Introduction
A higher-end wheelset is one of the most significant performance upgrades you can make to your bike. When it comes to choosing between carbon wheels and alloy (aluminum) wheels, the decision of what to get isn’t always straightforward. Each of the two has its own benefits and drawbacks. In this guide, we’ll compare carbon vs alloy wheels in terms of performance, durability, comfort, and price, so you can make a more informed decision.
Weight
Everything else being equal, carbon wheels are typically lighter than alloy wheels given the same depth. This makes them the preferred choice for those who like climbing, accelerating, and having a light bike. Wheels and tires are the most effective place to lose weight from your bike, since the weight is rotational. Rotational weight is different than say, your frame in that when you want to get up to speed, it takes more energy to rotate a wheel, especially where forces are strongest, at the rims and tires.
While alloy wheels can be made light, they are often limited to shallow rim depths, meaning they lose out on aero benefits. In general, stock alloy wheels are in the 2kg range. Advancements in carbon rims and spokes have allowed for some superlight climbing wheelsets, such as the Particle RCX33 Ultralight and GCX30 Ultralight. These wheelsets are significantly lighter, weighing just 1030 and 1020 grams respectively, making them roughly 1kg lighter than most stock alloy wheelsets.
Furthermore, it is not possible to make lightweight alloy road or gravel wheels that are anywhere as aero as carbon wheels can be. We will get into the aeo benefits in the next section
If you do a lot of climbing either on mountains or in the hills, then it is recommended to consider a carbon
Aerodynamics
Perhaps even more important than weight for performance are the advantages to be had for upgrading to aero wheels. Carbon rims allow for deeper, more aerodynamic profiles without adding excessive weight. This is why nearly every pro rider uses deep-section carbon wheels regardless of the terrain.
Alloy rims rarely exceed 30mm depth because weight becomes prohibitive, so they can’t match carbon’s aero advantage. While having a shallow rim doesn’t make much difference when climbing, it is a disadvantage when riding on the flats and downhills, where most riding takes place. It is thought by many that the ideal rim depth for an aero wheelset is 50mm, since it is significantly more aero then shallower wheels, but is not too deep as to be affected by crosswinds. Some examples of deep section carbon wheels are the RCX50 Ultralight, which weighs just 1100 grams, and the GCX50 Ultralight, which weighs 1120 grams.
For riders looking for a serious aero upgrade, look no further than a deep section carbon wheelset. They will give you a much bigger aero advantage than choosing an aero frame or aero handlebars.
Stiffness and Ride Quality
Carbon wheels are generally much stiffer laterally, which translates to snappy acceleration and precise cornering. This is partially due to the fact that carbon wheels are deeper and because carbon fiber as a material can be made far stiffer than alloy rims. This can offer much better power transfer, improving efficiency.
Alloy wheels on the other hand tend to offer more compliance and comfort, all else being equal. With newer 4th generation carbon spokes, however, things are changing. They offer significant improvements when it comes to ride quality. They also reduce weight significantly, weighing just 2.1 grams each.
In general however, if you want to have more comfort, the difference between carbon and alloy wheels is nowhere near the difference between choosing a narrower and a wider set of tires. Most of the difference in compliance you feel when out riding actually comes from using wider tires. Modern carbon rims allow for wider tires. Internal widths on modern wheelsets like the RCX and GCX series have either 21mm or 25mm internal widths. These wider internal rim widths allow for tires that are significantly wider. Many road riders today have even started running 32c-35c tires, making for a very comfortable ride.
Durability and Impact Resistance
While it is assumed that alloy rims are stronger than carbon wheels, the truth is not so simple. The fact of the matter is, carbon wheels are now ubiquitous in pro cycling. In order for carbon wheels to be ridden in pro cycling, they have to pass the UCI Vertical Impact Test. At Particle, all of our wheels have passed our standard 90-Joule vertical impact test, more than twice that required by the UCI.
When rims do fail however due to a strong enough impact, carbon rims will crack while most alloy rims will bend, and both will need to be replaced. Understand that not all wheels are created equal. Some carbon rims are strong, and some are relatively weak. The same is true with alloy rims. That is why it is good to not exceed wheelset weight limits.
Braking Performance
As far as braking goes for rim brake bikes, in general alloy braking surfaces are far superior to carbon braking surfaces, especially in wet conditions. Furthermore, rim brake tracks on carbon rim brake wheels tend to get hotter. The truth is that not all carbon rim brake tracks are created equal, with lower quality ones failing at lower temperatures.
No matter what kind of riding you do, it is recommended to follow best braking practices, especially when descending to prevent brake tracks and disc brake rotors from overheating.
Cost and Value
As far as cost goes, the truth is that carbon wheels are more expensive than alloy ones. This partially comes down to manufacturing costs. Carbon wheels can range from several hundred dollars to several thousand dollars. Alloy wheels tend to start from a few hundred dollars with some exceeding $1000.
In general, most entry-level and even many mid-level road, gravel, and mountain bikes comes with alloy wheels are standard. This is to cut costs and reduce the overall price of the bike. In fact, one of the best upgrades you can make so your bike to make it high performance is carbon wheels, but for the most part, they are prohibitely expensive.
Particle’s aim is to change the idea that quality whels have to be expensive. Our high-performance, carbon spoke carbon wheels start at less than $1000 for some seriously aero and light wheels built with the best quality rims, hubs, bearings, and spokes available.
Which should you choose?
For people who are just getting into cycling, the stock alloy wheels on your bike may be good enough. They are good for beginners and are less expensive in general. If you find you really like cycling and want to take things to the next level, the best place on your bike to make an upgrade is your wheels. Quality carbon wheels can offer a significant improvement in aerodynamics, stiffness, and weight.