The Ultimate Guide to Road Bike Wheels

Road Bike Wheelset Structure

Hub: The wheelset revolves around the hub located in the center. The hub on the rear wheel has a ratchet mechanism (unless you are riding a fixed gear bike), which allows the bike to coast freely, but drives it forward on demand when you pedal. The hub contains bearings inside, and the axle rotates on the bearings. It is this axle that secures the entire wheelset to the bike. It also allows you to install brake discs (if designed for disc brakes).

Spokes: Metal wires or sometimes carbon fiber that connect the hub to the rim. The number of spokes and material selection for each wheel are important. In most wheelsets, the spokes are under tension, which is what gives the wheelset its structure.

Nipples: At the rim end (usually), the spokes are screwed into a special nut called a nipple. By adjusting the spoke tension on the nipples, most wheelset wobbles can be corrected.

Rim: The rim is located on the outside of the wheelset, used to hold the tire and provide support for the braking surface of bikes with rim brakes.

Types of Road Bike Wheelsets

Just as road bikes are now increasingly categorized according to their use (racing, endurance, aerodynamics, gravel, etc.), wheelsets also fit into similar categories.

Knowing your riding style and the goals of upgrading your wheelset can help you quickly filter out suitable options.

Climbing Wheelsets

Hunt's 991g Hill Climb SL is a wheelset specifically for climbing

Weight is most noticeable when climbing, so wheelsets suitable for climbing are usually designed with light weight in mind. These wheelsets typically have shallow rim depths and fewer spokes.

Another benefit of this type of wheelset is reflected in the ride quality. Generally, the deeper the rim shape, the rougher the ride feels—so climbing wheelsets are often more comfortable.

If a wheelset weighs less than 1,500 grams and does not claim to have aerodynamic properties, it can usually be classified as a climbing wheelset. When budget is not a constraint, the weight of an ultra-light climbing wheelset should be between 900 grams and 1300 grams.

Mid-Depth Aerodynamic Wheelsets

Rim depths of 35 to 50 mm are considered mid-section aerodynamic wheelsets

Aerodynamic wheelsets have quickly become a popular choice for adding speed advantages without extra effort and creating a "more professional look". Aerodynamic wheelsets typically have deeper section rims, with a rim depth of around 35 mm being a typical starting point. They are usually made of carbon fiber, although alloy options are also available, and most are designed for disc brakes.

In recent years, with the advancement of aerodynamic design, this type of medium-depth wheelset has become increasingly popular. Compared to the high-profile wheelsets mentioned later, they achieve a better balance between lightweight, riding comfort, and aerodynamic performance.

High-Profile Aerodynamic Wheelsets

Rims of 50 mm or deeper are considered high-profile

When speed is a priority, high-profile rims of 50 mm or deeper can potentially cut through the air with less aerodynamic drag.

However, the extra depth can cause problems when riding in strong crosswinds and often adds weight, which is why medium-depth wheelsets have become a popular compromise outside of time trials and fast sprints. Riders who race on aerodynamic wheelsets often have a set of training wheels for use outside of races.

Training/Winter Wheelsets

Daily training wheelsets should be able to withstand daily wear and tear

While speed, low friction, and low weight are priorities for racing wheelsets, training or "daily" wheelsets must be durable and able to withstand impacts.

For rim brake bikes, the brake surface of the rim will gradually wear down with use, especially during winter riding. Therefore, equipping a set of cheap training wheels can effectively protect your expensive racing wheels and extend their lifespan. Custom handmade wheelsets—where replacing spokes and rims is relatively cheap and easy—are a good option (see below for more information). Other options are entry-level wheelsets from major brands, where parts are not too expensive to replace.

For this type of use, expect the wheelset to weigh between 1500g and 1800g and be reasonably priced. Entry-level wheelsets may weigh 1900g or more.

Tire Types

There are three types of tires for road bikes, each requiring a specific rim.

Clincher Tires

Most road wheelsets are designed to use clincher tires, many of which are also tubeless-ready

The term "clincher" refers to the standard tire that uses a separate inner tube to hold air, which pushes the tire bead into the hooked rim to secure it in place.

This is the most common type of wheelset on road bikes. Usually, if the tire type is not mentioned, it can be safely assumed to be a clincher.

Tubeless Tires

Tubeless tires are used with sealant

Tubeless technology has been around in mountain bikes for a long time, but now it is making a serious impact on road bike wheelsets.

As the name suggests, tubeless tires do not require an inner tube—just like car tires. Instead, sealant and a tubeless-ready rim are used to create what is essentially an airtight vacuum system.

Manufacturers claim that removing the inner tube can reduce rolling resistance, eliminate the risk of punctures at low inflation pressures, and the sealant can seal small holes while riding.

Tubular Tires

Tubular tires need to be fixed to the rim with special glue, so it's best to ask a professional mechanic for help

Tubular tires (often abbreviated as "tubs") are the oldest type of road bike tire. They typically consist of an inner tube sewn into a fully enclosed tire casing, which must then be glued or taped to a compatible rim. Tubeless tubular tires also exist (i.e., airtight tubular tires without an inner tube), but these are relatively uncommon.

The main advantage of tubular tires is that tubular wheelsets can be relatively light. This is because the material used to make rims that can withstand the high internal pressures of clincher or tubeless tires adds considerable weight.

Tubular tires can also be ridden flat for short distances, which can be advantageous in races.

For these reasons and tradition, tubular tires and wheelsets still dominate the professional racing scene (where riders don't have to fix their own punctures or pay for new tires) and climbing events, although this is starting to change.

Road Rim Materials

There are two common types of materials for modern wheelsets: carbon fiber or aluminum alloy

Aluminum usually appears in any wheelset below £800 / $1200 / $1500 AUD, with carbon fiber wheelsets typically priced higher than this.

Just like road bike frames, carbon fiber has become the standard material for performance racing wheelsets, where stiffness, weight, and aerodynamics are priorities.

Aluminum still sets the benchmark for braking performance for aluminum alloy braking wheelsets, especially in wet conditions. In recent years, carbon fiber rims have made great strides in this area. However, this is not an issue if your bike has disc brakes.

Road Wheelset Diameter

The standard road bike wheelset size is 700c, named after the approximate metric measurement of the wheel diameter including the inflated tire.

Some brands will specify 650b wheelsets on smaller frame sizes to improve their geometry, and 650b is another important option for gravel bikes, but the vast majority of modern road bikes use 700c wheelsets.

If you look closely at your road bike tires, you may see numbers such as 23-622 or 25-622. These numbers are the International Tire Size Standard, where the first number indicates the tire width (23mm, 25mm) and the second series of numbers (622 in this case) indicates the Tire Bead Seat Diameter (BSD) designed to fit 700c rims.

Road Rim Width

Rim width affects the profile of the tire after inflation

While the 622mm wheel diameter is an industry standard, the width of the rim is not.

Recently, there has been a trend towards wider rims, as they offer greater tire volume and a more robust wheelset, providing a more comfortable ride, better bike control, lower rolling resistance, and potentially fewer punctures.

What can be confusing is that different brands use different standards for marking rim width, some marking the external width and others the internal width.

Looking at the internal width, anything less than 14mm is considered very narrow, 20mm and above is wide, and anything in between is sufficient for common 25mm tires, although they can also sit comfortably on wider rims.

Internal width is important because it affects the tire profile. Narrow internal width rims give the tire a "light bulb" cross-section, which can reduce the contact patch and reduce grip, while wide internal width rims flatten the contact patch and increase its size.

For those who race, wider rims have been shown to be more aerodynamic because the rim can transition more smoothly to the tire. This is because wider rims can help form a smoother airfoil shape with wider road tires.

Axle Size

If your road bike was manufactured in the last 20 years and has alloy brakes, it most likely has a 130mm wide rear axle (written as 130mm QR or 130 × 9mm) and a 100mm (100 QR or 100 × 9mm) front axle.

However, the introduction of disc brakes has greatly confused this, and for a while, there were multiple standards for bikes with disc brakes, most of which borrowed thru-axle quick release designs from mountain bikes.

If you are an earlier adopter of road disc brakes, the safest way is to consult the specifications provided by the bicycle manufacturer to confirm the specific standard used by your vehicle.

That said, the industry seems to have finally settled on a unified standard for road disc brake bikes: 12mm thru-axles with 100mm front and 142mm rear spacing.

Freehub Body and Drivetrain Compatibility

The freehub body located on the right side of the rear hub is the part used to secure the drivetrain cassette and drive the rear wheel. While most 11-speed designs are now backward compatible, it is important to match the freehub body to your drivetrain brand.

Shimano/SRAM 11-speed Freehub Body

The freehub body on DT Swiss's GRC1400 rear wheel is compatible with Shimano 11-speed, SRAM XD, and 12-speed road compatible SRAM XDR standards

However, not all wheels offer such wide compatibility.This spline system has not changed much in the past 20 years, except that 11-speed requires a wider freehub body. Shimano-compatible 11-speed freehub bodies typically include a spacer that can be used for 8-speed, 9-speed, or 10-speed cassettes.

SRAM 11-speed cassettes use Shimano's spline system, so they are cross-compatible. The exception is the newer SRAM cassettes designed for its XD drive (more on that below).

Shimano 12-speed

This is Shimano's 12-speed Micro Spline cassette, which is not compatible with 12-speed Shimano road cassettes

Shimano's new 12-speed cassettes and freehub bodies also use a new spline pattern with smaller, more splines, although it is different from the Micro Spline format used in 12-speed MTB cassettes. The new design means that 12-speed Shimano road cassettes are backward compatible with 11-speed cassettes, but you cannot install an 11-speed cassette onto a freehub body with the new splines.

Campagnolo Freehub Body

Campagnolo freehub bodies have very different diameters and splines than Shimano/SRAM. If you use a Campagnolo drivetrain, make sure the freehub body matches. Many aftermarket wheelset brands sell freehub bodies as replacement parts—so it is possible to switch a Campagnolo wheelset to Shimano or vice versa (Shimano-branded wheelsets are a key exception).

That said, an 11-speed Campagnolo freehub body can be a perfect match for a Shimano or SRAM 11-speed drivetrain (or vice versa), so in this case, there is no need to replace the freehub body.

When Campagnolo moved to 12-speed, it simply narrowed the width of the 12-speed chain and cassette to fit the existing 11-speed Campagnolo-compatible freehub body.

The latest Campagnolo wheelsets use a new standard called N3W. This uses a shorter freehub body that is compatible with Ekar Gravel kits. Campagnolo offers an extender that can be installed on the N3W freehub body so that it can also accept its road freehub bodies.

SRAM XD & XDR driver

The XD driver is SRAM's solution to allow the use of gears smaller than 11t

The increasing popularity of 1× and 12-speed drivetrains (and the subsequent need for gears smaller than 11t) has created problems for cross-compatibility charts.

SRAM's solution is the XD driver for off-road and the XDR driver for road use, which are essentially just new freehub body standards that allow for a minimum 9t cassette.

Like tubeless tires and disc brakes, this technology was originally born in mountain bikes and then entered road wheelsets with the introduction of SRAM's AXS groupset. The XDR freehub body is slightly wider than the XD, so you can mount an MTB cassette on an XDR body (with a spacer), but not vice versa.

Freehub Body Ratchet Speed

One often overlooked feature of a freehub body is the ratchet speed, also known as the number of engagement points or the engagement angle. Hubs typically have no fewer than 18 engagement points per 360-degree rotation, but hubs that offer more engagement points can provide a faster acceleration and cornering feel. Typical values are between 24 and 48, but some hub designs are much higher. Some brands quote engagement points, while others tell you the hub's engagement angle, which is 360 degrees divided by the number of engagement points.

Road Wheelset Brakes

Rim brakes have long been the standard on road bikes. But as mentioned above, disc brakes, a technology proven on cars, motorcycles, and mountain bikes, have quickly been adopted by road cyclists. Disc brakes add another factor to the decision-making process.

Disc Brake Road Wheelsets

Disc brakes are now standard on performance road bikes

Disc brake wheelsets are characterized by having a wheelset with a mount for installing a brake disc.

Because these brake discs exert tremendous force on the wheels when braking, disc brake wheelsets typically have a higher spoke count, which adds a bit of weight.

On the other hand, the rims on disc brake wheelsets can be lighter and more aerodynamic because they do not need to also act as a braking surface.

It is worth noting that installing disc brakes on a road bike is not as simple as changing wheels; the frame and fork must also be designed to accept disc brakes.

When purchasing disc brake wheelsets, it is worth noting that there are two types of brake disc mounts: center lock and six-bolt.

Center lock is a spline system originally from Shimano and is more or less standard on road bike wheelsets. It can also be used with six-bolt brake discs by using an adapter. Six-bolt wheelsets can only mount six-bolt brake discs.

Rim Brake Road Wheelsets

Rim brakes are now mainly used on entry-level road bikes

Many road bike wheelsets are still designed for use with rim brakes, which means the rim must provide a consistent braking surface.

This is why premium aluminum rims claim to offer a “machined” surface, which typically guarantees a uniform braking surface.

Over time, braking in gravel conditions will wear down not only the brake pads but also the rim. A worn brake track can be dangerous because the high pressure of road tires can cause the rim to crack and explode. Look for a small dent or groove on the rim surface—this is a wear indicator. When it starts to disappear, it's time to replace the rim or wheel.

Carbon fiber rim brake rims often perform poorly when braking, especially in wet or extreme conditions, such as long, steep mountain descents, requiring dedicated brake pads. Keep this in mind if you are considering using carbon fiber wheelsets for everyday use or switching between carbon fiber and alloy wheelsets, as you will also need to change brake pads.

Spokes

Spokes connect the hub to the rim. Generally, wheels with a higher spoke count are stronger and more durable, but this comes with weight and a slight aerodynamic penalty.

Typically, spokes are made from a stainless steel wire that is cold forged and then threaded. Some high-end wheels may use spokes made of aluminum, carbon fiber, or even titanium.

Proper spoke tension is critical when it comes to assembling a quality wheelset. Too loose, the spokes may loosen, and the constant bending will eventually cause the spokes to break or the rim to crack. Too tight, and the risk of the rim cracking at the spoke connection point or the nipple failing increases.

Complete Wheelsets vs. Custom Wheelsets

The question of whether complete wheelsets or custom wheelsets are better has always been a topic of debate among cyclists.

Confusingly, complete wheelsets are actually often at least partially assembled by hand. However, the key difference is that complete wheelsets are assembled to precise specifications and you can buy them as off-the-shelf items, often with proprietary spoke and rim designs.

Custom wheelsets take a more classic approach, where hubs, spokes, nipples, and rims can be purchased separately and optimally selected based on the rider's individual needs.

Generally speaking, race wheelsets are mostly sold as complete options. Large wheelset brands dominate this field due to their research, development, and marketing through sponsored teams. Custom wheelsets are often used for training, long distance, and everyday use. Of course, there are also examples to the contrary.

Used Road Bike Wheelset Buying Guide

As with buying a used bicycle, the intensity of use and condition of maintenance of the wheelset are the most important considerations when purchasing. The first step is to check if the wheelset is straight. Turn the wheelset to make sure it is not bent.

Rim:Check the wear on the braking surface (on rim brake wheelsets), which should be flat and free of dents. Check for any nicks, then check the entire rim for cracks, especially around the spokes.

Spokes:Check that all spokes are straight and free of dents or scratches. Squeeze two spokes at a time—all the spokes on the right side should feel roughly the same tension. Now do the same on the left side, which should feel similar. Unevenness is a sign of a bent rim, as the rim is held in shape by spoke tension.

Hub:Grab the hub axle and turn the wheelset. The bearings should turn freely without any resistance or stuttering. Check that the freehub body rotates and engages when rotating forward. Also, be sure to double-check that the freehub body is compatible with your kit (as described above).

Wheelset Glossary

• Axle: The axle connects to the dropouts of the frame and fork, and the wheelset rotates around the axle. Axles on road bikes are generally hollow.
• Bladed spoke: A flat spoke designed to reduce drag. Bladed spokes are common on high-end wheelsets and also help provide an edge for tools to grab, allowing for higher spoke tension. Top spoke brands DT Swiss and Sapim both claim that their best bladed spokes are not only the lightest option, but also the strongest and most durable.
• Butted spoke: A process that makes the center of the spoke thinner than the outer parts. When done correctly, this can improve durability and reduce weight. Double butted means two different thicknesses, and triple butted means three different thicknesses.
• Cartridge bearing: In this system, the bearing is contained in an all-in-one housing that has ball bearings as well as inner and outer races. The outer race is press-fit into the wheelset housing, while the axle contacts the inner race. These items are considered disposable, with the old ones being knocked out and the new ones pressed in.
• Centrelock: A Shimano pawl system for mounting brake discs to wheelsets.
• Clincher: The most common type of tire system on road bikes. Here, the bead on the tire locks with the flange on the rim. Non-tubeless clinchers use an inner tube to maintain air pressure.
• Cup and cone bearing: Cup and cone bearings are an alternative to integrated bearings. It is most commonly found on entry-level wheelsets and all wheelsets sold by Shimano. These wheelsets have loose ball bearings that run on permanent outer bearing seats with tapered inner seats that can be adjusted.
• Dish: The relative position of the rim to the hub. In almost all frame designs, the rim must be perfectly centered above the wheelset.
• Double-wall rim: Refers to the internal cross-section of the rim. A single-wall rim has only one layer of material for the spokes to connect to and the tire to sit on, while a double-wall rim adds a layer of material that separates the two. This extra layer creates a box-type section, which greatly improves rim stiffness and wheelset durability.
• Freehub body: A mechanism on the rear wheel that allows the rider to coast or pedal backward without pedaling.
• Spoke flange: The part of the hub where the spokes connect.
• Spoke gauge: Refers to the thickness of the spoke. The most common is "14G", which usually equates to 2mm in diameter, and "15G" is thinner at 1.8mm. Thus, a "diameter spoke" has a single diameter, while the most common double-butted spoke has a 2/1.8/2mm diameter, sometimes referred to as "14/15G".