When it comes to upgrading your bike’s components, one of the most often overlooked areas is the rims. Rims are an essential part of your bike as they support the tires. With so many options available in the market, it can be challenging to choose the perfect set of rims to replace your old ones. In this post, we’ll take a deep dive into the pros and cons of single wall vs double wall rims. We’ll cover rim strength, weight, performance, longevity, durability, and more. We’ll break down the differences between these two types of rims. Whether you’re a commuter, mountain biker, road rider, I hope this guide helps you choose the best rims for your style of riding.
What are Single Wall Rims?
The wall that is being referred to in the term ‘single wall’ rims is the spoke bed. Single wall rims have a spoke bed that is made from a single layer (or wall) of material. If you were to look at a cross-section of a single wall rim, it would look like the letter C.
The spoke bed is the part of the rim where the spokes connect to the reim. The spokes thread onto spoke nipples. Holes are drilled into the spoke bed where the spokes attach. The valve also passes through the spoke bed. Rim tape covers the spoke nipples. The tube rests in the spoke bed. The tire clinches to the sides of the rim.
Single wall rims are usually found on entry-level bikes. They are also pretty common on fat bikes. Most are made from aluminum alloy. Some high-end carbon fiber rims are also single wall.
What are Double Wall Rims?
Double wall rims have a spoke bed that is made of two layers or walls of material. If you were to look at a cross-section of a double wall rim, you would see two thin walls with an empty space in between.
The spoke holes are drilled through both rim walls. The spoke nipples sit in the lower wall, closer to the hub. The tube sits on the upper wall, closer to the tire. The tire clinches to the sides of the rim.
The design of double wall rims can vary. Sometimes the shape is a bit more complex. For example, the chamber between the two layers may be divided up with additional vertical support walls. The distance between the two walls can also vary. Some rims are deeper than others.
Double wall rims are made from aluminum alloy. Carbon fiber models are also available. They are the most common type of rims. Pretty much every mid-range to high-end bike comes with double wall rims. They are available in both tubed and tubeless options.
What is the Difference Between Single Wall Rims and Double Wall Rims?
The difference between single and double wall rims is the design of the spoke bed. The spoke bed of single wall rims is made from one layer of material. The spoke bed of double wall rims is made from two layers of material with an empty cavity in between.
Both types of rims function the same. The spokes attach to the spoke bed with spoke nipples. The valve passes through the spoke bed. The tire clinches to the sides of the rim. Both can be run tubed and tubeless. They are made from the same materials as well. Most are made from aluminum alloy. Some are made from carbon fiber. Single and double wall rims look identical from the outside.
How to Tell if a Rim is Single Wall or Double Wall
The best way to determine whether your bike has single wall or double wall rims is to remove the tire and tube and look through the valve hole. If you only see a single layer of material, the rim is a single wall. If you see two layers of material, the rim is a double wall. There is really no way of telling the difference between the two by visual inspection when the tire is on the rim.
The other option is to look up the rim model online. Usually, rims are marked with a model number and brand name. The rim model may also be listed in the bike’s specifications if your bike has its original rims. If you can find this information, you can easily look them up. The manufacturer’s website will tell you whether the rim is a single wall or double wall model.
Single Wall Vs Double Wall Rims
In this section, I’ll outline the main benefits and drawbacks of single wall and double wall rims. You will find that double wall rims win in almost every category. There are a couple of cases where single wall rims may be the better choice. For this reason, double wall rims are the better choice for most riders.
Double wall rims are significantly stronger than single wall rims. The second wall adds structure to the rim. This greatly improves wheel strength. Double wall rims are less likely to twist, flex, bend, or dent when you hit an obstacle. They don’t warp as easily and they stay true longer. They can take more of a beating without failing. Double wall rims are durable.
Single wall rims are weaker. They can more easily get damaged. Particularly while riding off-road. If you hit an obstacle, you could dent or bend a single wall rim. Single wall rims are so easy to damage that you would be at a disadvantage if you were to race with them. Most competitive cyclists use double wall rims due to the added strength.
The extra strength of double wall rims is really helpful for off-road riding, where obstacles like rocks, roots, and jumps can wreak havoc on your wheels. It’s important to choose rims that can withstand the impact of rough terrain. In this regard, double wall rims have a significant advantage over their single wall counterparts.
For a single wall rim to have the same strength as a double wall rim, it would need to be much thicker. This extra material significantly increases the weight of the rim. More on that in the next section.
Of course, this is all assuming that the rim, hub, materials, component quality, build quality, etc. are the same. The rim design isn’t the only factor that affects wheel strength. The number of spokes is another important consideration. Wheels with more spokes are stronger. The rim size is also important. Smaller diameter rims are stronger than larger diameter rims. Build quality and component quality are important as well. A factory-built wheel with entry-level components won’t be as strong as a professionally built wheel made from high-end components.
It’s also important to note that not all single wall rims are weak. In the past, BMX bikes used single wall rims with 48 spokes. These could really take a beating. Some folding bikes also use single wall rims. For example, before 2013, Brompton folding bike rims were single wall. These single wall rims offer plenty of strength because they are small in diameter. Some premium carbon fiber rims are also single wall and offer plenty of strength.
Winner: Double wall rims are stronger than single wall rims.
Single and double wall rims usually weigh around the same. Sometimes one is slightly lighter than the other.
You would think that double wall rims would weigh more than single wall due to the extra layer of material. This usually isn’t the case.
The reason is that the two walls of a double wall rim are much thinner than the wall of a single wall rim. To make single wall rims strong enough, manufacturers need to make the wall much thicker.
Single and double wall rims weigh around the same because they use the same amount of material to make. The difference is that the material is formed into a different shape.
Single wall rims also tend to be lower-end than double wall rims. They may be made from a lower grade of aluminum that weighs more. This can also add weight.
There are other factors that affect wheel weight. The number of spokes plays a role. On average, spokes weigh 15 grams each. A wheel with 24 spokes is lighter than a wheel with 36 spokes assuming all else is equal. The rim material is also important. Carbon fiber rims are lighter than aluminum rims. Wheel quality is also important. Low-end double wall rims are usually heavier than single wall rims.
Wheel weight is important. The wheels are the best place you can remove weight from your bike. Lighter wheels spin up faster and more easily because they have less rotating mass. It’s easier to accelerate and climb with lighter wheels because you’re moving less mass around. Lighter wheels make your bike faster and more efficient. You can maintain a higher average speed and travel further faster when you use lighter rims.
Winner: Single and double wall rims usually weigh around the same. Sometimes single wall rims are slightly lighter than double wall.
You are more likely to experience a flat tire with single wall rims. This is because the spoke nipples stick up out of the rim bed. If the rim tape wears thin or comes loose, the tube can rub directly against the spoke nipple. Eventually, abrasion between the hard spoke nipple and soft rim can cause a puncture. This is sometimes referred to as an ‘internal puncture.’
The spokes themselves can also cause an internal puncture. If a spoke is too long, it can protrude past the spoke nipple. The sharp spoke can puncture the tube. For this reason, it is crucial that all of your spokes be the correct length if you use single wall rims. No spoke threads should be visible when looking at the spoke bed. If there is a spoke poking up through the spoke bed, you should replace it with a shorter one.
When you use single wall rims, you need to apply rim tape carefully. You need to protect the tube from the spokes. Some riders apply 2-3 layers of rim tape for more protection for the tube.
Punctures can also occur when tightening spokes or truing a wheel. If you overtighten a spoke, the threaded end can protrude past the spoke nipple and into the tube. This can cause a puncture.
This is a common issue when trying to true a single wall wheel. When this happens, it doesn’t matter what kind of rim tape you’re using. You will end up with a puncture. This is easy to do because the spoke nipples sit on top of the rim bed in single wall rims.
You are less likely to suffer flat tires with double wall rims. The reason is that there is more space between the tube and spoke and spoke nipples. On double wall rims, the spoke nipples sit in the lower wall, closer to the hub. The tube rests on the upper wall, closer to the tire.
You have some tolerance thanks to the empty space between the two walls. There are several millimeters of space between both walls. You don’t have to worry if your spokes are a couple of millimeters too long.
When truing your wheel, it doesn’t matter if a couple of threads show past the spoke nipple. You also don’t have to worry about the spoke nipples rubbing on the tube. Rim tape is a bit easier to install on double wall rims as well. You don’t have to be quite as careful.
Winner: Internal flats are less common with double wall rims.
Price of Single Wall Vs Double Wall Rims
Double wall rims are more expensive than single wall rims. The reason is that they are more complicated to engineer and produce. They require more complex molds that cost more to make. More precision is required because the rim walls are thinner. This all adds to the cost.
For this reason, single wall rims are usually found on cheap entry-level bikes. If manufacturers need to meet a price point of $300-$400 or less for a complete bike, they will use single wall rims. Many Walmart bikes and Amazon bikes have single wall rims for this reason. They’re cheap.
Rim prices vary widely. You can buy an entry-level wheelset with single wall rims for as little as $100 or $50 per wheel. These will be factory-made wheels with low-end components.
Decent wheelset with double wall rims start at around $200-$300. A high-end wheelset with double wall rims costs around $600-$1500. You could easily spend $2000+ on a set of premium carbon fiber wheels.
Over the long run, double wall rims are often cheaper than single wall rims because they don’t need to be replaced as often. They also reduce wheel maintenance.
A quality double wall rim might last twice as long as a cheap single wall rim. You may have to buy 2 sets of single wall rims for every 1 set of double wall rims.
Sometimes single wall rims fail prematurely and bend beyond repair if you hit an obstacle. If you hit a pothole hard, a single wall rim could taco. This is less likely with double wall rims.
You may also have to take single wall rim wheels into the bike shop more frequently to have them trued. This also adds to the cost. Double wall rims tend to stay true longer.
Winner: Single wall rims are cheaper than double wall rims. In the long run, double wall rims can be cheaper because they last longer and require less maintenance.
Wheels Staying True
Double wall rims stay true longer than single wall rims. There are a few reasons for this. First, they don’t twist or flex due to the added strength so they stay round longer. If you hit an obstacle hard, there is a good chance that your wheel will stay true.
If a wheel with a double wall rim does go out of true after a hard hit, chances are the bike will still be rideable because the double wall wheels are more durable. They can handle some abuse.
Single wall rims go out of true much more easily. For example, something as simple as hitting a large pothole could cause a single wall wheel to go out of true. After a wheel goes out of true, you’ll have to true it yourself or take it to bike shop to get it trued. Most people don’t have a truing stand to true their own wheels at home. Truing wheels also takes quite a bit of skill. Riding with wheels that are out of true is inefficient. As single wall rims wear, they can start going out of true more easily and more frequently. Having to true your wheels regularly gets annoying.
A particularly hard hit can also bend a single wall rim and render it unrideable. For this reason, single wall rims aren’t the best choice for those who participate in cycling disciplines that are hard on rims, such as many forms of mountain biking.
Because double wall rims stay true longer, they require less maintenance. You don’t need to true them yourself or take them to a bike shop for truing as often. This saves you time and money. Your bike also rolls smoother and more efficiently when the wheels are true. You’ll waste less energy as you ride.
Winner: Double wall rims stay true longer than single wall rims.
Double wall rims last longer than single wall rims. Particularly when they are used in cycling disciplines that are hard on rims such as mountain biking, BMX riding, or bicycle touring.
It’s hard to say exactly how long a set of rims will last. Rim longevity depends on a number of factors including the type of cycling you do, how you care for your rims, the conditions you ride in, how much weight you carry, and more. The type of brakes you use also plays a big role in rim longevity. Friction caused by rim brakes wears rims out over time. Rims last longer when you use disc brakes.
A cyclist who only rides in fair weather and cleans their rims regularly could get 25,000-30,000 miles out of a quality set of double wall rims. A set of single wall rims might last the same cyclist 8,000-15,000 miles. A cyclist who rides during the winter and doesn’t keep their rims clean might only get 2,000-5,000 miles out of a set of rims, regardless of the design.
Double wall rims last longer because they are stronger. They are less likely to get bent during a hard hit. They are also less likely to warp over time.
Of course, any rim can fail prematurely. If you crash your bike or if a wheel takes a hard hit, you can damage a rim beyond repair. If a rim gets bent too much, it can’t be trued.
You can also damage a rim by overloading your bike with too much weight. This can cause rims to crack. Sometimes spokes can pull out of the spoke holes. If you’re planning to tour, you need strong wheels to prevent this.
Manufacturing defects can also cause rims to fail early. Cheap single wall rims are more likely to have defects than decent quality double wall rims.
Winner: Double wall rims last longer than single wall rims.
You’ll have far more rim options to choose from if you go with a double wall model. They are the current standard. Almost every rim worth buying is double wall these days.
Single wall rims are considered obsolete at this point. Only the cheapest of rims are single wall. This limits your options. You won’t find any high-end single wall rims.
The exception is carbon fiber rims. Some premium carbon rims are single wall.
Winner: There are far more double wall rims options available.
Double wall rims are stiffer than single wall rims. The second wall provides extra structure to prevent the wheel from flexing under stress. Stiffer wheels offer several performance benefits.
First, stiffer wheels improve handling. They allow you to steer more precisely and maintain your line better while taking corners. Stiff wheels track well while leaning the bike and cornering hard and while hitting obstacles. The steering feels crisp.
This is because the wheels won’t flex under stress and send you down an unpredictable path. This is important while riding through technical sections of trail or at high speeds. The bike will go where you want it to.
Double wall rims are also more efficient. The stiff rims efficiently transmit power. Less energy is lost to wheel flex. This allows you to ride further and faster while burning less energy.
Single wall rims can flex while taking a corner or hitting an obstacle. This flex is particularly noticeable for heavier riders. If your rims are too flexible, you won’t be able to corner as quickly or predictably.
Wheel flex can also reduce efficiency. Some energy is wasted flexing the wheels rather than driving you forward. You may tire out a bit sooner when you ride single wall rims.
Winner: Double wall rims are stiffer than single wall rims. This improves performance and efficiency.
Lacing a Wheel and Replacing Broken Spokes
It is slightly easier to lace a wheel or replace broken spokes when you use single wall rims. The reason is that the spoke nipples are easier to access. This is because there is no second wall and cavity. When you remove the tire, tube, and rim tape, you’re looking directly at the spoke nipples. They sit right on top of the rim bed. You can easily lace your new spokes. You won’t lose a nipple in the rim.
On double wall rims, the spoke nipples are located between the two walls. They pass through the outer wall and press into the lower wall, closer to the center of the rim. The drawback is that it is possible to lose a spoke nipple inside of a double wall rim. If this happens, it can be a challenge to get it out. This spoke nipple location makes it a bit harder to lace wheels and replace broken spokes.
Of course, if you don’t lace your own wheels or replace broken spokes yourself, this doesn’t really matter. A mechanic at a bike shop can take care of it for you. Most riders don’t maintain their own wheels. Once your wheels are laced and trued, you rarely have to maintain them.
Winner: Single wall hubs make the wheels easier to work on because the spoke nipples are more easily accessible.
When you use double wall rims, you have some leeway in terms of spoke length. The cavity between the two walls gives you a bit of room to work with. If a spoke is a few millimeters too long, you can still use it. A few threads may stick up into the cavity. This is no big deal.
This makes it a bit easier to find a replacement spoke. If a bike shop doesn’t have your exact spoke size in stock, you can use a slightly longer spoke and just let the end protrude into the rim a bit. This isn’t ideal but it is unlikely to cause any problems.
When you use single wall rims, your spokes need to be the correct length. If they aren’t, the spoke will protrude into the rim bed and puncture the tube.
Winner: Double wall rims give you more spoke length options.
Other Considerations When Choosing Rims
The rim wall design isn’t the only choice you’ll have to make when choosing rims. The spoke count, rim construction method, and rim material are all important considerations that can affect the strength, weight durability, and efficiency of your wheels.
Spoke Count: 16, 20, 24, 28, 32, 36, or 48 spokes?
Rims come pre-drilled with spoke holes. The spokes thread into spoke nipples that are placed in the spoke holes.
The hole count is abbreviated with the letter H. H stands for hole. A rim that is labeled 32H will have 32 spoke holes. Hubs are also pre-drilled with spoke holes. Your rim spoke hole count must match your hub spoke hole count.
Different rims come with different numbers of spoke holes. The most common spoke count these days is 32 spokes. Most mountain bikes, commuter bikes, hybrid bikes, and city bikes come with 32 spoke wheels. In the past, 36 spoke wheels were the standard. They are still used on touring bikes. Road bikes and higher-end bikes often come with 24 or 28 spokes these days. You can find wheels with as few as 16 spokes.
The number of spokes affects the wheel’s strength, durability, weight, and aerodynamics. Generally, the more spokes a wheel has, the stronger and more durable it will be. More spokes allow the weight of the bike and rider to be better distributed across the wheel.
The drawback is that wheels with a higher spoke count are heavier. Each additional spoke adds around 15 grams to the wheel’s weight. Wheels with more spokes are also less aerodynamic. The extra spokes create more air resistance and reduce efficiency.
For more in-depth info on spoke count, check out my guide to 32 Vs 36 spoke bike wheels.
Rim Construction: Pinned Rims Vs Welded Rims
When aluminum rims are made, the material is extruded into one long, straight piece of rim. They are then cut to length and rolled into a circle. The ends of the rim are then joined together at the seam. There are two methods used to join the ends together: pinning and welding. The joint type can affect the strength and durability of the rim as well as the cost.
Lower-end rims are usually plugged and pinned. This process involves plugging a pin into both ends of the rim. The ends are then pressed together with a machine. Most single wall rims are pinned.
Higher-end rims are welded together at the seam. This process is pretty self-explanatory. A computerized welding machine welds the ends of the rims together.
Both methods have their benefits and drawbacks. The benefit of pinning is that it’s cheap and simple. This keeps the cost of rims down.
The main drawback is that pinned rims are a bit less durable. They can start to come apart if you ride hard or if the rim suffers a hard hit. This is rare because the spoke tension holds the rim under compression. Most riders have no issues with the durability of pinned rims. Another drawback of pinned rims is that the braking surface can also feel a bit less smooth. Sometimes there is noticeable unevenness at the seam. You may feel the brake pads rub over this spot. This unevenness usually wears down over time.
Welding results in a stronger seam. Welded rims also have a smoother braking surface. Some argue that the heat from welding weakens the rim material at the joint. If they’re welded properly, this shouldn’t be an issue. Welded rims are also more expensive than pinned rims.
Carbon fiber rims are made in a completely different way. They don’t have a seam. Carbon fiber is made by processing a polymer into thin filaments made of carbon atoms. Thousands of these filaments are combined to form a tow or ribbon. These ribbons are woven together into a sheet and impregnated with epoxy resin. The resulting sheets of carbon fiber are trimmed to size with a precision cutting machine.
The pieces are then layered and shaped into bicycle rims using a mold. The carbon fiber sheets and mold are then heated in an oven. This melts and combines the layers into a single piece and hardens the wheels. When the wheels come out of the oven, they are finished. Carbon fiber rims are made from one single piece of carbon fiber.
The vast majority of rims are made from aluminum alloy. Pure aluminum isn’t strong enough for making rims. To increase strength and durability, aluminum is alloyed with other metallic elements such as magnesium, zinc, or silicon.
A number of different alloys are used to make bicycle rims. Different alloys offer slightly different characteristics. Some alloys are stiffer than others. Some are lighter or more resilient than others. The alloy plays a role in the ride quality, weight, and durability of the rim.
The two most common aluminum alloys used for building bike rims include 6061 and 7005. Of the two, 6061 is a bit more common because it weighs less. Both are great rim materials.
Carbon fiber rims are also available. Carbon fiber is a lightweight and rigid material that is made from ultra-strong fibers that are woven into sheets and bound together with epoxy resin. It is essentially a plastic that is reinforced with strong fibers. It is a composite material.
There is a lot of variation in the carbon fiber that is used. For example, manufacturers can vary the type of resin used, the direction of the fibers, the weave of the fibers, the density and types of fibers used, the grade of carbon fiber, the thickness of the layers, the way the material is molded, the heating and cooling process, etc. This all plays a role in the ride quality, strength, durability, and weight of the finished rim.
For more info, check out my guide to carbon vs aluminum rims.
Valve Type: Presta Vs Schrader Valves
The valve type you use can play a role in your wheel’s strength. Two types of valves commonly used on bicycles are Presta valves and Schrader valves.
Rims that are drilled for Presta valves are stronger than rims that are drilled for Schrader valves. This is because Presta valve holes are 2mm smaller in diameter than Schrader valve holes. Schrader valves measure 8mm in diameter and Presta valves measure 6mm in diameter. Less material is removed from the rim when the holes are drilled. The rims remain stronger as a result.
This is really only an important consideration if you’re using skinny road rims. If you’re using wider mountain bike rims, the strength difference is minimal.
There are other benefits and drawbacks of choosing one valve type over the other. For more in-depth info, check out my guide to Presta Vs Schrader valves.
Rims diameter plays a major role in wheel strength and stiffness. Smaller diameter bicycle rims are structurally stronger than larger diameter rims. A 26” wheel is stronger than a 29” wheel.
Smaller wheels are stronger for a couple of reasons. First, the spokes have less distance to span between the hub and rim. With less distance to cover, the spokes can be shorter. Shorter spokes are less likely to bend or break. Larger diameter rims require longer spokes which are more prone to breaking under stress.
Smaller wheels can handle more weight without bending or breaking. This makes smaller wheels a great choice for touring bikes and tandem bikes. If your bike has extra small wheels, you may be able to get away with single wall rims. Some folding bikes have single wall rims.
The hub diameter, width, symmetry, and quality all play a role in the strength and durability of the wheel.
A hub that is larger in diameter helps make the wheel stronger. This is because larger hubs mean you use shorter spokes. Shorter spokes make the wheel stronger because they can’t bend as easily.
Hub width is also important. Wider hubs mean the spoke flanges sit further apart. The flanges are where the spokes attach to the hub. Wider flanges change the angle the spokes run in relation to the hub. This increases wheel strength because the spokes can cross more times when the hub is laced. The more times the spokes cross, the stronger the wheel.
Hub symmetry is also important. Most rear hubs are asymmetrical. The spokes are different lengths and run at different angles on the drive side and the non-drive side. This means spoke tension isn’t even. A symmetrical wheel is much stronger because the spokes run at the same angle on each side and are all under the same tension.
The hubs can also affect your efficiency. Quality hubs have good bearings that roll smoothly. Quality hubs are also sealed better. Hubs that are well-sealed hold up longer by keeping moisture and debris out. This makes the wheel more durable and reliable.
The tires also play a role in your wheel’s resilience and performance. Wide tires offer a good amount of shock and vibration absorption. Wide tires are softer because they can be run at lower air pressures. When you hit a bump, the tire can deform and absorb some of the impact. This greatly reduces stress on your wheels.
Using wide tires also allows you to run wider rims. Wider rims are stronger than narrower rims. They increase wheel strength by reducing wheel flex. The extra material makes for a stiffer wheel as well. With particularly wide rims, you can get away with single wall.
When you run narrow tires, more force is transmitted into the rim when you hit a bump. This is because narrow tires are firmer. You need a strong rim that can hold up to the additional stress if you run narrow tires. Double wall rims are better for narrow tires.
The valve type can also affect wheel strength. The two types of valves commonly used on bicycles include Presta and Schrader valves.
Rims drilled for Presta valves are stronger than rims drilled for Schrader valves. This is because Presta valve holes are 2mm smaller in diameter than Schrader valve holes (Schrader valves measure 8 mm in diameter while Presta valves measure 6 mm in diameter). This means less material is removed from the rim when the holes are drilled. The rims remain stronger as a result.
The valve type really only matters when you’re using skinny road rims. If you’re using wider mountain bike rims, the strength difference is minimal.
For more info, check out my guide to Presta Vs Schrader valves.
How Bike Rims are Made
Rims start out as a block of aluminum alloy. The raw aluminum alloy is melted down and then pressed through a pre-made die. The die is shaped like a cross-section of the rim. The die shape determines whether the rim has a single wall or a double wall. It also determines the thickness of the wall(s).
The material exits the die in a long, straight section of rim. The rims are then cut to length for the appropriate wheel size that is being made (700c, 650B, 26”, 20” etc.). The rim sections are then rolled into perfect circles.
The ends of the rims are then joined together. A couple of different methods are used to achieve this. For higher-end rims, a computerized machine welds the ends together. Mid-range and lower-end rim seams are joined together with a method called plugging and pinning. Pins inserted into both ends of the rim hold the rim together.
To finish the rims, spoke and valve holes are drilled. Braking tracks are machined into the sides of the rims to improve braking performance on rims that are designed for rim brakes. Some rims are also painted or clear-coated for additional protection.
Carbon fiber rims are made in a completely different way. The raw carbon fiber is made by processing a form of graphite polymer into filaments of carbon atoms that measure just 5-10 microns thick. Many of these filaments are bundled together to form a ribbon. These ribbons are woven together to form a sheet. This material is impregnated with epoxy resin.
The sheets are trimmed to size with a machine. They are then layered and shaped into bicycle rims using a mold. Carbon fiber rims come in both single wall and double wall designs, just like aluminum rims. Most carbon fiber rims are double wall. There are some very strong single wall carbon fiber rims on the market as well.
The carbon fiber sheets and mold are then heated in an oven using a special heating and cooling cycle. The heating melts the resin and combines the layers into a single piece of material. The cooling hardens the rims. Spoke and valve holes are then drilled into the rims.
For more info on the different rim materials, check out my guide to carbon fiber vs aluminum bike rims.
Other Types of Rims
In this section, I’ll outline a few other types of rims and their general designs.
Triple Wall Rims
Triple wall rims have a spoke bed that is made of three layers of material. There are two empty cavities between the three layers.
The benefit of this design is that it makes the rims incredibly strong. Triple wall rims are stronger than double wall rims. If you ride in a cycling discipline that is extremely hard on rims, you may consider using triple wall rims.
The main drawback of triple wall rims is the weight. The third wall requires extra material. This adds a considerable amount of weight to the rim. This extra weight reduces efficiency. You can’t spin the heavier rims up as quickly.
Triple wall rims are also expensive. The third wall makes the manufacturing process more complex. There is also less demand for triple wall rims so fewer models are available.
For the majority of riders, triple wall rims are unnecessary. They are an option if you find that you regularly break double wall rims.
Fat Bike Rims
Many fat bikes use single wall rims. There are a couple of reasons for this. First, the fat tires absorb the majority of the impacts to the wheels. The rims and spokes are under very little stress.
The width of fat bike rims also makes them pretty strong. Most fat bike rims measure 50-100mm wide. To compare, most mountain bike rims measure around 25-30mm wide. The extra material adds strength to the wheel without the need for a second rim wall.
Folding Bike Rims
Some folding bikes use single wall rims. Riders can get away with single wall rims because the wheels are smaller in diameter. Most folding bikes use 16” or 20” wheels instead of 700c wheels that are standard on full-sized bikes.
Smaller wheels are structurally stronger than larger wheels. This makes the extra rim wall unnecessary. Many higher-end folding bike wheels are double wall rims anyway.
As a side note, some motorcycles also use single wall rims. Weight isn’t as much of a concern due to the motor. Manufacturers simply make the rims extra thick to add strength. This simplifies manufacturing. The thicker single wall rims are just as strong as double wall, just heavier.
Who Should Use Double Wall Rims?
Most cyclists should use double wall rims. The extra strength greatly improves the durability of the bike. When you use a quality set of double wall rims, you don’t have to worry as much about your wheel bending into a taco when you hit a pothole or ride off a curb. Whether you ride a mountain bike, road bike, city bike, or commuter, you will benefit from double wall rims.
Heavier cyclists will also be better off with double wall rims. If you weigh more than 100kg or 220lbs, the extra wheel strength will be necessary. A single wall rim may not be able to support your weight reliably.
Bicycle tourists and bikepackers should also use double wall rims to support the extra weight of their luggage and gear. In addition, tandem riders should also use double wall rims to support the weight of both riders.
Those who ride in cycling disciplines that are hard on rims should also stick with double wall models. For example, if you are a downhill mountain biker or BMX rider, you will need the extra rim strength so your wheels can hold up to hard hits and landings.
Commuters are also better off with double wall rims. The extra wheel strength improves the reliability of the wheels. You don’t want a wheel to fail you when you’re riding to work or school for an important meeting or exam.
Who Should Use Single Wall Rims?
If you’re a lightweight cyclist and you’re generally easy on your bike, you could get away with single wall rims. For example, a recreational cyclist who just rides bike paths, boardwalks, and around their neighborhood may not need the extra strength that double wall rims offer. For many cyclists, single wall rims are strong and durable enough.
Those who are on a tight budget may also choose to go with single wall rims for the cost savings. If you destroy a rim and all you can afford to replace it with is a single wall model, it’s better than nothing. At least you can still ride your bike. If you’re on a tight budget and all you can afford is an entry-level bike with single wall rims, at least you’ll have something to ride.
Fat bikers can also get away with running single wall rims. The wide tires absorb most impacts so the wheels are under very little stress. The rims are also wider and contain more material, which adds strength without needing a second wall.
Those who ride a folding bike with small wheels can also use single wall rims. Small diameter 16” and 20” wheels are structurally stronger than larger wheels due to their size. They don’t need the extra rim wall.
Final Thoughts About Single Wall Vs Double Wall Rims
For most riders, the choice between single and double wall rims is pretty easy to make. Double wall rims are the clear winner in pretty much every category except for price. Double wall rims are stronger, more durable, and stay true longer. Internal flats caused by the spokes are also less likely thanks to the empty space between the two walls. Double wall rims also have a higher strength-to-weight ratio than single wall rims. Both rim designs weigh about the same.
These days, single wall rims are largely considered to be obsolete. They are reserved for the cheapest of department store bikes. There are some exceptions. Some high-end carbon fiber rims are single wall. Many fat bikes and folding bikes use single wall rims. Some riders have no issues when running single wall rims. Whichever wheels you choose, I hope this guide has helped you in making your decision.
Do you use single wall or double wall rims? Share your experience in the comments below!
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