Carbon fiber wheels have become one of the most desired upgrades in cycling, both for mountain bikes and road bikes. Although their adoption in mountain biking has been slower, their success is undeniable, especially in high-end bikes. Their lighter weight and greater stiffness have been key factors for improving performance on technical routes and demanding climbs.
However, the trend has evolved, and more and more cyclists with mid-range bikes have opted to upgrade their equipment by incorporating carbon wheels. This decision aims to reduce the bike’s weight and optimize pedaling efficiency, both on mountain trails and long road rides.
If you are considering changing the aluminum wheels of your mountain or road bike for carbon rims, it is important to know their advantages and disadvantages before making a decision. Below, we analyze the pros and cons of this investment so you can choose the option that best fits your cycling style.
Advantage: they are lighter
This is the main advantage of a rim made from carbon fiber. It also multiplies its benefits as it is the largest moving component of the bike. This means that the weight saving, around 400 grams on average per pair, will be much more noticeable if you install carbon wheels than if you do the same with a handlebar, stem, or seatpost, which are smaller parts and not as crucial when moving the bike. On the other hand, the weight of the rotating wheels also increases inertia, which must be managed when descending or reduced with your own strength when climbing. Controlling or reducing inertia leads to an increase in energy expenditure by the cyclist. For this reason, reducing the weight of the wheels will not only allow you to ride faster, but also save energy.
Advantage: they are stiffer
The degree of structural stiffness of a carbon wheel for mountain bike is greater than that of an aluminum one, using less material. And in a component as important for a bicycle as the wheels, its beneficial effects are multiplied, just as with weight. This increase in stiffness translates into better handling sensations. This property allows the inertia to remain contained in the wheel and not dissipate as much as with aluminum wheels, resulting in less flex. Thanks to this, you'll feel more of the steering movement in your hands, almost as an extension of them. Likewise, a stiffer and lighter wheel is easier to control when cornering, accelerating, and climbing.
Advantage: carbon is more resistant
At this point, it's time to debunk the widespread and false myth that carbon wheels are less resistant than aluminum ones. The very composition of the material used, carbon composite (the same used to make bicycle frames), a mixture of fibers and synthetic resins, increases the bonding of the different carbon layers that make up the piece. This results in a composite material that is very hard, rigid, and stable at high temperatures, capable of dissipating the force of an impact (such as from rocks, landing jumps, or crashes) more effectively. In this video from the structural engineering company Ager, you can check and draw your own conclusions about the resistance of carbon composite when subjected to high-intensity impacts compared to other materials, such as aluminum or steel:
Drawback: they are more difficult to repair
The aspect that may have falsely fueled the myth of carbon's fragility for mountain biking is precisely the type of breakage carbon experiences. To begin with, remember that it is much more difficult and uncommon for a carbon rim to be damaged by an impact compared to an aluminum one. But the truth is that, once broken, it is much harder to repair, and in most cases becomes unusable. Due to its ultra-rigid and low-density properties, carbon cracks, splinters, or breaks, while aluminum only dents, allowing it to continue being used (although its performance will no longer be the same and it should be repaired). This aspect is one of the few drawbacks offered by carbon wheels for mountain bikes. Due to the nature of the terrain, they are more exposed than road wheels to the impact of external elements, especially in the more extreme disciplines such as enduro and downhill, with the risk of breaking and making their repair practically impossible.
Drawback: their price is higher
Another barrier to buying a set of carbon wheels for mountain biking is their high price. They are still more expensive than aluminum ones, although in recent times some specific low-cost brands have entered the market using somewhat heavier composites. The average outlay for a pair of carbon rims, with their spokes and hubs already installed, is around one thousand euros. In contrast, aluminum wheels of a similar range are priced at less than half, around 400 euros. The complex manufacturing process of carbon components, which requires special molds that can withstand very high temperatures, as well as the higher cost of raw materials, make the final sale price higher.
Different wheels, each with its own use
The introduction of carbon fiber in mountain bike wheels It has been, without a doubt, a great advance for the discipline, due to the benefits previously explained. But the increase in sale price and the high cost to pay in case of breakage, which does not mean low resistance, are the two main barriers when deciding on them. That is why we recommend that you weigh these pros and cons and reflect on what purpose you want to install them for. If you are obsessed with weight and your intention is to promote a performance improvement, without a doubt the purchase of a set of carbon wheels is an investment that you will quickly recover. If you are a rider who loves radical routes or descents, your decision should be more considered. First, you should have a certain level and experience in this type of terrain, know how to control the bike on extreme slopes, drops, or tight corners. This is a quality that will ultimately prevent the rim from being exposed to impacts as much and at the same time allow you to enjoy the improvements of carbon. If you are a novice biker, it is more advisable to start with aluminum wheels. Repairs in case of receiving any impact are easier to carry out and cheaper. In addition, during riding, you will experience very acceptable feelings of control and handling on descents.