door race conditions where higher Yaw is generally experienced.  For testing Track racing specific equipment it’s 100% accurate.

Outdoor Field Testing

This follows a similar protocol to Track testing and uses the same aero software to gather data.  The benefit here is that real world conditions are experienced.  Repeat runs are carried out over the same streatch of road on the same day in an attempt to acheive consistent test conditions.  This way of testing typically takes longer to gather data but is free and can be carried out as and when required.  An essential tool when it comes to prototyping wheels and components pre production.

Data Results