Why does it matter?

One of the biggest benefits of carbon wheels is increased aerodynamics. Aerodynamics play a major role in how fast, and how efficiently a cyclist can ride. Think back to when you were on a ride with your buddies, and drafted behind another rider. It's much easier to keep up with them, because of the better aerodynamics when you are drafting.

Aside from your body, your wheels are what create the most aerodynamic drag when you ride. To counteract this effect we increase the 'depth' of the rim. The deeper the rim, the more aerodynamic the wheel will be and the more efficiently and faster you'll be able to cut through the wind. An 88mm deep rim is more aerodynamic than a 38mm rim, and will be faster in situations where aerodynamics are very important, like long fast solo riding and triathlons.

Why would anyone choose 38mm rims, I hear you ask, if 88mm rims are more aerodynamic?

The answer is that by making a wheel more aerodynamic, you also make it more susceptible to crosswinds (winds coming from the side). Let's imagine you’re riding with 88s front and rear. You’ll be able to move quickly because of the aerodynamics of deep wheels, but if a gust of wind comes from the side, it’ll push the whole bike sideways. This isn't such a big deal if you're riding alone, like in a triathlon, but if you are riding in a group of cyclists, this sideways push could cause an impact with other riders. At the very least it will require extra concentration on your part. A wheel with a 'shallower' rim depth, like a 38mm, will be less affected by crosswinds (but will also have less aerodynamic advantage).

Weight is also a major consideration. A 38mm wheel will be lighter than an 88mm wheel - simply because less carbon is used to manufacture the rim. A lighter wheel will accelerate faster and will be much easier to ride up hills. This means that if you’re sprinting and hill climbing a lot, a shallower rim (like a 38) might be best.

Why do I see some riders with different depth wheels front and rear?

As the front wheel can turn for steering, its more susceptible to crosswind interference. The rear wheel is fixed, so if a crosswind hits it, it doesn’t have anywhere near the same impact on handling. This means you can use a deeper rim on your rear wheel.

If you have your own ideas, please contact us(sales1@gofastbicycle.com) to discuss and provide you with customized services.