Wider rims can have some impact on aerodynamics, but the relationship is more nuanced and depends on several factors. At Elves Bikes this is a serious discussion for us.
Tire Shape: Wider rims such as our OROME VALAR TH50/TH50D and TH30/TH30D wheelsets can improve aerodynamics when paired with wider tires. Wider tires can create a smoother transition between the tire sidewall and the rim, reducing aerodynamic drag. However, if the tires are too wide for the rims, it can create a less aerodynamic profile.
Crosswind Stability: Wider rims can be less aerodynamically efficient in crosswinds. They create a larger side profile, which may catch more wind and cause instability. In some situations, narrower rims can be more aerodynamically stable. However, our OROME VALAR TH30D wheels, with the lower 30mm profile but with the 29mm rim width, may be the answer
Rim Shape: The aerodynamic performance of a rim is heavily influenced by its shape. Modern aero rims are designed with specific profiles to minimize drag and improve overall performance. Our OROME VALAR TH range uses this formula
Rider Position: The rider's position on the bike can also impact aerodynamics. Wider rims may complement certain riding positions better than others, depending on the rider's torso angle and hand placement.
Rim Depth: Rim depth (the height of the rim) also plays a role in aerodynamics. Deep-section rims can improve aerodynamics at higher speeds, but they may be affected more by crosswinds.
Testing and Wind Tunnel Data: Ultimately, the aerodynamic performance of rims is best evaluated through wind tunnel testing and real-world performance data. Different rim designs perform differently, and manufacturers conduct extensive testing to optimize aerodynamics.
It's important to note that aerodynamics is just one aspect of wheel performance. Wider rims can offer benefits in terms of increased tire stability, better cornering, and improved traction, which can be significant advantages in certain cycling disciplines.
Before choosing wider rims for aerodynamic benefits, it's essential to consider the specific conditions in which you'll be riding, your cycling discipline, and the overall performance characteristics you're seeking. For competitive road cycling, triathlons, or time trials, where aerodynamics are crucial, and a good modern aero rim such as our OROME VALAR TH50 range is a great solution. For other types of cycling or recreational riding, a balance between aerodynamics, comfort, and handling may be more appropriate.