Advantages and disadvantages of carbon wheels on gravel bikes and how to choose

Advantages and disadvantages of carbon wheels

First, let’s look at the advantages and disadvantages of carbon wheels for general sports bicycles.

Advantages

There are three advantages of carbon wheels: high rigidity, light weight, and aero.

Carbon can be manufactured lighter and more rigid than aluminum, which is commonly used in road bike and MTB wheels, due to its ease of fabrication. The lighter the wheel as a rotating body, the lighter the ride, and the higher rigidity prevents the rim from flexing, efficiently converting pedaling power into propulsive force.

In addition, because carbon is light and can be molded with a high degree of freedom, deep rims (high rims) can be used to create an “aerodynamic effect” that reduces aerodynamic drag.

For these reasons, not only professional racers but also hobby riders are increasingly using carbon wheels.

Disadvantages

The disadvantages of carbon wheels are "price and weakness to single-point blows.

First, carbon wheels are manufactured by hand because the technology for manufacturing by machine has not been established. Therefore, the price is higher than that of aluminum wheels.

However, the price of carbon wheels has been on a downward trend in recent years, and carbon wheels of the same quality as the top grade wheels of a few years ago can be purchased in the 100,000 yen range, which is gradually becoming easier to obtain.

Next is the weakness against single-point blows. Carbon has an image of being “fragile,” but in fact, in terms of strength, it is a harder material than aluminum, which is a flexible metal. However, carbon wheels are made by solidifying carbon material with resin such as epoxy, so when a single point is hit, the resin cracks instead of the carbon.

Once cracked, the cracks can spread like leaves and branches, making carbon wheels a difficult part to handle.

Advantages of carbon wheels on a gravel bike

Weight can be reduced by several hundred grams.

Carbon wheels for disc road use tend to be heavier than those for rim brake use, but even so, deep-rim carbon wheels can weigh in the 1,500g range, and higher grades can weigh in the 1,300g range.

Aluminum gravel wheels also weigh in the 1,500g range, but there are few models that are lighter than 1,500g, and since they are narrow rims, the advantage of carbon wheels is that they "can also provide an aero effect and reduce weight.

Since most complete gravel bike wheels weigh around 2,000g front and rear, the weight of the wheels alone can be reduced by nearly 500g.

Easier to maintain high speed cruising

Gravel bikes are inevitably heavier when cruising on flat pavement due to their large tires, making it difficult to ride long distances.

By using carbon wheels, the bike becomes stiffer and more aerodynamic, making it easier to maintain high speed cruising on flat paved roads.

If you have a long distance to ride on your own on paved roads until you get to the gravel section, carbon wheels will be of great benefit.

Disadvantages of mounting carbon wheels on a gravel bike.

There is a risk of cracking on unpaved roads.

Even though carbon wheels have a “risk of damage if cracked,” there is not that much risk of cracking on paved roads unless you fall off or knock over your bike.

However, it is a different story on gravel, where you are more likely to hit stones and branches. Frequent riding on gravel is enough to deform even aluminum rims when hit by foreign objects, so riding on gravel with carbon wheels means a higher risk of cracking than on paved roads.

Pricey.

Even just a disc brake wheel is more expensive than a traditional rim brake wheel, but a carbon disc wheel is difficult to obtain for $1,000 new.

For aluminum wheels, there are models that cost about $400 and weigh about 1,700g, but for carbon wheels, you need to budget at least $1,000 to $1,500d.

Considerations when choosing carbon wheels for gravel bikes.

Choose wheels that are ASTM Standard “Condition 2” or better.

Bicycle wheels have a condition grade for use as defined by ASTM, an international standards organization. For gravel bike use, ASTM Condition 2 (paved road + clean gravel road) is the equivalent.

Focus on the warranty.

Carbon wheels may offer free repair/replacement or discounted new replacement when a wheel is damaged by cracks or other problems, depending on the manufacturer.

For example, ZIPP wheels, which are part of SRAM, have a “lifetime warranty” and will repair or replace any wheel that is damaged or malfunctions during normal riding at no charge to the first owner.

By choosing carbon wheels from a manufacturer with such a generous warranty, you can avoid financial damage if you should damage them.