Lightweight and Aero and Expensive, Oh My

Bicycles of Tulsa loaned me the wheels to test ride.
Bicycles of Tulsa loaned me the wheels to test ride. Big thanks!

Thanks to Bicycles of Tulsa, I was able to try out two sets of wheels that gave me insight into the overlapping worlds of aerodynamics, weight, and cost (in some cases stupidly-high costs). First, I’ll go into the “why” of a wheel upgrade followed by factors to consider. Then I’ll review the two wheels I tested (use these links to jump straight to the reviews): the Giant P-SLR1 Aero and HED Ardennes SL.

Why upgrade wheels?

Simple: other than the frame, the wheels are the largest component of the bike. Just take a step back and look: they’re big. They almost match the size of your frame. Along with the frame, the wheels account for the majority of the ride characteristics of a bike – and in some ways, even moreso than the frame itself. Consequently, the two most expensive pieces of a bike? The frame and the wheels.

Now, if you like your frame – if it fits, if it works for you – and there’s no particular reason to change it, don’t. If you’re going to replace your frame, you’re essentially buying a new bike. If that’s the case, might as well buy new everything-else with it, and have a second bike.

Wheels can affect a lot of the same riding characteristics as the frame: smoothness, comfort, compliance, control, responsiveness, aerodynamics. But wheels are literally where the rubber meets the road, and so you also have other issues like rolling resistance, steering, acceleration and deceleration. So if you want to change a lot of the capabilities of your bike without changing the frame, the wheels are going to be the area to spend your money.


Like many things on bikes, wheels aren’t just a single component. They’re made up of many pieces that work together as a cohesive unit (or at least, we hope). And sometimes, one bad piece can ruin all the other dynamics of the good pieces of a wheel. The major components of a wheel are the hub, spokes, rim, and tire. I’m not going to consider the tire, because I’ll be keeping my same tire type on whatever wheelset I ultimately decide on.

Rim & tire
Rim & tire

Rims usually account for the majority of the wheel weight. And heavier the rim is, the slower your wheels will accelerate or decelerate. Like an ice skater: arms outstretched and they spin slowly, arms towards the center and they spin rapidly. Because of this, even so-called lightweight wheels can suffer from slow acceleration because though the entire wheel is lighter than other wheels, the majority of the weight of that wheel could be concentrated in the rim. Unfortunately, it’s not common for manufacturers to list the weight of the individual wheel components (such as the rim versus the spokes versus the hubs), which is why it’s important to try them, regardless of what they specs say.

HED Ardennes SL Hub
HED Ardennes SL Hub

Hubs control a lot of the smoothness of the ride, and how long you can coast. The better quality the hub and bearings, the longer the wheel can roll unassisted.

The spokes hold the tension on the wheel, keeping it “true” (i.e. wheel-shaped). Typically, higher-end wheels will have less spokes, but each of those spokes will be made out of stronger material. Sometimes they’re heaver (individually) than wheels more spokes. Spokes also determine a lot of the lateral stiffness of the wheel (how much flex there is from side to side). And newer oval and bladed spokes can change the aerodynamic properties of the wheel.

Then there’s the material: most wheels are made from aluminum, carbon, or a combination of both. You could have an aluminum (or scandium) rim with a carbon fairing (the deep-section that makes the wheel more aerodynamic). Aluminum brake tracks (the portion that your brakes grab on to on the edge of the rim) are standard, and in the past have been shown to have better stopping power in most conditions than carbon brake tracks. Carbon brake tracks also require the use of special brake pads, so as to keep heat down while braking and reduce the chance of warping the rim due to heat build-up.

Aero vs. Lightweight

Lightweight wheels will typically accelerate faster, decelerate faster, and climb better than the stock wheels low and mid-range bikes come with. It might not seem like much, but shaving 4-500 grams (~1 lb) from the wheels can make a massive difference to the feel of the bike. Easier to handle, steering is more confident, etc.

Fluid dynamics: the way air flows around and is perturbed by the passage of an object.
Fluid dynamics: the way air flows around and is perturbed by the passage of an object.

Aerodynamic wheels – wheels that are designed to help cut through the wind – are usually also very light in that most of the additional shape of the wheel is composed of carbon, or the entire wheel rim and even the spokes! But since there’s more of a rim to contend with, you typically get more weight than if you just went with a non-aero, lightweight wheel. Aero wheels have deeper cross-sections or fairings, usually increasing the rim depth to 35mm or more. Aero wheels usually run in the 45-60mm range.

Aero wheels will be of most benefit with a headwind and tailwind, or when riding in a peleton because of the wind stream generated from all of the riders. It reduces the amount of power needed to cut through the wind by forcing the wind to pass more smoothly around the wheels (and even the frame). But this wind-cutting benefit is helpful only to a point. The steeper the wheel angle (yaw) to the wind direction, the less benefit it will be. After about 15°, you usually lose most of the aero benefit of a deep wheel section, and start encountering cross-wind effects.

That deep section that was helping the air move smoothly around the wheel will now start to push on the solid wall of the wheel. In a heavy cross-wind, you can feel the bike being pushed away from your direction of travel, making it harder to keep your line.

Given this, you should find a balance between aerodynamics and weight that suits not only how you intend to ride (touring versus racing) with where you ride. If you ride in an area with a lot of wind (*cough* Tulsa *cough*), cross-winds are a real concern. If you live in a hilly place where you’ll spend more time at slower speeds climbing, weight will probably be paramount.

Giant P-SLR1 Aero
Giant P-SLR1 Aero

Giant P-SLR1 Aero

Suggested Retail:  $1,600


  • Weight: 1,575 g (claimed)
  • Rim Width: 21mm
  • Rim Depth: 50mm
  • Materials: carbon fairing, alloy brake track
  • Spokes: 16 front, 20 rear, bladed, stainless-steel

Tests: 2 rides, totaling 75 miles.

Impressions: First of all, these wheels are definitely lighter than my current wheels. My current wheels are the R-1800 wheels built for Giant by DT Swiss. They weigh in at about 1850 g or so (hence the “1800” in the name, DT Swiss is nice that way). Picking them up at the same time easily shows the weight difference, even though I’d figure that only a third of a pound or so per wheel wouldn’t feel that different. The rear hub is louder than my R-1800 hub, which is odd since both hubs are essentially DT Swiss hubs. That being said, the Aeros spun about as easily as my wheels.

The acceleration on these wheels was noticeable. You feel them jump when you put the hammer down. Braking was also very rapid. Handling felt a bit twitchy, and the ride was also a little more harsh than on the R-1800s, but the Aeros came with 23mm tires and were setup in a tubeless configuration, making them slightly lighter but also slightly rougher handling.

Being in Tulsa, is also becomes quickly apparent that wind and aero wheels don’t mix well. On my first ride, winds were around 9-10 mph, and were pretty consistent. Even at those wind speeds, you could feel the pressure on both the front and back wheels in a cross-wind. Admittedly though, you could also feel the 1-2mph savings when pushing directly into the wind, and even when riding with a tail wind.

The second day though was a real eye-opener. Winds were up to 23 mph, with gusts in the mid-30s. As a tail wind, I felt like I had a sail on my bike. As a headwind, I could feel the aero benefit, works to cut through the wind. But when riding with a 90° cross-wind, I was thrown around like a rag doll. I had to lean into the wind in order to stay on the road or out of traffic.

Overall, I think it’s a great wheelset. Light, quick, responsive. If I were racing, or if I lived in a less-windy area, they’d be mine. Oh yes, they would be mine. But as I’m not racing, and as wind is just a part of riding in Oklahoma, I decided to try non-aero wheels.

HED Ardennes SL
HED Ardennes SL

HED Ardennes SL

Suggested Retail:  $1,100


  • Weight: 1,445 g (claimed)
  • Rim Width: 23mm
  • Rim Depth: 24mm
  • Materials: aluminum alloy
  • Spokes: 18 front, 24 rear, bladed, stainless-steel

Tests: 4 rides, totaling 190 miles.

Impressions: HED is working with the wider-is-better model of rim design that’s become popular among the top names in wheels. The wider rim is said to even out the sidewall of the tire, making for a smoother transition to the rim. This gives you better handling in hard turns, and better contact with the road. The increased width also means you can run lower pressure, which helps prevent pinch flats and adds to ride comfort. It turned out all those claims weren’t just just marketing hype.

When you look at the Ardennes – especially with my 25c Michelin Pro Optimums on there – they look… I don’t know, beefy. Not exactly what you’re going for on a stream-lined machine. But don’t let the look fool you. It might not scream “speed” in the look, but the feel and performance say otherwise. (NOTE: Unlike with the P-SLR1s, I got to use my own tires, which make this a more apples-to-apples comparison to my current R-1800s.)

They’re light – equal to or lighter-feeling than the P-SLR1. Just rolling around the parking lot before my first ride, you could feel the smoothness, the comfort, and the ease of handling even at stall-speeds. Handling was precise and agile, without being twitchy. And cross-winds were no problem – even with a 15 mph wind out of the South while heading West. You don’t get that slippery feeling when working into a headwind like with the P-SLR1, but they climb just as well, and they felt more sure-footed in hard turns.

Two things really stood out about these wheels in comparison to the P-SLR1s and my R-1800s. First, they were absolutely silent! I mean, most free hubs make some kind of clicking noise when you’re not pedaling. My R-1800s are pretty quite compared to most wheels, I’ve found. And the P-SLR1s are on the noisy end, in line with the sounds I hear peoples’ ZIPPs make when they coast past me. But the Ardennes rear hub is only a whisper over the front hub. I know that the sound doesn’t help performance in any way, but it sure makes you realize the time/quality spent hand-building and tuning these wheels. (NOTE: As a buddy pointed out, it could be that the P-SLR1 Aeros were just more used than these Ardennes, and that the hub will get louder over time. But my R-1800s started out far louder than these when they were brand new.)

[UPDATE: I did ultimately by these wheels, and I absolutely love ’em! However, after a particularly wet/rainy/sodden/drenched 50 mile ride, they lost that ultra-silent mystique. 🙁 They’re still rather quite, especially compared to ZIPPs, but just not completely silent.]

Second, and more importantly, the comfort. I was rolling with 95 PSI (usually I ride with 110). HED recommends running at least 11% below recommended tire pressure due to the wider rim configuration (more air volume in the tire). I was worried that I’d feel sluggish, or get a squishy feeling when accelerating. Not so. The wheels were spritely, and the comfort was outstanding. Given that I lean towards longer rides but occasionally like to put the hammer down, this is definitely a huge bonus.

Time To Bust Out The Wallet?

Not quite yet. One good thing to do when borrowing wheels is to get your original wheels back and ride them immediately after returning your borrowed wheels. This will give you a better comparison between what you currently have and what you’re planning on going broke to buy.  If I had to choose between the two sets of wheels, I’d most likely pick the HED over the Giant set at this point. Not because the Giant’s aren’t excellent wheels, but because for my needs, the HED wheels make more sense.