How Do You Choose The Perfect Rim Depth For You?

Michelle Arthurs-Brennan delves into the science behind selecting the right wheel

- Michelle Arthurs-Brennan Delves

If money were no object, we’d be able to swap wheelsets depending on the terrain, weather conditions and type of riding we intended to do. But most of us cannot afford to buy a lightweight set for mountain rides, deep sections for flat time trials as well as something with an everlasting, perfectly sealed hub for the winter. So, assuming we’re limited to just one wheelset, the question is: how deep should the rim be?

Aero overweight?

The consensus is that gains from aerodynamic efficiency override the benefits of weight saving in all but the most mountainous of scenarios. Dov Tate, founder of British wheel brand Parcours, says: “If you run the numbers, you literally have to climb Alpe d’Huez or equivalent before weight becomes a more important issue.”

The good news is that the capabilities of modern wheels mean that the weight penalty is often minor, anyway.

“These days, wheels are much more flexible in terms of use. The higher-end wheels are getting lighter and lighter, and the aero benefit you get from deeper wheels is almost always going to outweigh any weight penalty,” Tate adds.

Looking within the Parcours range, for example, the 77mm front/86mm rear Chrono set weighs in at 1,625g versus the 40mm Grimpeur at 1,320g — a difference of 305g. For reference, the full 500ml bidon sitting on my desk right now weighs 576g, and I wouldn’t attempt my two-hour lunchtime ride without it.

All of this said, it’s important to know that the biggest jump in performance comes in the move from a box-section rim to a 30mm-40mm wheel with an aero profile; adding more depth is marginal gains territory.