This post compares the advantages and disadvantages of single and double-
wall rims.
Definitions
Single-wall rim – single-wall rims have a spoke bed made of one layer (wall). The spoke bed is the place of the rim to which the spokes connect via thread-on nipples.
Double-wall rim – double-wall rims have a spoke bed made of two layers (walls).
The Advantages of Double Wall Rims
- Strength and Light Weight
All things being equal (material, quality…etc.) double-wall rims are stronger than single–wall rims.
The second wall adds a lot of support to the rim to the point where riding off-road with a single-wall rim is considered a big disadvantage due to the increased chances of a damaged wheel.
Simply put, two is better than one.
- Lower Chances of “Internal Flats”
The nipples on single-wall rims are sticking out of the rim bed. This could easily result in a flat tire if the rim tape is worn or out of place.
If the rim has one wall, it’s very important to ensure that the spokes are of the right length for the specific hub and rim and do not protrude past the nipple.
If the spokes are longer than necessary or over-tensioned to compensate for а bent rim, the threaded end of the spokes may protrude and cause an “internal flat”.
Conversely, double-wall rims have a lot more tolerance thanks to the cavity between the two walls.
FAQ: If double-wall rims are stronger, why are fat bike rims single-wall?
Two reasons – 1) the fat tires absorb a lot of stress; 2) the width and thickness of fat bike rims make them pretty strong even with а single-wall architecture.
Some motorcycles use single-wall rims too because weight isn’t a big concern, and thus the rim can be as thick as needed.
The Disadvantages of Double Wall Rims
- Price
The main disadvantage of double-wall rims in regards to single-wall rims is the extra cost. Double-wall rims are more expensive due to the more complicated building process.
Hence why single-wall rims are commonly found on cheaper bicycles where the manufacturer is trying to minimize all expenses.
- More Difficult Access To The Nipples
The nipples on double-wall rims are located in the cavity between the two walls. Thus, it’s a bit more difficult to access them.
On occasion, one can also lose a nipple inside a double-wall rim. Getting it out is not a fun process.
Meanwhile, the ends of the nipples on single-wall rims sit on top of the rim bed and are fairly accessible. (Also, it’s not possible to lose a nipple in a single-wall rim.)
Thus, one can argue that it’s easier and faster to lace a single-wall rim, especially when you have the right tools (e.g., a nipple driver)
The Advantages of Single Wall Rims
- Cheaper
The most attractive property of single-wall rims is their low price. If you’re on a budget or want to build a beater bike, single-wall rims fit the bill thanks to the lower price tag.
- Easier Access To The Nipples
As already mentioned, the lack of a cavity makes it easier to see and access the nipples on a single-wall rim.
The Disadvantages of Single Wall Rims
- Strength Equals Extra Weight
A single-wall rim is not weak by default. In fact, there are some old-school single-wall BMX rims with 48 spokes that can take more punishment that one can imagine. However, that strength comes at a cost – more material and thus more weight.
In order for a single-wall rim to match the strength offered by a double-wall rim, it needs to be thicker. The extra material increases the weight of the rim and wheel substantially.
If two rims are of the same quality, weight and material, the double-wall rim will be stronger.
- Easier To Get Internal Flats
Ideally, no spoke threads will be visible. Hence why it’s very important to get spokes of the correct length when lacing a wheel.
In practice, however, this isn’t always the case. It’s common for people to get a small dent in the rim and overtighten a spoke pulling in the other direction to compensate for it. When that happens, the spoke protrudes past the nipple. As a result, it becomes very easy for the spoke to pierce the inner tube almost regardless of what rim tape one is using.
Single-wall rims facilitate this process because the nipples are on top of the spoke bed.
- Get Out of True More Easily
A single-wall rim is more likely to get out of true than a double-wall rim (if the quality of both rims is the same).
- Fewer choices
To a large extent, single-wall rims are currently obsolete. This limits the available options, especially if one is looking for a high quality rim.
- A Shorter Lifespan
If the rim is going to be used for extreme riding (MTB, BMX…etc.), then a single-wall rim is very likely to have a much shorter lifespan. Thus, the money that one saves becomes questionable given that the rim is not likely to survive as long as a double-wall one.
FAQ: How to tell if I have a single or double-wall rim?
Method 1: Look up the rim model online.
Method 2: Remove the tire, the rim tape and look for a dual-layer section at the valve hole. If it’s absent, you have a single-wall rim.
FAQ: What about triple wall rims?
Triple wall rims have three layers and thus two cavities instead of one. They’re notably stronger than two wall rims but also heavier. Since two wall rims can handle a lot of stress, triple-wall rims are not very popular, especially among recreational riders.
Summary: What You Need To Know
- Single-wall rims have a spoke bed made of one layer whereas double-wall rims have a spoke bed made of two layers.
- Single-wall rims have an inherently weaker infrastructure than double-wall rims unless the manufacturer makes the rim extra thick. At that point, however, there’s a notable weight penalty.
- Single-wall rims are more likely to cause a flat tire due to a nipple or a spoke end piercing the inner tube. Conversely, double-wall rims “hide” the nipples in the cavity between the two walls. This provides some room for “error”.
- All things being equal, double-wall rims are stronger and require less frequent truing.
- Due to the practicality and strength-to-weight ratio of double-wall rims, single-wall rims are close to obsolete. One finds them primarily on cheaper bicycles located at department stores.
- If you want to invest in the future, a quality double-wall rim is the logical choice. That said, single-wall is still better than a zero wall (not having a rim). If you have a single-wall wheel but no money to upgrade, ride and have fun. Because that’s all that matters in the end, isn’t it?
