In early 2020, we released the world’s first deep profile gravel wheels– which means, gravel wheels that are aero. You may be thinking that a deep gravel wheel doesn’t make sense since there is no way a gravel wheel could be aerodynamic with such aggressive tire treads.
But, with lots of research, testing and design, we made it happen! The FLO gravel wheel is about 11 watts faster than a standard gravel wheel. The watt savings isn’t the only benefit to this wheel design; other benefits may, in our opinion, even outweigh the aero benefits in certain situations. Here are three reasons why you need deep section gravel wheels:
Reason 1: Rider Comfort
Gravel cycling is fairly new and is gaining popularity. If you’re like me and have made the transition from road to gravel, you probably understand the difference in how much vibration you feel while riding a gravel bike. The variations in terrain has your front wheel bouncing left to right and you finish the ride feeling like you just rode a paint shaker. Gravel bikes do not have shocks, so we are left to manage vibration in other ways.
A deep section rim acts like a leaf spring, if designed properly. The side walls of the carbon rim flex and absorb the vibration produced by riding over bumpy terrain. If vibration isn’t dampened, it makes its way into the body – hence the paint shaker feeling. But, the carbon rim helps to reduce that vibration making for a much more comfortable ride. Riding the G700 and G650 drastically reduces the vibration you feel in your body and makes riding gravel more enjoyable.
Reason 2: Better Grip
Grip is essential to cycling in that it allows you to corner confidently and faster, and it transfers your power to the terrain more efficiently. Losing grip happens because of a couple different scenarios: one, if your tire comes off the ground, your wheel has nothing to grip and you lose contact with the surface; two, the friction of the surface changes. For example, if you’ve walked on ice, you know you have less grip than walking on pavement.
How does a deep section gravel wheel help you grip? That’s a good question. As we learned in reason one above, a deep section rim absorbs vibration when it acts like a leaf spring. This not only helps by reducing vibration above the leaf spring, but it also helps the wheel keep contact with the road surface since the bumps in the terrain are absorbed into the leaf spring. Keeping contact with the surface obviously helps with grip.
A good way to visualize this is to think about riding a mountain bike. First, think about riding a bike without shocks, you can probably feel how bumpy the ride is and may have even gotten some air on a couple bumps. Now, think about riding the same line with a bike that has shocks, the ride is much smoother and your wheels keep contact with the ground. So, you can think of deep section gravel wheels like shocks, allowing you to stay in contact with the surface and have better grip to maneuver the trail.
Reason 3: Aerodynamics
Yes, a deep section gravel wheel has huge aerodynamic benefits over a traditional box rim even with an aggressive tire tread. During the design of the G700 and G650 FLO Gravel Wheels, we proved that a deep section gravel wheel provides the same aero benefits that you would see by selecting an aero road wheel over a box section road rim. That savings is 11 watts. That’s right, going from a box section gravel wheel to a deep section gravel wheel give you the same 11 watt savings you see on road wheels.
You may however be wondering why aerodynamics matter for a gravel cyclist. There are a few reasons. First, if you race then you want all the free speed you can get. Saving 11 watts will drastically lower your time on the course. 11 watts can easily make the difference between 1st and 10th place. Even if you are not racing, saving watts allows you to go further for the same amount of energy. Why not see more on your ride?
Another benefit to an aerodynamic design is wheel stability. This is good for racers and enjoyment riders. When developing rim shapes, we use a weighted algorithm that looks at drag and the amount of yaw torque a rim shape experiences. Yaw torque is how the wheel responds to cross winds and how stable it is in that wind. Then, the algorithm optimizes both so we arrive at an optimal rim shape.
Gravel requires larger tires, which can be difficult to handle in the wind but with the method mentioned above, we design our rims with large tires to optimize and help balance the front wheel in cross winds. So, while the main benefits of aerodynamics is drag reduction (so you go faster), there is also an improved stability for the rider. I’ll take all the stability I can get on a bike!
Gravel cycling is in its infancy, and brands like FLO are making huge efforts to design products that work really well for gravel-specific riding. Don’t be sold on a road rim that is converted to a gravel wheel. You simply will not experience the benefits of a wheel design specifically for gravel. Pick up a set of FLO Gravel Wheels for your next ride and feel more comfortable, corner like never before, all while being faster.
Co-founder at FLO Cycling. Jon manages the day to day operations and acts as the lead engineer for all FLO products.