Roval CLX carbon clincher review: 32 vs 50 vs 64

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Roval was once a French company that sold innovative wheelsets during the ‘70s and ‘80s. That era came to a close when the brand was acquired and resurrected by Specialized in 2005, however Roval remains steadfastly dedicated to high-performance wheelsets.

There are three premium road wheelsets in Roval’s current catalogue, and in this review, Australian tech editor Matt Wikstrom puts each of them to the test.

Barely two decades have passed since the first high-profile spoke-tensioned wheelsets appeared on the market. Campagnolo’s Shamal and Bora wheelsets are perhaps some of the best-known examples from this early era, where rim profiles where defined by a pronounced V-shape based on NACA airfoil designs.

One of the critical realisations from this period was that rim depth had a far greater impact on aerodynamic drag than spoke count. There was also a growing appreciation for the influence of rim shape, which took a major step forward when Steve Hed and Steve Haug patented the toroidal rim design in 1991.

The potential of that design would not be fully realised until the rise of composites a decade later when it was possible to mould toroidal rims. By that time, factory-built wheels and wheel-systems had started to take hold, paving the way for a stunning growth in general consumer enthusiasm for aerodynamic wheelsets.

The Roval brand pre-dated all of this development by at least a decade, yet many of the French company’s early innovations can be seen in today’s wheelsets. This includes straight-pull spokes, low spoke-counts, hidden nipples, purpose-built hubs, and the integration of the components into a wheel-system. There was even some evidence of mild aerodynamic shaping in Roval’s alloy rims.

In retrospect, it’s clear that Roval was ahead of its time. The brand enjoyed some favour with racers however its wheelsets were far too expensive to attract general consumer interest. As the industry moved on to embrace eight-, nine, and 10-speed transmissions, Roval dwindled away until Specialized bought the company in 2005.

With the support of an industry giant and the benefit of Asian manufacturing, the new Roval easily eclipsed the best efforts of its former self. However, some of the distinction and regard that the French wheelsets once enjoyed was lost along the way, leaving the brand struggling for recognition as a true rival for market leaders such as Zipp and Enve.

On paper at least, Roval’s carbon wheelsets appear sound competition for the market leaders. The company has created three toroidal rim profiles — 32mm, 50mm, and 64mm — that have been diligently refined to minimise aerodynamic drag. There is a clincher and tubular version for each profile to suit rim-brakes plus disc-brake versions for all except the 50mm and 64mm tubulars. That’s makes for a total of 10 wheelsets, all for the one price — AUD$3,600/US$2,400/£1,870 — with the option to buy individual wheels.

Before the ride

CyclingTips has already spent some time looking at Roval’s premium road wheelsets, starting with a press camp earlier this year. Neal Rogers was at the event and provided an overview of Roval’s wheel range along with his initial impressions of the CLX 32 and CLX 50. James Huang followed that up with a long-term look at the disc-brake version of the CLX 32 clinchers. What was missing, though, was a look at the relative performance of each wheelset, which was the main goal for this review.

Roval’s carbon rims are made in Taiwan and feature a rounded toroidal profile that has become de rigueur for aero wheelsets. The CLX 32, 50 and 64 are named for the height (in millimetres) of each rim profile. The external width of each is quite generous, starting at 28.1mm for the CLX 32, increasing to 29.4mm for the CLX 50 and 29.9mm for the CLX 64.

There are tubular and clincher versions for each rim profile, where the latter is tubeless-ready with a bed that measures 20.7mm across the range. Roval supplies plugs for converting the rims for tubeless use, but as James Huang reported, the profile of the rim bed makes it difficult to seat and inflate tubeless tyres, even when tape is used instead of the plugs.

Each wheelset is built with Roval’s AF (Aero Flange) hubset, DT Aerolite straight-pull spokes and Pro Lock external nipples. There are 16 spokes in the front wheel, laced radially, while the rear makes use of 21 (CLX 50, 64) or 24 (CLX 32) spokes and a triplet-lacing pattern (i.e. twice as many spokes are used for the drive-side of the wheel).

Roval’s AF hubs have an elegant shape and sleek styling. DT Swiss supplies the axle assembly for each hub, including its double-ratchet mechanism for the freehub body, while the bearings come courtesy of CeramicSpeed. It’s a high-end combination of parts that suits the wheelset, which seems intent on maximising marginal gains.

Freehub body choice is limited to just Shimano/SRAM, however Campagnolo users will be able to source a suitable body from a Specialized dealer or DT Swiss. Alternatively, for those with 11-speed transmissions, a Shimano-SRAM cassette is a reasonable substitute for Campagnolo’s cogs.

One of Roval’s strongest marketing messages revolves around the low weight of each wheelset, which trump all of Zipp’s products, including its opulent NSW builds, as well as some of Enve’s wheelsets. The weights aren’t so low as to excite weight-weenies, but for a mass-manufactured wheelset, they are impressive, especially for the CLX 50, which hovers around just 1,400g.

The wheelsets sent for review generally lived up to Roval’s published figures with a small excess of 1-4% (22-56g). Thus, the CLX 32 weighed 1,336g (front, 576g; rear 760g); CLX 50, 1,408g (front, 624g; rear, 784g); CLX 64, 1,567g (front, 686g; rear, 881g) (sans rim tape and skewers).

The other strong component to Roval’s marketing claims concerns the aerodynamic performance of the wheels. The company made use of Specialized’s “Win Tunnel” to test prototypes during the development phase and benchmark the performance of the final products. As shown in the figure below, Roval’s wheels match or exceed the performance of Zipp’s Firecrest 202, 454 and 808:

Roval made use of Specialized’s Win Tunnel to measure the aerodynamic drag for each of its CLX wheelsets along with equivalent products from Zipp. All wheels were fitted with the same Turbo Cotton 24C tyre for these tests.

While there is always room to question any in-house data from a wheel manufacturer, it provides some valuable insight on the relative performance of each of Roval’s wheelsets. Thus, compared to a standard low-profile alloy wheelset, the CLX 32 offers ~25% reduction in drag compared to ~50% for the CLX 50 and ~60% for the CLX 64.

The CLX 64 may be the most aerodynamically efficient wheelset in the range, but it comes with a significant weight penalty: 17.3% compared to CLX 32 and 11.1% compared to CLX 50. In contrast, the CLX 50 weighs just 5.4% more than the CLX 32 yet provides a much greater (38%) reduction in drag. Since there is no difference in cost for any of these wheels, the CLX 50 is arguably the most potent of the bunch.

Roval opts for black labels on the unidirectional finish of the rims to keep its branding discreet. There is more branding on the hubs but it too is subdued, so that from a distance, the wheels are largely unidentifiable. That is, until the light catches the gloss of the wheel logos, which makes for a clever effect.

Roval’s CLX 32 clincher weighed in at 1,336g (front, 576g; rear 760g) (sans rim tape and skewers).

As mentioned above, the price for all of Roval’s carbon wheelsets is fixed at AUD$3,600/US$2,400/£1,870. All front wheels sell for AUD$1,575/US$1,025/£770 while the cost for any rear wheel is AUD$2,025/US$1,375/£1,100. Those prices may compare well with other high-end wheels, but in absolute terms, they are still very expensive and well out of reach for most riders.

For those that spend their money on Roval’s carbon clinchers to suit rim brakes, they will get the wheelset, a pair of skewers, two pairs of SwissStop’s Black Prince brake pads, rim tape, tubeless plugs, and a wheel bag. The wheels are also supplied with a three-year warranty however there is a weight limit (109kg/240lbs) and buyers must continue to use Black Prince brake pads throughout that period.

For more information on the features of these wheelsets, visit Roval and Specialized.

The CLX 50 clinchers weighed 1,408g (front, 624g; rear, 784g) (sans rim tape and skewers).

After the ride

Having ridden a variety of carbon wheelsets over the last six years, I had a pretty good idea of what to expect from each of Roval’s carbon clinchers. As the lightest wheelset, the CLX 32 promised to be the most agile and versatile, while I expected a little extra speed as well as some trouble with crosswinds from the CLX 50s and 64s.

Each wheelset was fitted with the same tyres, Specialized Turbo Cotton, that measured 27mm at 50-60psi. I spent the first half of the review period riding the wheels with the tyres inflated to 60psi, and then switched to 50psi for the remainder of my time on each wheelset.

At 60psi, the wheels were obviously stiff, adding an edge to any of the bikes that I fitted them to. There wasn’t a significant difference in stiffness of each wheelset, though. What was more obvious was that the rumble of the wheels deepened as the height of the rims increased.

The CLX 64 clinchers weighed 1,567g (front, 686g; rear, 881g) (sans rim tape and skewers).

Dropping the tyre pressure to 50psi did a lot to soften the ride quality of the wheels, rendering them quieter and gentler. It was a definite sweet spot for me that did a lot to overhaul my impressions, too. Where I was almost convinced they were a race-day product, now I was thinking of them as an everyday wheelset.

By dodging any kind of crosswind, the CLX 32s were the most versatile in the range. They were light and agile, and offered the greatest ease in acceleration. The broad rim bed and generous tyre width made for sturdy and sure-footed wheels that were a joy to ride on any kind of terrain.

The CLX 64s shared the same kind of sure-footedness but they were obviously heavier and slower to accelerate than the CLX32s. Like any other high-profile wheel, they seemed to add some speed to the bike (see below for more discussion) and they were susceptible to crosswinds. On windy days, I needed more effort to control the front wheel and I was reluctant to take my hands off the handlebars. With that said, I wouldn’t classify the CLX 64s as unpredictable or tiresome to use.

The CLX 50s were the most impressive wheelset in Roval’s range. By melding the agility of the CLX 32s with the sense of extra speed from the CLX 64s, I was able to enjoy the best of both worlds. The only compromise was the susceptibility of the CLX 50s to crosswinds, but on balance, they seemed to be more forgiving than the CLX 64s.

During the course of the review period, I kept asking myself if there was actually any difference in the speed or efficiency of the wheels. I’ve often remarked that the aerodynamic performance of mid- and high-profile wheels is something that can be felt in the legs — a gentle easing of pressure but nothing more — but I’ve never had any luck capturing data that proves it.

That’s because there are far too many variables out in the real world that can interfere with power measurements, hence the need for wind tunnels. There are many reasons for this, such as the fact that the rider accounts for the bulk (~70%) of aerodynamic drag, so even small changes in the rider’s position can have an impact on their speed and efficiency.

Specialized Turbo Cotton tyres (24C) measured 27.5mm at 60psi thanks to a generous rim bed width of almost 21mm.

In contrast, the contribution of the wheels is small, perhaps 10-15 % of total drag. Thus, any wheel has to exhibit a profound reduction in drag in order to have a measurable impact on the cyclist’s total effort. Given that Roval’s wind tunnel testing (see above) suggested there was perhaps a two-fold difference in the drag of the CLX 32s versus the CLX 64s, there was a chance that I’d be able measure an impact on my speed.

I opted to perform a relatively simple experiment: on a still day and a quiet stretch of road, I measured my power while trying to hold a speed of ~40km/hr on each of the wheelsets.

My Baum Corretto (a largely traditional road bike with round tubes) served as the test mule for this experiment. I used a set of Verve’s Infocranks to measure my power while my speed and distance travelled was left in the hands of a GPS device. I rode the same ~700m stretch of road at least three times with each wheelset and then compared the average speed and power. The results are shown in the graph below:

Each of Roval’s CLX wheelsets were mounted on the one bike and ridden over the same ~700m stretch of road on a still day. The average speed and power (±SEM) were determined for each effort and plotted as shown. Each point represents a single effort, and at least three efforts were performed with each wheelset.

Admittedly, it was a naïve experiment, but I’m satisfied with the results, because they clearly demonstrate how much variation there can be in the performance of a rider in real-world conditions. The precision of the data is really no better than 20W so I had no hope of measuring a difference of 5%, let alone the smaller changes that might separate the performance of the CLX50s from the CLX 64s or even the CLX 32s.

Of course, there are a variety of ways that this experiment could be improved so that smaller changes in power could be detected, but I think it provides some important context for appreciating Roval’s aerodynamic drag data.

Don’t get me wrong: I have no quarrel Roval’s data. In fact, I’m sure it’s a true measure of the behaviour of the wheels under the conditions they were tested. I’m also sure that any savings in wheel drag translate to the real world, but they are only marginal gains that are easily dwarfed by the other forces acting on a rider.

What that means for any potential buyer trying to weigh up the pros and cons for each of Roval’s carbon wheelsets (or any other brand for that matter) is this: aerodynamic performance is just a nuance that prospective buyers may or may not appreciate when using the wheels.

Another nuance concerns the quality of braking. Carbon rims and rim-brake pads may have improved in recent years, however Roval’s carbon wheelsets did not shine in this regard. Rather, they were only marginally better than a typical carbon wheelset, so the brake pads lacked some bite and more force was required at the lever. But given the expense involved, I’d expect most buyers would be hoping for better.

After all, some of Roval’s competitors — Zipp and Campagnolo immediately come to mind — offer really impressive braking, not just for a carbon rim, but in general terms as well.

Of course, such limitations won’t apply to those contemplating the disc brake version of any of Roval’s CLX wheels, but as the stalemate surrounding the race-legality of disc brakes continues, rim-brake performance is not something that can be ignored yet. With that said, Roval’s wheelsets aren’t dangerous and I don’t expect experienced riders will have much trouble with them.

As mentioned above, Roval claims its CLX clinchers are tubeless-compatible, however James Huang had a lot of difficulty installing tubeless tyres on a set of disc-ready CLX 32s. In my hands, I was able to install a pair of Schwalbe Tubeless One tyres, but I needed an air compressor to do the job. Once inflated and seated, the tyres remained leak-free at 50-60psi, however I share the same concerns as James about the user-friendliness and long-term reliability of Roval’s rim bed design.

The review period was far too brief for me to comment upon the reliability and durability of Roval’s wheels, however they were all still true and round, and the bearings were still spinning smoothly after I was finished with them. Specialized’s Turbo Cotton tyres were a perfect match for the wheels and Roval’s classy all-metal skewers with internal cams were reliable and a pleasure to use.

Final thoughts and summary

Carbon wheelsets were once opulent and exotic products but that has changed in recent years. Now there are many more products to choose from, especially at lower pricepoints, leaving many to wonder what high-end products like Roval’s CLX wheelsets have to offer over the rest of the competition.

The answer relates to the quality of the materials, the durability of the components, and a potential edge in performance. Unfortunately, the law of diminishing returns also applies, so compared to a wheelset that sells for half the price, Roval’s CLX wheelsets may be better, but they aren’t twice as good.

Nevertheless, Roval’s CLX wheelsets offer almost everything that a buyer would want from a high-end wheelset. First, there’s a choice of three wide aerodynamic rim profiles; second, versions to suit clinchers/tubulars and rim-/disc-brakes; third, a robust hub design; fourth, low overall weight; and fifth, sleek and classy presentation.

There are a couple of shortcomings though, namely, the quality of rim-braking and tubeless tyre-compatibility. Both aspects may not be important to all buyers, but given the money involved, and the amount of competition in the current market, Roval’s CLX wheels should be flawless.

What do each of the individual ratings criteria mean? And how did we arrive at the final score? Click here to find out.

Disclosure statement: Specialized is a long-term supporter and advertiser with CyclingTips.

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