This post compares the advantages and disadvantages of aero (bladed) and normal (round) spokes.
The Advantages of Aero Spokes
- More Aerodynamic
The shape of aero (bladed) spokes allows them to “cut through the atmosphere with greater ease than normal (round) spokes. (We find the same principle on Time Trial bikes which have “aero” seat posts rather than standard round ones.)
The effect isn’t pronounced enough to make a huge difference in real life, especially on the recreational scene because the tire and the rim act as a windshield for a large part of the spokes. Thus, the shape of the spokes isn’t as important.
Also, it’s worth mentioning that aero spokes “catch wind” from an angle, and in some cases, they may be creating drag rather than eliminating it.
1 Watt Advantage
A study in a wind tunnel comparing Sapim Laser (round) spokes and Sapim CX-rays (aero) conducted by November Bicycles concluded that aero spokes give а 1 Watt advantage over regular ones.
- An Alternative Look
Some people find aero spokes nicer looking than regular ones and switch simply for the change in appearance. This isn’t surprising because in the world of cycling looks are essential.
- Twisting is Visible and Easier To Prevent
A spoke can twist when one is trying to unscrew a stuck nipple. When the spoke is round, the twisting isn’t as obvious because the spoke looks the same from every angle.
With aero/bladed spokes the situation is different because the flat part makes it easier to see when the spoke is twisting.
The Disadvantages of Aero Spokes
- Instability During Crosswinds
The biggest downside of aero spokes is that they “catch wind” from the side. As a result, the bike can become unstable and thus force the rider to slow down.
This phenomenon is more apparent in the case of disc wheels – a common feature on TT bikes. The purpose of disc wheels is to reduce drag. However, disc wheels are only limited to the back because on the front they make the bike too unstable due to crosswind.
Aero spokes do something similar but to a much smaller degree.
Aero spokes are more difficult to produce. They start as round ones and are later re-forged to their final shape. The forging process gives them extra strength but increases the price too. Some aero spokes cost two or three times more than regular ones.
Plain gauge and single-butted round spokes can be cut to a custom length and re-threaded. This makes them highly customizable and suitable for multiple purposes. In different, aero spokes come at a set length due to the flat mid-body.
A minor disadvantage of aero spokes is that they can cut your fingers when working on a bike if you are not careful. Obviously, this issue is easily avoidable with discipline and proper technique.
- Require Two Tools
Aero wheels require two tools to get them true – a spoke wrench and a spoke holder. The purpose of the spoke holder is to keep the bladed part of the spoke facing forward and prevent winding of the spoke.
The Advantages of Normal (Round Spokes)
- Cheaper and Widely Available
Round spokes, especially straight gauge ones, are cheap and widely available at every bike shop. This makes them the preferred choice of most cyclists.
It’s also worth mentioning that round spokes come in a greater variety of sizes because they’re used on low and high-end bikes. Thus, if you use normal spokes, it’s much easier to find replacement parts.
- Better For Custom Projects
If you need spokes of a custom length unavailable at most bike shops, regular round spokes can be cut and re-threaded unless they’re double or triple-butted.
- Crosswinds Have a Smaller Effect
Round spokes do not “catch” nearly as much wind from the side as bladed spokes. This makes wheels built with regular spokes easier to control during extreme crosswinds.
The Disadvantages of Normal Spokes
- Slightly less Aero
As already mentioned bladed spokes are slightly more aero and give around 1 Watt advantage.
- Non-visual Feed Back
Bladed spokes give the user visual feedback upon winding up. Round spokes look the same from all sides.
|DT Swiss Champion Straight Pull
|DT Competition Race
|Sapim Leader Straight Gauge
|Condor Spokes Straight Gauge
|Wheelsmith Straight Gauge Spokes
|DT Aero Comp
Conclusion: On average, bladed spokes are lighter than straight gauge round spokes but weigh as much or slightly less than double-butted spokes.
Therefore, if you want a lighter wheel, bladed spokes will help you with that goal, but they don’t offer a weight advantage over double or triple butted spokes.
Summary: What You Need To Know
- Aero spokes offer a miniscule 1 Watt aero advantage in comparison to normal, round spokes. It’s questionable to what extent this advantage manifests under rear word conditions.
2. Aero spokes don’t deal well with crosswinds and can make the bike unstable.
3. Aero spokes are more expensive and cannot be cut to a custom length and re-threaded.
4. Some people use aero spokes solely for their appearance.
5. Aero spokes weigh about as much as double-butted round spokes. They’re also lighter than straight gauge spokes.
6. Round spokes deal better with crosswinds and are widely available at bike shops.
7. Round spokes are cheaper and can be cut and re-threaded.
8. Unless you’re a professional rider and care about every single watt, then aero spokes offer no measurable advantage to you other than looks.