What is a bicycle rim?

A bicycle rim refers to the edge of the wheel. A bicycle wheel consists of three parts: the rim, spokes, and hub, and it is a very important component for attaching the tube and tire. It might be easier to understand it as the part where the brake pads make contact when you pull the brake lever.

Types of bicycle rims

There are three main types of bicycle rims.

Clincher rims

Clincher rims are the most common type of rim and are often found on road bikes and city bikes. This type uses a tire that hooks onto the rim. It requires a separate inner tube. Due to their widespread use, there is a wide variety of tires available, puncture repair is easy, and running costs are low. Due to their structure, they tend to be heavier as they require strength, and they are also more prone to punctures compared to other rims.

Tubular rims

Tubular rims are primarily used in professional cycling, such as in races. They involve attaching a tubular tire to a tubular-specific wheel. Tubular tires have an inner tube sewn inside them and are secured to the rim using an adhesive called rim cement. Tubular wheels are characterized by their light weight and puncture resistance. However, since they are designed for professional sports, both the rims and tires are expensive, and repairing a puncture is difficult, usually requiring a tire replacement.

Tubeless rims

Car and motorcycle tires, for example, are tubeless. Tubeless rims are relatively new and are mainly used on off-road bicycles. They are highly puncture-resistant and often compatible with clincher tires, offering the flexibility to choose based on preference and use. Wheels tend to be heavy, and lightweight options are expensive. Mounting the tire requires some skill and practice.

Carbon bicycle rims

Carbon rims are overwhelmingly lighter than aluminum rims. Their disadvantages include weakness to heat and strong impacts, such as deformation due to heat from frequent braking on downhills, or damage when hitting a bump during high-speed cruising. Carbon rims are expensive. However, their prices have been decreasing in recent years, and performance has been improving year after year. They are now becoming affordable for general users.

Aluminum and stainless steel bicycle rims

Aluminum is the most popular material for bicycle rims. Some types have only stainless steel spokes. They are easy to use, and aluminum rims have an advantage over carbon rims in terms of braking performance. Since they are easier to manufacture than carbon rims, they are also cheaper, and due to their high adoption rate, there are many choices available.

Bicycle rim size

If the rim size changes, the compatible tire width also changes. This also affects ride comfort and cornering grip.

Bicycle rim width/height

While rim width standards vary by manufacturer, generally, rims under 15mm are called narrow rims, and those between 17-19mm are called wide rims. You can mount the same size tire even if the rim width is different. However, wide rims will be wider, and narrow rims will be slightly taller. Wide rims are said to be better for city riding because the tire's contact patch is closer to a circle, which reduces rolling resistance. Narrow rims offer superior tire grip in cornering and stability at high speeds.

Regarding rim height, rims with low (shallow) height are called low profile. They are light to start pedaling and advantageous on climbs. However, because the rim is thin, rigidity is low, and to compensate for this, there tends to be more spokes, which increases air resistance. There are also types with fewer spokes, but they have weight limits.

Rims with high (deep) height are called aero rims or deep rims. Deep-rim wheels, which originated from indoor track racing, make it easy to maintain speed, so they excel in high-speed cruising on flat terrain. Since the rim height is deep, the spokes are short, and there is no flex when pedaling, allowing for a firm pedaling feel.

Extremely high rim heights have the disadvantage of being susceptible to crosswinds. As the rim height increases, the wheel becomes heavier, and it receives wind from a larger surface area, making it easy to lose balance and unsuitable for climbing.

Bicycle rim replacement

Rims wear out due to friction with brake pads and impacts during riding. As a guideline, if you have ridden 20,000 km, or if you feel a bumpy sensation when touching the part where the brake pads contact, it's time for a replacement.

Here are the 4 steps to replace only the rim:

1. Remove the tire and tube from the wheel (and sprocket if it's the rear wheel).

2. Remove the spokes from the old rim.

3. Attach the spokes to the new rim.

4. True the wheel.

Let's look at them in order.

1. Remove the tire and tube from the wheel (and the sprocket if it's the rear wheel).

To remove the spokes, you need to remove the tire and tube (and the sprocket for the rear wheel).

2. Remove the spokes from the old rim.

Use a spoke wrench or a flat-head screwdriver to remove the spokes. At this time, it's a good idea to secure the spokes with string or tape to prevent them from coming loose.

3. Attach to the new rim.

Attach the spokes removed from the old rim to the new rim in the reverse order of removal.

4. Truing the wheel

Once the spokes are attached, the work is not finished; you need to perform a process called "truing." A wheel maintains its perfectly circular shape by the tension of all its spokes. If you don't true the wheel, some spokes will be subjected to excessive load, causing them to deform or break easily. Rim replacement requires a special "truing stand." Therefore, it is not practical for individuals to replace it themselves. You will likely pay an additional labor cost of 7,000 to 10,000 yen at a shop for replacement.

Bicycle rim price

The price of rims varies depending on the material and product grade. Carbon rims range from 25,000 yen to 120,000 yen, while aluminum rims range from 2,000 yen to 80,000 yen.

Cleaning bicycle rims

When riding in rain, snow, or dusty environments, tires kick up sand from the ground. If sand adheres to the brake pads and you apply the brakes, the rim will get scratched. Aluminum is a relatively soft metal, so it might be better to say it gets worn away. Carbon, being a resin, will also be worn away even more.

In addition, the rim gets dirty with black residue from contact with the brake pads, and if left as is, the braking performance will deteriorate. Regularly wiping the rim with a cloth and cleaner not only improves braking effectiveness but also extends the life of the rim.

Bicycle rim painting

Painting the rims can dramatically change the look of your bicycle. Since the difficulty is low, many people do DIY painting with lacquer spray. When painting rims, be aware that the weight will increase by the amount of paint. Also, do not paint the parts that come into contact with the brake pads.

Top 3 Recommended Bicycle Rims for 2020

40mm Disc Brake Bicycle Rims

The 2020 series features a wider wheelset compared to standard wheels. This further enhances stability during high-speed cruising. Available with rim heights of 35cm, 40cm, and 50cm, the 40cm rim is highly recommended for those who seek both speed and stability.

Folding Bicycle Rims - Minivelo Rims

Minivelo rims made with T700 carbon. Affordably priced, this product is perfect for those looking to experience the benefits of carbon by starting with carbon rims.

Bicycle Rim DT AERO50

You will definitely feel the difference compared to your previous wheels. The heat resistance has also been improved, with the Aero series capable of handling temperatures up to approximately 149 degrees Celsius, compared to approximately 115 degrees for the FL series. It uses DT SWISS hubs, and two types are available; if you want to maximize lightness, choose the 240S.