Rolf Prima wheels are engineered to make you faster. The greatest potential for improving cycling speed is through improved aerodynamics.
This chart shows how Rolf Prima wheels can improve your results by just upgrading your wheels.
What does this all mean for you? The less you fight the wind, the more you benefit from your work. This comes into play every time you are digging deep in the aerobars or powering off the front of the pack. You are pushing wind and you want to push the least amount possible. Upgrading to Rolf Prima wheels can make you faster compared to the wheels you’re riding now. This is not just for elite and professional athletes, the aerodynamic benefits of Rolf Prima wheels kick in at lower speeds too – not just the superhuman speeds. See below for more technical details on Rolf Prima’s wind tunnel testing.
Wind Speed: A common concern about wind tunnel testing is the speed at which the wheels are tested. Aerodynamic testing of bicycle wheels is typically performed in a wind tunnel at 30 mph (48 km/h), with the wheel spinning at the same speed. This speed is useful for standardization of the tests and is directly applicable to professional cyclists that often ride at this speed. The data is scalable to slower speeds, but the wind angles don't translate directly. Wheels optimized for 30 mph most often have a specific wind angle at which they excel. This is appropriate for professional cyclists that travel at these speeds but these wheels can actually be slower when ridden at speeds that are typical of different disciplines, or different caliber athletes. Rolf Prima wheels are designed to excel in all wind conditions to give the rider the confidence of knowing they've picked the right wheel set for the day regardless of the wind speed and direction.
Time saved: Time saved changes based on how fast the cyclist is riding because time saved is a percentage of the time a rider is on the course. The slower a cyclist rides, the longer they are on the course so the time savings adds up over a longer duration. The faster a cyclist rides, the less time they on the course so the total time savings is less This is a little complicated but we’ve broken it down in an example below.
To ride a 40km (25mile) time trial at 25mph, you would require a certain power output. This power output depends on numerous physiological, environmental and mechanical factors. For this example, we will assume you ride the 25 mile time trial at 25mph on your current wheels with an average power of 250 watts (250 W) and your time is 1:00:00. Now, if you ride the same course in the same conditions averaging 250 W again but this time you rode Rolf Prima TdF6 SL's you could save 1:17 off your final time, giving you a finishing time of 0:58:43. This means for the same power output you could go faster or for the same time, you could exert less energy. Either way it is a major improvement.
In the same scenario, if you rode the same 40km (25mile) course, but rode at 20mph your final time would be 1:15:00 and you could save 1:35, giving you a finishing time of 1:13:25.
Time saved calculations: The drag figures are normalized for the NACA "standard day" which is 60°F, 29.92"Hg, at sea level. All tests were performed in the wind tunnel at 30mph with the wheel spinning at 30 mph. Aerodynamic drag was measured and converted to time savings over a distance based on a formula developed by Chester Kyle (ref Cycling Science, Spring 1995).
Comparison (Control) wheel: The Mavic Ksyirum SL was chosen as the comparison wheel because it is a common road wheel and it is a wheel people are familiar with and may have ridden. Some companies compare to lower end wheels for wind tunnel tests, but we wanted to compare to a wheel that is higher end and common. It is 18H radially laced front wheel with aluminum bladed spokes.
Wind angle: Many wheels are designed to excel at a specific wind angle which only corresponds to the speeds of professional riders. This means the supposed benefits of the wheel may not be felt if ridden at slower speeds. Our time savings are based on average drag over multiple wind angles showing the time saved for various speeds and wind conditions. Our time savings assumes a loop course in the national average wind speed in the United States which is 9.2 mph.
Tire: Tubular wheels were tested with a 21mm Vittoria Open Corsa CX tire. Clincher wheels were tested with a 20mm Vittoria Open Corsa CX. These tires were selected because they have identical treads and despite the labeled size, their mounted widths are nearly identical. This minimizes the influence of differences between the tires on the test results, ensuring they are comparable.
Wind tunnel: Rolf Prima tested wheels at the A2 Wind Tunnel. The results of this testing show us the reduction in drag compared to a standard wheel, allowing us to calculate the time savings over various distances. The A2 Wind Tunnel is located in Mooresville, North Carolina and is a smaller version of the AeroDYN Wind Tunnel, located next door, which is the leading facility for NASCAR teams to validate racecar designs. With a similar reputation for reliability, the A2 tunnel is the choice for a number of industry-leading manufacturers.