FLO Gravel Wheel Design Journey Part 5 – Roller Testing – Measuring Rolling Resistance

The key to our Gravel Wheel Design Journey and determining how a rim could improve rolling resistance was accurately measuring the rolling resistance of different tire and rim combinations.

Rolling resistance testing

First, we measured rolling resistance on rollers.  Tom Anhalt is the king of rolling resistance testing on rollers.  So naturally, we reached out to Tom and had him walk us through the tools needed and the best protocol to follow.

Eventually, we would have to hit the road for true rolling resistance measurements, so we didn’t plan for an in-depth view of all the tires. Additionally, there are a number of recent studies that show how rolling resistance is affected by the surface of the road and something called impedance.  Tom Anhalt and Josh Poertner, over at Silca, have pioneered this area of work.  We will be adding to this research later in this series.

Can We Measure Rolling Resistance

On-road rolling resistance is a difficult thing to master.  Before measuring on the road, we wanted to ensure we could get predictable results on rollers.  If we could solve for known values, then we could comfortably move to the road for testing and determine a protocol that would work.


After a large number of tests, we successfully measured rolling resistance on rollers, repeatably. Rolling resistance numbers for tires on rollers are available online, so we will not post them here. However, we will share the numbers from on-road testing.  But that will be for another post.
The next phase of our Gravel Wheel Design Journey takes us to on-road testing.  Developing a protocol took a lot of time, and we hit a ton of roadblocks. We will start from the beginning in Part 6 next week.