All bicycle tires are tested on a rolling resistance test machine with a 77 cm drum and a 120W electric motor. The drum is covered with diamond plate to simulate an average road surface.
The short video shows the machine spinning up to 200 rpm (29km/h - 18 mph).
Measurements are taken with an Arduino microcontroller and special software. The Arduino calculates the average power required to keep the drum at 200 RPM over a period of 30 seconds. Using a microcontroller to measure input power results in a very accurate measurement.
After a warm-up period of 30 minutes, this test is run three times. I then calculate the average of these three runs. After a correction for the electric motor efficiency and subtraction of the power required to spin the drum and wheel to 200 RPM, the result is the rolling resistance of the tire.
Some facts about the test:
- 77 cm drum diameter.
- Drum speed of 200 RPM which translates to a speed of 18 mph / 29 km/h.
- Diamond plate drum surface.
- 42.5 kg load.
- Butyl tube.
- Computerized measurements.
- Controlled temperature between 21.5-22.5 °C / 70-73 °F.
For a detailed explanation of rolling resistance check Wikipedia.
More Rolling Resistance Tests
- Pendulum Tire Tests by Wim Schermer
Puncture Resistance Test
The puncture resistance test is performed with a 1 mm thick, steel needle to which weight can be added. This needle gets positioned on top of the tire, at the center of the tread. More weight gets added until it punctures the tire. This test is done five times. A score of 10 in the puncture test means it takes twice as much force to puncture when compared to a score of 5.