Carbon or steel? The truth about spokes, and why we build the way we do

Over the past couple of years, spokes have quietly become the most talked-about part of a modern wheel. Rim profiles continue to evolve, but at a reduced pace. Tyre choice has been studied to death. So the marketing attention has moved inward, to the thin lengths of material holding the rim to the hub. And now we’re being told that carbon is the future, lighter and more aero, while steel is the past.

In our view, it’s not quite that simple. Not all carbon spokes are equal, and steel is far from finished. The spoke you should be riding depends on what the wheel is for, and on which trade-offs you are willing to make. Here is how we think about it, and why our GT Series wheels are built with Alpina Carbolite carbon spokes.

Why we build with carbon

We build our premium GT Series wheels around the Alpina Carbolite spoke. We name it deliberately and don’t brand it as a Parcours product. You should know exactly what is holding your wheel together, not just that it is "carbon." Alpina has almost a century of experience in spoke development and manufacturing so we want to be clear that we are using this expertise in our wheels.

The first reason we use a carbon spoke is weight. A carbon spoke is significantly lighter than a steel one, and that saving sits out towards the rim where it matters most. Weight at the edge of the wheel is rotating weight. It is the mass you have to accelerate every time you get out of the saddle, every time the road kicks up, every time you respond to an attack. We know that rotating mass carries twice the impact of static mass when accelerating, so this is why riders will describe a carbon-spoked wheel as feeling “alive” on the road.

The second reason is the Carbolite's profile, and this is where our choice diverges from a lot of the industry. The Carbolite has a razor-thin 3.1mm blade width. That slim profile does three things that deliver the performance we are looking for.

Firstly, the ultra-thin profile, combined with the reduced spoke count actually drives a measurable, albeit small, aerodynamic benefit versus a steel spoke.

It also keeps the wheel stable in crosswinds. A spoke is a small surface, but you have a lot of them, and each one that presents a wider face to a side wind adds to the total cross-sectional area of the wheel. Put simply, a thin spoke gives the wind less to push against. The result is a wheel that stays calm and predictable when the gusts come across an exposed road, rather than one that tugs at the bars and forces you to fight it. For most riders, on most days, that composure is worth more than a fraction of a watt.

Finally, it allows the spoke to work. A thinner spoke has a little more give in it, a touch more stretch and flex under load. That compliance takes the edge off road buzz and lets the wheel track the surface rather than skip across it. It is a similar principle that sits behind our VibraCORE technology: a wheel that transmits less vibration keeps the rider fresher, and a fresher rider is a faster rider. The Carbolite complements our VibraCORE rims, rather than offsetting the reduced transmission of vibrational energy.

Fast, light, stable, compliant. For a performance wheel that is the combination we want and what we design for.

The carbon spokes we choose not to use

There is a second family of carbon spoke on the market, and it is the one you will see marketed hardest. These are wider, bladed carbon spokes, some flat, some with a wavy profile, sold under various brand names and all built around the same pitch: a broad aerofoil section that claims to cut through the air more cleanly than a thinner or shallower spoke.

We tested that argument rather than assuming it and two things stood out.

The aero benefit is small, and it shows up in the wrong place. Independent and manufacturer testing of wide bladed carbon spokes tends to land the gains in fractions of a watt, and those gains cluster at higher yaw angles, when the wind is hitting the wheel from a steep side angle. Our own testing showed the same.

That is not where most riding happens. Our real-world wind data shows that the front wheel (where aero gains are highest and handling stability matter the most) spends almost 90% of ride time below 10 degrees of yaw. In that band, a wider spoke gives you very little back.

The performance trade-off is more significant however. A wider spoke creates more sail area, spread across every spoke in the wheel. That is the crosswind stability problem in reverse. In our testing, the wide-bladed wavy profile spoke we benchmarked against, came out 11% less stable in crosswinds than our Carbolite build. The chart below sets out the figures. You are trading calm, predictable handling for an aero gain that barely registers where you actually ride. For a time triallist holding an aero position on a still day, you can make the argument, but for almost everyone else, it makes less sense.

A wider blade also adds complexity to the build process and in some cases has driven the adoption of a non-captive hub design. To accommodate the ultra-wide spoke, the hub flange either needs a much wider insertion hole (increasing weight or reducing durability) or the spoke slots in from the side. In our view, the latter option presents an unacceptable safety risk, with some high-profile racing incidents showing how such a design can rapidly fail with spokes coming detached from the hub shell.

So we do not build with the wide-bladed carbon spoke. Not because we could not, but because when we weighed the handling cost and build issues against the marginal aero benefits, the return simply was not there.

Why steel still earns its place

None of this makes steel obsolete. In several situations, a quality steel spoke is still the right engineering answer, and we use it where it belongs.

Steel is tougher in the real world. It resists impact and abrasion better, it holds tension reliably over long distances and hard use, and it can be trued and serviced by any competent wheelbuilder with standard tools. If you damage a spoke a long way from home, a steel build is far easier to get running again. For gravel, for heavier riders, for high-load use and for anyone who values roadside serviceability over the last gram, those qualities matter more than the marginal gains of carbon.

Steel is also more forgiving to build and repair, and it costs less. Passing that on where carbon would add cost without adding real benefit is not how we build wheels. A good modern aero steel spoke, such as the Alpina Ultralite that we use, is a genuinely excellent component. It is not a compromise, rather the right tool for a different job.

The point of all this

Whilst on the surface, a spoke choice looks like a spec-sheet line, it is really a system decision. The question is never "is carbon better than steel," because it depends entirely on what you are asking the wheel to do and how you want it to feel underneath you.

For our GT Series wheels, the Alpina Carbolite gives us light, stable, compliant handling that suits the way those wheels are built and ridden. For models where durability, serviceability and affordability lead, steel remains the answer. And the wide-bladed carbon spoke, for all its marketing, does not earn a place in our range, because the handling it costs is worth more than the aero it returns.

The fastest wheel is not the one with the most impressive component list. It is the one that lets you ride at your best for longest. That is the wheel we are trying to build.

Frequently asked questions

Are carbon spokes faster than steel spokes? Not automatically. A light thin-bladed carbon spoke like the Alpina Carbolite reduces rotating weight, which makes a wheel feel quicker to accelerate. But the aerodynamic difference between a thin carbon spoke and a good aero steel spoke is very small. The bigger gains come from weight and compliance, not from air.

Are carbon spokes more aerodynamic? Only the wide bladed-carbon spokes claim a meaningful aero advantage, and both our testing and independent testing shows that advantage is usually a fraction of a watt, concentrated at high yaw angles that riders rarely experience. Almost 90% of riding happens below 10 degrees of yaw at the front wheel, where the benefit is minimal.

Do carbon spokes affect crosswind handling? It depends on the spoke. Thinner carbon spokes, like the Carbolite, present very little surface to the wind and keep the wheel stable. Wide bladed carbon spokes add sail area and can make a wheel more affected by crosswinds (up to 11% less stable in our testing), which is one reason we do not use them.

Are carbon spokes more comfortable? A thinner carbon spoke has slightly more give under load, which helps absorb road buzz and keep the rider fresher over long distances. This works alongside rim and tyre choices rather than replacing them.

Is steel still a good choice for spokes? Yes. Steel spokes are more durable, hold tension reliably, are easier to service and repair, and cost less. For gravel, high-load use and anyone who prioritises serviceability, a quality steel spoke is often the better engineering choice.

Which carbon spoke does Parcours use? We build our premium road and triathlon wheels with the Alpina Carbolite, a light, thin-profile carbon spoke chosen for its combination of low rotating weight, crosswind stability and compliance.