In April 2017, we dropped news that we were developing a gravel wheel and then silence. While the wheels are not ready for release yet, we want to catch you up to speed on what we’ve been working on and take you on the rest of the ride with us. Today’s post will discuss Part 1 of our FLO Gravel Wheel Design Journey.
Here is a video about this article if you prefer that format.
What Makes A Great Gravel Wheel?
Gravel riding is relatively new, and most gravel wheels to date are modified cross or mountain rims. With the intent to develop a wheel custom tailored to gravel cycling, we wanted to start from scratch. We asked, “What design parameters are important when designing a gravel wheel?” We chose to focus on rolling resistance, aerodynamics, and rim material and construction. Here’s why.
Rolling Resistance aka Crr
Rolling resistance, what is it? The definition taken from Wikipedia is below.
“Rolling resistance, sometimes called rolling friction or rolling drag, is the force resisting the motion when a body rolls on a surface. It is mainly caused by non-elastic effects; that is, not all the energy needed for deformation of the wheel, roadbed, etc. is recovered when the pressure is removed.”
In a cycling wheel, the tire deforms as it contacts the road. This deformation of the tire causes the majority of the rolling resistance. Rolling resistance in tires can account for major losses in performance. For us, getting a solid understanding of rolling resistance and how a wheel can help lower it was critical to the design. A large part of our FLO Gravel Wheel Design Journey relates to the outcomes of what we’ve learned about rolling resistance.
Aerodynamics aka CdA
To learn more about aerodynamics, check out these aero wheel primer articles.
There are two questions - also somewhat of a debate - we considered during this process about gravel and/or mountain bike wheel aerodynamics.
- Do aerodynamics matter for a gravel rider or mountain biker?
- Can you design a wheel to be aerodynamic considering large tires with aggressive tread patterns attached to the rim?
Rim Material & Construction
When comparing gravel riding and road, gravel is much rougher. Wheels take a beating on a gravel bike, so we needed to consider the material and construction best suited for the job while keeping in mind the parameters above.
Our Path Forward
With these three design parameters in mind, we started on a journey to design a gravel wheel unlike anything that exists in today’s market. What we didn’t realize was where it would take us. Tune in next week where we discuss the importance of tire pressure.