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How Much Faster Are Carbon Wheels?

Carbon vs. Alloy Wheels

People frequently ask about the difference between alloy wheels and carbon wheels. But what exactly is the difference?

The majority of bikes come standard with alloy wheels, and only the priciest road bikes would typically include carbon wheels. Despite this, they’re a pretty common upgrade part for the majority of people’s bikes. A set of carbon wheels costs about £500, €600, or $700 if you live in the US. In contrast to alloy wheels, however, they also cost between 1,000 and 2,000 euros, pounds, or dollars due to the expensive production process.

In comparison, a good quality pair of alloy wheels will typically cost between £100-£700 or dollars. So purchasing a set of carbon wheels should be done with caution.

In this article, I will explain the differences between the two so that you can make the best decision possible.

Visuals

The first difference is obvious and that is visuals. You may not be the fastest rider, but you certainly look fast, and that is all that matters. Alloy rims have traditionally had an unpainted brake track because braking on that surface caused the paint to chip off. As a result, manufacturers simply kept it there. This is, however, changing.

Disk brakes are becoming more popular on road bikes, as well as more affordable. And if you have an aluminum disk brake wheel, you can paint it any color you want because the braking is done at the disk, so the paint on the rim will not wear off. As a result, you can have a relatively low-cost wheel like the Vision, TRIMAX 30. Yet it can be all black, almost carbon in appearance, which is very classy.

Other than the looks, carbon rims can also be made lighter than the equivalent alloy rims. They can also be more aerodynamic because the rim depth can be increased significantly. A super deep alloy rim would be extremely heavy and probably quite uncomfortable to ride.

Weight

The next significant difference is weight. Without tires, an entry-level aluminum wheelset typically weighs around 2 kilograms. Now consider a carbon clincher with a deep section rim, such as the Vision Metron 55. Well, this weighs around 1.5 kilograms for a pair without tires. That’s a savings of about half a kilogram. However, carbon wheels can be even lighter. If you got some top-of-the-range, lightweight carbon wheels, they can weigh as little as just a kilogram per pair.

That may not seem like much, but it is very noticeable when riding, especially when accelerating or attacking up a climb. The area of the wheel where weight is most important is the rim.

The reason for this is that the mass has a greater moment on the wheel’s center axis.

This means that if you’re going to be doing a criterion where you have to accelerate out of a lot of technical corners or ride up punchy climbs, the best wheel will be a lighter rim with lower inertia.

Aluminum wheels, on the other hand, can be fantastic. They can be as light as 1.3 to 1.4 kilograms, which isn’t much. If you choose a wheel like the Vision Metron 30 Tubular, you can save an additional 300 grams. That doesn’t sound a lot but when you’re stamping on the pedals or smashing up a climb, that is a real difference.

Aerodynamics

The biggest advantage of carbon rims is aerodynamics. You go faster for the same effort when you use deep-section aerodynamic wheels. Now how much faster a deep-section wheel is? Well, either loads or not very much depending on your perspective. Many different independent sources have studied this extensively. In general, using a deeper wheel over a shallower wheel saves around 30 seconds over 40 kilometers at 40 kilometers per hour. If you’re looking to become more aerodynamic and faster, carbon wheels are the way to go.

Braking

With regards to braking, if you’re running rim brakes, then aluminum rims are accepted as having better braking performance than carbon rims. This is especially noticeable when it is wet. Aluminum rims also dissipate heat better than carbon rims. If you’re a heavier rider, or if you’re dragging the brakes down a steep descent, it is possible to delaminate a carbon rim.

Manufacturers responded by texturing the rim and improving the resin. However, if you’re using disc brakes, the material of your rim doesn’t matter because all of the braking is done at the disc. Another advantage is reduced rim wear. So, using your rim brakes can cause rim wear, which can be costly on a carbon rim because, well, it can’t really be repaired.

Crosswinds

Deep-section wheels can be twitchier in cross winds, which is a common complaint. I have ridden deep sections in a wide variety of conditions. And I can assure you that it is not as serious as many people believe. It’s something that’s gotten a lot better with more modern rim shapes. It’s more of a problem if you’re a smaller, lighter rider like me, but I’d go with an all-around wheel. So the 40-millimeter Vision I have is ideal. It’s light, it’s aerodynamic, and it just does everything. It’s not going to be too twitchy in the crosswinds.

Stiffness

Stiffness is an important factor in having a stiff set of wheels. When you’re pounding the pedals, the last thing you want is a flexy, inefficient, and spongy-feeling wheelset. Furthermore, having a stiff pair of wheels in the corners is a lot nicer and more confidence-boosting. It’s important to point out and it’s a big but, that you can make a really stiff set of wheels out of aluminum or carbon. The only difference is that the aluminum wheels will most likely be a little heavier.

How Much Faster Are Carbon Wheels?