Upgrading your wheelset can transform the performance, handling characteristics and overall feel of your bike. The general consensus is that carbon wheels do a far better job of this than aluminium wheels. But do the pros outweigh the cons?
What was once reserved only for professional cyclists in the Tour de France, is now used by the majority of amateurs not only for racing but also training. The introduction of the carbon clincher revolutionised how we look at carbon road wheels. A high-end product used specifically for racing can now be used on an everyday basis thanks to an increase in practicality, choice and affordability. They’re lightweight, aerodynamic and improve the overall aesthetics of your bike but there are some drawbacks to consider.
Pros of carbon road wheels
Lightweight. One of the most significant pros to carbon road wheels is a reduction in weight as carbon fibre is a far lighter material than aluminium. This reduction in weight can have a huge impact on performance, especially when climbing. The majority of wheels on the market weigh around 1.5kg, some manufacturers produce wheelsets as light as 855g. The use of carbon fibre also makes it possible to build a deeper rim, which improves aerodynamics, while only fractionally increasing the overall weight of the wheel.
Aerodynamic. According to the wind tunnel data provided by manufacturers; deep section carbon fibre wheels are more aerodynamic and therefore faster than shallow wheels. There are real-world variables that wind tunnel testing struggles to replicate; riding in a bunch, directional changes (yaw angles) for example. These variable are however only a small part of the picture, on the whole, testing proves that high-profile carbon wheels provide an aerodynamic advantage.
Range of options. The rim depth of aluminium wheels is fairly universal, an increase in depth means a significant increase in weight when using a material such as aluminium. Because carbon fibre is so light manufacturers can develop a range of designs to suit every rider’s requirements. Between shallow rims and 100mm deep rims, there are options for almost every depth imaginable, not to mention 3-spokes, 5-spokes and disc wheels.
Aesthetically pleasing. Simply put, a set of deep-section carbon wheels makes your bike look more attractive. Many of us spend almost as much time ogling over our bikes as we do actually riding them, so why not spend a little money on making them more aesthetically pleasing?
Responsive. The lateral and radial stiffness of carbon wheels is often greater than that of aluminium wheels. This increase in stiffness, along with a reduction in weight and increase in aerodynamics results in a noticeable improvement in responsiveness. Whether you’re out the saddle on a climb, attacking a descent or sprinting for the line, carbon road wheels give a sharp, responsive feel.
Cons of carbon road wheels
Affordability. A set of carbon road wheels can put a serious dent in your wallet. Affordability has improved massively in recent years but the top end models can still set you back over £2,000.
Braking performance. The braking performance of carbon rim brake wheels is often not as responsive in the wet as it is in the dry. Advancements in rim and brake pad technology have improved but arguably aluminium wheels still perform better when braking in the wet. Disc brake models of carbon fibre wheels are available and are a potential solution to the problem as they deliver fantastic stopping power in all weather conditions.
Prolonged braking while descending on carbon wheels, especially in warm conditions, can lead to a build up in rim temperature which has an effect on braking performance.
Durability. Carbon wheels are designed to be incredibly stiff when a radial or lateral force is applied. This is what makes them so responsive when you accelerate out of the saddle and rock the bike from side to side. The drawback of using carbon composites is that wheels can be more expensive to replace if damaged in a crash.
Layup discrepancies. Layup discrepancies are one of the biggest drawbacks of the manual layup process and can lead to a decrease in both radial and lateral stiffness. Misalignments and overlaps can also lead to a slight imbalance in weight.
The drawbacks associated with carbon wheels are certainly worth taking into consideration. The initial cost is high and aluminium rims still perform better under braking in wet conditions. There are also aspects of the manufacturing process that could be improved to reduce layup discrepancies. That said, I still feel the pros far outweigh the cons. A reduction in weight, improvement in aerodynamics and increase in responsiveness all contribute to better performance when climbing, riding on the flat and accelerating.