If you have been cycling for a while, you will see both professional and amateur riders riding high-end bikes with deep rims. Maybe you look at their wheels enviously, or you already have carbon wheels and you just have questions or are considering upgrading. We created this comprehensive guide to answer frequently asked questions about carbon fiber bicycle wheels. If you choose to upgrade the wheels of your bike, this guide will help you make an informed decision.

Why do bike wheels matter so much?

The wheel of a bicycle may be the most important part of a bicycle. They are constantly rotating and are the only point of contact with the ground when you ride. Therefore, they have a great influence on your riding performance, safety and comfort.

Background & History of Carbon Wheels

What is carbon fiber?

Carbon fiber originated in the aerospace industry. It is made of loose fibers composed of carbon atoms, which are then suspended in resin to form a solid material. Carbon fibers or carbon fibers are fibers having a diameter of about 5 to 10 microns and mainly composed of carbon atoms. Carbon fiber has several advantages, including high stiffness, high tensile strength, low weight, high chemical resistance, high temperature resistance, and low thermal expansion.

How is a carbon fiber wheel made?

The carbon fiber rim consists of two parts; carbon fiber and epoxy resin. When forming a carbon fiber wheel, the pre-impregnated carbon fiber sheet is placed in the mold. Prepreg is coarse carbon fiber impregnated with epoxy resin. Before the invention of prepreg, laying the original carbon fiber in place and then coating the carbon fiber with epoxy resin was a messy and difficult process. Prepregs make the manufacturing process cleaner and more feasible.

Once the prepreg carbon is placed in the mold, it is placed in the oven, where it undergoes a prescribed heating cycle, called a ramp cycle. The oven with mold starts at low temperature, rises to the set point temperature, and then lowers to the outlet temperature. Each stage has a predetermined time. If you are plotting a temperature graph over time, you will create a ramp shape, so it is called a ramp loop.

When the carbon fiber leaves the mold, it is a hard finished part. However, all epoxy resins have a so-called "glass transition temperature", that is, the hardened epoxy resin changes from glass back to liquid. When this happens, the carbon fiber object becomes soft and fails.

The design and selection of epoxy resin is crucial for carbon fiber rims. Most of the myths mentioned at the beginning of this article can be traced back to when carbon fiber rims were first manufactured in the 90s and early 00s. At the time, if epoxy resins produced brittle parts, they could only withstand the high temperatures required for braking heat. You can't find a resin that can produce durable rims that can withstand high temperatures.

Today, epoxy resin has made significant progress, and we can produce rims that are resistant to high temperatures and are more durable than aluminum.

When was the first carbon fiber clincher made?

Lew Composites launched the first all-carbon fiber clincher bead in 1998. The owner of the company, Paul Lew, is an avid triathlete. He wanted the same weight reduction and aerodynamic characteristics that carbon tubes can provide, but with the ease of use and versatility of a clincher tire.

When was the first carbon bike wheel used in a race?

In 1993, Heinz Obermayer and Rudolf Dierl developed a spoked wheel made of carbon, which immediately won the UCI professional competition when it was launched in 1994 Certification.

The Advantages of Carbon Bicycle Wheels

Are carbon bike wheels faster than alloy wheels?

If the alloy wheels and carbon fiber wheels have the same shape and weight, the aerodynamic benefits are the same. However, it is much easier to shape carbon into the desired shape than an all-alloy rim. Due to the construction method used, carbon fiber wheels are generally faster, especially on full carbon fiber rims. The all-carbon wheel has no carbon-aluminum combination, and the spokes are connected to the rim. In the aluminum+carbon wheel, the carbon fairing has holes through which the spokes pass. This allows the wheel structure to have a reduced Cda, so they are usually faster.

Carbon Wheels and Aerodynamics

Because carbon wheels are made with a mold, they can be produced in more complex shapes than alloy wheels. This tailoring allows for improved aerodynamics. While weight used to be king of all considerations, more recent studies show that aerodynamics play a more significant role than weight in terms of speed except when continually climbing steep gradients  of 12% or greater. If you only have a short section with steep grades, aerodynamics win. A wheel’s aerodynamics is more important than weight by a factor of 60:1.

Are carbon wheels more comfortable?

Carbon fiber as a material absorbs vibration better than aluminum wheels. Additionally, the construction of a carbon wheel produces a leaf spring effect in the sidewalls of the carbon rim. This is because the spokes connect to the internal diameter of the rim. On an Aluminum + Carbon rim, the spokes pass through the fairing and connect to the aluminum rim. This does not allow for the benefits of a leaf spring.

As a result, carbon wheels are more comfortable to ride due to their lower levels of vibration.

Please contact us(sales1@gofastbicycle.com) to discuss and provide you with customized services.