Carbon aero wheels: many roadies’ dream upgrade, but can they live up to the hype? We put eleven of the most exciting and trendy models through their paces, in the wind tunnel and on the roads, to find out what really counts when buying aero road wheels.
Deep carbon wheels, with the perfect combination of rims and tires for maximum speed? Hardly any other upgrade is as enticing as a set of high-performance wheels. It’s also by far the most expensive. The decision to invest € 7,000 in the Lightweight Obermayer EVO wheelset isn’t one many of us would take lightly. But even some of the more “affordable” models will set you back by around € 2,000 to € 3,000, with our test field averaging out to € 3,194.
So, which wheelset is the right one for you, and how big are the differences? Is more expensive necessarily better? We tested eleven of the hottest, most unique models for our aero wheel group test, putting them through the wringer on everything from our local post-work laps to high mountain passes. When you’re spending this kind of money on the ultimate upgrade, it’s nice to have some statistics to back up your decision, so alongside our real world riding impressions, you’ll also get some aero performance data for each wheel. We took the wheels to Germany’s most modern wind tunnel, to find out which model is really the fastest.
The aero wheel test field
Our test field includes some of the biggest and most important brands. From carbon pioneers such as Lightweight, to absolute classics such as Mavic and DT Swiss, to established in-house brands from the big players, and newcomers to the world of premium wheels. But this is not just a classic performance comparison. True to the GRAN FONDO ethos, we included some of the most coveted and promising wheelsets, as well as those shrouded in myths. We pitted weight weenie dreams against uncompromising performance monsters, 60 mm aero rims against all-round endurance models, and all-rounders against exotic specialists. As such, our test field is made up of some of the most sought-after and well-known wheels with performance aspirations. However, we still need more specific facts and figures to differentiate the wheels and help you make the right choice.
And which is the most important figure for drop-bar bikes if not the rim depth? This is a group test of wheels in the all-round high-performance segment, which means that they’re aero optimised, but without neglecting the weight. These are wheels that excel both on fast, flat tracks and high mountain passes, not 80 mm carbon bombers or featherweight climbing specialists. As such, we limited ourselves to wheels with rim depths between 45 and 65 mm.
Since the wheels on test should be suitable for modern tires, whether tubeless or not, we also looked for appropriate rim widths. Admittedly, not all models meet this criterion, but the test field just wouldn’t be complete without the legendary Lightweight Obermayer EVO.
Considering the currently raging debate around hookless rims, we obviously had to have both hookless and classically hooked models represented in our test field. And – spoiler alert – some of the hookless models are amongst the best performers. By the way, we recently spoke with some of the leading advocates and critics of hookless rims to take a deep dive on the subject, and better understand both the pros and cons of hookless rims – check out the link here.
Ultimately, we managed to put together an exciting yet also divisive test field. We put the lightest and fastest all-rounders, as well as the hottest models through their paces. The diversity of the test field is also reflected in the prices, though, admittedly, you won’t find any bargains here. However, considering the dizzying € 7,000 price tag of the Lightweight Obermayer EVO, it’s suddenly a lot easier to justify € 2,000 for premium carbon wheels.
| Brand | Model | Price | internal rim width (f/r in mm) | front external rim width (f/r in mm) | rim depth (f/r in mm) | Total weight (g) | |
|---|---|---|---|---|---|---|---|
| Bontrager | Aeolus RSL 51 TLR | € 2,599.98 | 24/24 | 31/31 | 52/52 | 1425 | |
| CADEX | 50 Ultra | € 2,799.80 | 22/22 | 30/30 | 50/50 | 1315 | |
| DT Swiss | ERC 1100 DICUT DB 45 | € 2,500 | 22/22 | 28,5/28,5 | 45/45 | 1465 | |
| HUNT | SUB50 | € 2,789 | 23/23 | 34/30 | 50/50 | 1365 | |
| Lightweight | Obermayer EVO | € 6,990 | 18/18 | 19/19 | 48/48 | 1275 | |
| Mavic | Cosmic SLR 45 Disc | € 2,249 | 19,8/19,8 | 28/28 | 46/46 | 1419 | |
| Reserve | 52|63 | € 2,299 | 26/25 | 35/34 | 52/63 | 1455 | |
| Roval | Rapide CLX II | € 2,700 | 21/21 | 35/30,5 | 51/60 | 1485 | |
| Syncros | Capital SL Aero 60mm | € 4,198 | 23/25 | 31/33 | 60/60 | 1295 | |
| Vision | Metron 60 SL Disc | € 2,209 | 21/21 | 32,5/32,5 | 61/61 | 1614 | |
| Zipp | 454 NSW | € 3,798 | 23,5/23,5 | 27,8/27,8 | 53 – 58/53 – 58 | 1415 |
Wheel group test: Our test methodology
Wheels are more than just one of many components on the bike, like a new handlebar with better aerodynamics or (even) faster ceramic bearings. Wheels influence the bike’s feel and handling like no other component. And that’s why we didn’t just test them in the wind tunnel. We rode the wheels day to day, and in back-to-back tests, fitted tubeless tires until our hands were bloody, and swapped so many cassettes that we could compete with Formula 1 teams in the pit stop.
Real-world tests
To determine the differences in handling and ride feel, we tested in a variety of conditions, went looking for the heaviest crosswinds in southern Sweden, climbed Mont Ventoux in the French Provence, and explored our local routes around the Black Forest. We climbed the steepest inclines we could find, meandered along rolling hills, braved stormy lowland routes, picked our way through potholed asphalt, sailed along freshly paved roads, and bombed down the fastest, most beautiful descents.
We also tested all the wheels back-to-back with the same tires, on the same track, and in comparable weather conditions, within a short period of time. All wheels were fitted with a pair of tubeless 28 mm Continental GP5000 S TR control tires. We selected the tire pressure according to the rider’s weight and the measured tire width in order to mitigate the effect of unknown variables.
We focused on the following criteria for our wheel group test:
Compliance
The wheels’ compliance says a lot about their best use cases. All-rounders and endurance-oriented wheels tend to offer more compliance than thoroughbred racing wheels, making them more comfortable.
Stiffness
Yes, stiffness doesn’t necessarily have a direct correlation with compliance. Above all, a stiff wheel is responsive and agile, steering with speed and precision, and converting pedalling input into propulsion with minimal losses. Stiffness depends on the system as a whole, meaning the hubs, spokes, and rims must work hand in hand, and be designed accordingly.
Handling
The handling results from a combination of compliance and stiffness, though this is also highly dependent on individual preferences. The stiffer the wheel, the more precise, but also the more unforgiving the handling. As a general rule, forgiving handling can instil newcomers with more confidence.
Aerodynamics
While obviously not as precise and objective as the data from wind tunnel tests, aerodynamics can also be observed and assessed in real world conditions, especially when it comes to the sail effect.
Susceptibility to crosswinds
The deeper the rims, the more susceptible they are to crosswinds, right? At least that’s the rule of thumb, but some wheels rely on special features to counteract this. If the wheels are difficult to control, cycling is no fun.
High speed
How quickly do the wheels accelerate, and how easily do they hold the pace?
Climbing ability
All-round wheels should also excel on the climbs, so we tested them all extensively on high mountain passes too. Above all, it’s the weight and acceleration of the wheels that comes into play here.
Wind tunnel
We took the wheels to Germany’s newest cycling-specific wind tunnel. Aerrow from Bad Wörishofen and the specialists from HYCYS have dedicated themselves entirely to the sport, and helped us conduct our tests. As such, we had the privilege of testing the wheels in a modern wind tunnel that was only opened at the beginning of 2024.
We tested all the wheels at a wind speed of 45 km/h, while spinning and mounted to a bike. The bike we used was a Canyon Ultimate CFR, serving as a benchmark for modern road bikes. The wheels were paired with 28 mm Continental GP 5000 S TR tires and tubes, making it easier to swap them around. We inflated them to 5 bar. In total, we determined 21 measurement points at yaw angles ranging from -20° to +20°.
Test results
Admittedly, we didn’t think we would find any particularly big differences between the wheels, but it soon became clear that no two wheels are alike, despite their visual similarities. The wheels all revealed very different characters through the course of our test rides. For example, the ultra light Lightweight Obermayer EVOs stand out as the ultimate climbing companions. Thanks to their extremely stiff and lightweight construction, the wheels are a ton of fun and excel on the high mountain passes. They surpassed all other wheels in this regard. Or the DT Swiss ERC 1100, which proved to be incredibly well balanced wheels, with no surprises or unexpected behaviour – they simply always do exactly what you want and need them to do. Perfect for endurance or leisurely rides, but not for the ultimate performance or thrills on the descents.
Carbon spokes like those on the 50 mm HUNT and CADEX wheels also create a unique riding experience. The high tensile strength of the spokes makes for incredibly stiff wheels. Combined with modern rim geometry and first class aero performance, this results in wheels that are perfect for crit races.
Aero testing
But what about the data from the wind tunnel? This shows how fast the wheels really are, and how much truth there is to the marketing hype. To this end, there are two key figures that we looked at.
First, there’s the CdA value, which indicates the extent of an object’s aerodynamic drag. In our case, this value refers to the bicycle as a whole. Since the drag of the Canyon Ultimate CFR on which the wheels were fitted remains constant, the differences were due to the performance of the wheels. While the values are interesting in themselves, they’re not comparable with other tests.
Secondly, we measured the watts, which cyclists so love. Based on the CdA values, we calculated the power required to move the system at a speed of 45 km/h.
Both values, averaged out over the measured yaw angles, allowed us to compare the wheels. Although this neglects the specific capabilities of individual designs, it gives a good indication of the actual performance – you don’t get to choose which way the wind blows while you ride.
In addition, we also looked at the yaw angles. This describes the angle from which the airflow strikes the object in question – in our case, the bike and its wheels. The relevance of the different angles in real world scenarios depends on many factors, and is hotly debated even amongst the experts. However, it’s clear that the faster you ride, the shallower the angle you’ll encounter. For our test, we measured a range +/- 20°, taking measurements at every 2.5°. This gives us an overview of all relevant angles, as well as the necessary resolution to interpret the values.
On the graph below, you can see the yaw angles on the y-axis and the CdA values on the x-axis. The resulting profile indicates the wheels’ aerodynamic performance across the breadth of the measured angles. In general, the lower the CdA value, the better the aerodynamics, and the fewer watts needed to keep the bike and its wheels going at 45 km/h.
| Brand | Model | Average CdA | Average power in watts |
|---|---|---|---|
| Bontrager | Aeolus RSL 51 TLR | 0.084 | 93.9 |
| CADEX | 50 Ultra | 0.0853 | 95.34 |
| DT Swiss | ERC 1100 DICUT DB 45 | 0.0854 | 95.48 |
| HUNT | SUB50 | 0,0853 | 95.43 |
| Lightweight | Obermayer EVO | 0.0904 | 101.08 |
| Mavic | Cosmic SLR 45 Disc | 0.0871 | 97.4 |
| Reserve | 52|63 | 0.0829 | 92.79 |
| Roval | Rapide CLX II | 0.0833 | 93.17 |
| Syncros | Capital SL Aero 60mm | 0.0822 | 91.89 |
| Vision | Metron 60 SL Disc | 0.0838 | 93 |
| Zipp | 454 NSW | 0.086 | 96.2 |
First of all: all the wheels on test perform well aerodynamically. We tested an entry-level aluminium wheelset in the wind tunnel for comparison, and the performance oriented aero wheels were over 12 watts more efficient on average. Nevertheless, there were clear differences between the performance of the aero wheels. Generally, the wheels can be arranged according to the rim depth.
Wheels with shallower rims, like those from Mavic and Lightweight, tended to perform the worst. That said, the DT Swiss ERCs surprised everyone, delivering a performance on par with the competition from HUNT and CADEX, with 50 mm rims and wide carbon spokes, despite a rim depth of 45 mm. Wheelsets with mixed rim depths performed slightly better, like those from Roval and Reserve, which rely on different rim depths at the front and rear. The idea is to minimise the effect of crosswinds with a shallower rim on the front, and to ensure increased efficiency and a more pronounced sail effect with a deeper rim on the rear. And it seems to work – because despite the shallower front rim, both the Rovals and Reserves outperform the 60 mm deep Vision Metron SLs. Only the Syncros Capital SL Aeros can beat them all, coming in at just under a watt ahead of the pack.
Another surprise is the impressive performance of the Bontrager Aeolus RSL 51 TLRs. Despite the somewhat outdated rim geometry, their aerodynamic performance is significantly better than the competition with the same rim depths. Considering the lack of wide carbon blade spokes, the result is all the more remarkable. Presumably, the Bontrager development team pursued maximum performance at shallow yaw angles by keeping the rims comparatively narrow, resulting in a narrower wheel and tire combination and therefore a smaller frontal surface area. In that scenario, they’re almost on par with the test winners from Syncros.
Aero wheel group test winner: Syncros Capital SL Aero
The test winning Syncros Capital SL Aero wheelset delivers a convincing performance across the board. As the most modern wheels in our test, they feature a one-piece construction, an innovative aero tire pairing (though we didn’t use these), and 60 mm rims, easily checking all the boxes on our wish list. Added to this is the low weight and a perfectly balanced riding experience. Yes, the wheels are designed with racing in mind and want to be ridden at high speeds, but they allow you to do so with ease. Thanks to their first-rate handling, superbly balanced compliance and stiffness, and class-leading aero performance, the Syncros Capital SL Aero wheelset is the deserved winner of our big 2024 aero wheel group test.
Aero wheelset best buy: Reserve 52|63
The Reserve 52|63 wheelset is the undisputed peoples’ champion. With a classic hooked rim design, surprisingly good aero performance, and versatile handling, the wheels deliver an impressively reliable and balanced performance in almost every situation. While they’re slightly heavier than the test field average, weighing in at 1,455 g, they’re still remarkably light for wheels with such deep rims. Considering the excellent and absolutely justified price of just over € 2,000, the Reserves are a no-brainer for performance-hungry and price-conscious riders and racers, making them our well deserved best buy.
Findings
After reviewing all the data and discussing test ride impressions, there are certain findings that stood out. There were a few points and features that surprised us or opened our eyes. Added to that, there are certain things that we won’t want to do without on our next set of wheels. We’ve summarised these findings for you here.
Carbon spokes
Carbon spokes make a stiff wheel, which in turn means responsive and agile handling, but usually at the expense of compliance. They’re a good choice for racing and maximum performance, but somewhat too harsh for leisurely weekend tours. That said, you can always add a little extra cushioning with wider tires, provided your frameset has the necessary clearance.
Continuous rim bed
Can a tubeless setup get any easier? An undrilled, continuous rim bed like you’ll find on the Syncros, Lightweight and Mavic wheels will convert even the biggest tubeless sceptics. Just pop in the valve and the wheel is ready – no tape required and no more slow leaks. More of the same please!
Hoist the sails
Yes, bikes can sail too, and it makes a significant difference. To put it briefly, the deeper the rim profile and the more surface area thanks to wide spokes, the more of an effective sail you’ve got. As such, if the wind is in your favour, you get an added boost (almost) for free.
Tire width matters
The hotly debated topic of tire width also comes into play here, and although skinny tires are faster in the wind tunnel, wider is better, and ultimately faster! Wider tires offer more grip and compliance thanks to lower pressures, which is less taxing on long rides, and is simply more fun. In addition, some wheels are specially designed for wide tires and work best in combination with them.
HOOKLESS
Yes, hookless remains a topic of dispute for the time being. That said, we had no problems during our tests. On the contrary: we had zero issues with the hookless wheels, occasionally outperforming the hooked competition. However, there’s no denying that the limited tire choice and specific pressure requirements make them a little more complicated.
Ceramic bearings
Ceramic bearings promise maximum efficiency and increased durability, though we didn’t notice this during our test. However, at the price points of some of the wheels on test, ceramic bearings are the least we’d expect.
Warranty and crash replacement
Practically all manufacturers offer a warranty extension as well as a crash replacement beyond the EU’s legal requirements. But don’t gloss over the details. Some manufacturers are very conservative in what they offer. Especially when compared to HUNT’s H_CARE program, most can’t keep up.
Human wind tunnel
Our back-to-back tests revealed even small differences in efficiency. We were surprised at how closely the data from the wind tunnel matched our test crew’s perceived findings.
Wheels are expensive
More precisely, good wheels are expensive. The asking price of over € 4,000 for the best wheelset on test is likely to blow most of our budgets. That’s a shame, because unlike some other wheels, they’re price is absolutely justified in this case.
Conclusion
There were big differences between the various wheels on test, but we all agreed: the Syncros Capital SL Aero wheelset is the deserved test winner. That’s not to say the other wheels don’t also have a lot to offer. With so many clever features and innovative solutions, it’s been a while since we had so much fun with a group test. The wheels’ consistently high performance also speaks for itself, which is reassuring considering the prices. If you’re looking for a new wheelset, and you’re flush with cash, you’re certainly spoilt for choice.
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Words: Calvin Zajac Photos: Jan Richter
