World's first wind tunnel for bikes is empowered by National Instruments



Bicycle wind tunnel

Anyone who thinks cycling is a simple matter of pedal power has overlooked the growing role of scientific research in helping both amateurs and professionals travel faster on two wheels. In pursuit of maximum speed and efficiency, bike and equipment manufacturer Specialized has created the world’s first wind tunnel dedicated to cycling, using test and measurement technology from National Instruments to give engineers an unprecedented insight into performance levels.

The breakthrough facility, built at the California headquarters of Specialized, has been specially designed for engineers to assess new ways of overcoming one of the biggest challenges that cyclists face: the inhibiting effect of drag caused by wind.
The company will investigate ways to enhance equipment, bikes and riding positions that could help professional athletes secure the split-second advantages that separate winners from losers, as well as helping everyday commuters cycle to work without working too hard.

Specialized is the first bike manufacturer to build a sport-specific wind tunnel as opposed to relying on third-party facilities more commonly used for automotive and aerospace testing.

The unique project required the team to develop an entirely new measurement and control system and it was here that NI became a pivotal partner, configuring a bespoke arrangement of hardware and software to put sophisticated testing capabilities at the fingertips of the engineers. The system gives them the ability to collate data on crucial parameters such as airflow and incorporate visual feedback from cameras, as well as adjust the test conditions.

The resulting facility will enable innovations for the cycling industry that would not have been possible previously, according to Chris Yu of Specialized Bicycle Components.
Drag is one of the biggest challenges for cyclists to overcome. As they pick up speed, their bodies, bikes and equipment cause a separation of air, resulting in resistance. Because drag increases with speed, riders feel more resistance at higher speeds and require more power to overcome the forces working against them. According to research, between 70 percent and 90 percent of the power a cyclist generates is solely used to overcome aerodynamic drag.

By finding ways to minimise drag – through effective body positioning and aerodynamically refined equipment – Specialized aims to help cyclists achieve maximum power and efficiency.

Sportsman Chris Alexander, three-time Ironman World Champion, said, “In the past, I think there was a mentality that the rider’s fitness would supersede everything. But what we’ve found, with the evolution of equipment, is that minimising drag and aerodynamics plays a huge role because you want to be able to expend your energy in a way that gives you a massive return on investment.”

Traditional wind tunnel testing can be time-consuming and inconvenient for bike manufacturers to use and with the bike rigidly bolted to the tunnel it was difficult to recreate the real-world movement that a bike and rider would experience.

The new facility delivers all aspects of aerodynamic testing to the headquarters of Specialized in Morgan Hill, California, and because it allows for continuous movement, it more accurately recreates the dynamic conditions of the real world. This gives the company the ability to conduct a continuous loop of development and testing for all its bikes and equipment, supporting its team of professional cyclists by evaluating and optimising their riding positions.

Specialized Aerodynamics Engineer Mark Cote said, “We’ve already put 10 of our professional athletes through and it’s a complete game changer. The design is specific for our needs and we can measure very precisely. The test section is big enough for multiple bikes and riders. One of the biggest things we’ll be able to do with this wind tunnel is make life better for the average commuter. If you’re riding to work every day, you want to be less sweaty and you want to get there faster to make your meeting.”
Crucial to the groundbreaking success of the wind tunnel is a uniquely configured test and measurement system from National Instruments, comprising both software and hardware to provide engineers and sports scientists with maximum flexibility and control, consolidated in a single system.

Specialized used NI LabVIEW system design software, NI PXI hardware and the NI Vision Development Module integrated with commercial off-the-shelf components such as cameras. This was assembled and seamlessly integrated in just a few months.
With LabVIEW, Specialized can interface with sensors positioned on both the bike and the cyclist in the wind tunnel while engineers monitor the resulting data on an iPad using the NI Data Dashboard for LabVIEW mobile app. Real-time visual data captured by cameras is integrated into the system by the Vision Development Module.

The flexibility of the NI PXI chassis, which gives users the ability to rapidly swap hardware, helps Specialized quickly create additional tests using new sensors and controllers. This significantly reduces turnaround times, for example, when switching between R&D testing on equipment and performance testing on professional athletes.
LabVIEW provides a single software framework to meet the unique requirements of performing control, measurement and vision acquisition. The consolidation to a single software solution, tightly integrated with reconfigurable hardware, also simplifies maintenance and support for the system.

Chris Yu of Specialized Bicycle Components said, “Everything about this tunnel, from the data acquisition to the control of our bike fixtures, is all run off National Instruments hardware and software. We chose to work with NI in building this sport-specific wind tunnel because of the ability to integrate a variety of I/O and modern instrumentation, the flexibility to adjust small variables and easily change the tests, and the speed at which this unique system could be developed to address our specific measurement needs. Being able to access custom testing 24/7 will lead to innovations for the cycling industry that may not have surfaced otherwise.”

National Instruments