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by Dave Rome
June 3, 2020
Photography by Dave Rome
We’ve seen a number of new road wheelset releases lately. Many are disc-specific and boast ever-wider external and internal rim widths that aim to improve rolling resistance and aerodynamic efficiency, all while making for more predictable handling in gusty conditions.
Most of these wheels are designed around a future with wider tubeless road tyres, which also seek to reduce rolling resistance and the rate of ride-stopping punctures. And while Roval, and its parent company Specialized, was a strong proponent of this new technology, this latest performance wheel line-up flies in the face of it all. Are inner tubes the past, present and future?
Roval’s previous CLX performance road wheel range consisted of three wheel depths, but Roval’s new range offers just two: the aerodynamic Rapide CLX and the lightweight Alpinist CLX. Respectively, Roval says these two new wheelsets are the fastest (and most stable), and lightest wheels they’ve ever produced. Both are purpose-designed disc-brake-only wheelsets, and both are specifically made with tubed clinchers in mind. That’s right, these are not tubeless compatible.
With Specialized conducting ongoing trials of tubeless tyres at the WorldTour level, and presenting plenty of positive publicity for the technology, Roval’s move to tube-only wheels is quite perplexing. And in many ways, the company has backflipped on its recent word.
Now here’s a sticker you wouldn’t expect to find on a 2021 road racing wheel.
According to Roval, the greater (compression) force put on a rim by a tubeless tyre requires extra material, “and that extra mass would have outweighed the benefits of tubeless tires”. As a result, Roval’s decision equates to lighter wheelsets.
However, Roval is clear that tubeless road isn’t going away, but rather hints that the technology may not yet be ready for prime time. “From the Roval side, we recognize the potential of tubeless road tires,” a company representative said. “We evaluate everything in a holistic perspective in the light of what’s best for the rider we’re aiming to serve.
“For now the performance balance tips in favor of tube-type wheel/tire systems for the performance road rider (unless you have a team mechanic to glue on tubulars and a follow car with a spare wheel in case you puncture). We will continue working to realize the benefits of tubeless road systems while reducing the drawbacks.”
Just last year Specialized was making a big push toward tubeless on the road with its new RapidAir technology.
Roval’s move is interesting given where the rest of the market is heading, but is it surprising? Tubeless has dominated the mountain bike space, and has had a similar impact in the new genre of gravel, but it still remains a compromised solution after more than a decade as an option on the road.
Depending on what tests you look at, the very best performing road tubeless tyres can be faster than both the best road-focussed clincher and tubular tyres, but how these minimal measured wattage differences play out in the real world is still widely open to debate. Swap out to thinner clincher tyres with reduced puncture resistance (often designed for time trials), and then the outcome flips in favour of clinchers. With test figures often so close, a simpler clincher tyre with a latex tube within often remains the hot choice amongst rolling resistance weenies, one that also brings with it a far wider choice in rubber.
As seen at last year’s Tour de France, Bora-Hansgrohe outfitted its Specialized S-Works Shiv TT Disc framesets with cotton clinchers and latex inner tubes front and rear. Meanwhile tradition continues on the road, “since they have tech staff and follow cars, tubulars will remain their go-to for the pros for now.”
Add in the ongoing saga of tubeless road standards (or lack thereof), the increased upkeep of liquid sealants, and the associated learning curve, and it’s no wonder that so many road cyclists have stuck with inner tubes. Even wheels from the likes of Enve and now Zipp, that require the use of tubeless tyres, have seen many users run those tubeless tyres with tubes inside – negating many rolling resistance benefits in the process.
That lack of an agreed-upon tubeless road standard has seen some brands take a closed approach to wheel and tyre design (Mavic), while others, such as Enve, have an extensive list of approved and no-no tyres. As it stands, there are some combinations which are potentially unsafe, while others leave a poor user experience with overly tight-fitting tyres or ones that are hard to inflate. Tubeless road can be great (I choose to use it on my own road bike), but unfortunately, such an experience is not a given.
And so perhaps Roval’s backward step shows great market awareness while tubeless technology sorts itself out. Whether this dedication to inner tubes creates a better wheel or not, at least from a marketing perspective I think Roval has quite cleverly gone to safer, calmer waters. In doing so it could, in turn, cater to a larger potential customer base.
And with all that, let’s look at the wheels.
Roval’s latest aero wheel takes front- and rear-specific rim profiles to a new height.
The debate of tubes vs tubeless is far from the only story with Roval’s new wheels. Roval claims that the new Rapide CLX is the best all-road race wheelset in the world, combining the aerodynamic performance of Roval’s CLX64 (64 mm depth) with the handling of the CLX32 (32 mm depth). Some big claims indeed.
Like Hunt’s Limitless Aero 48 and Zipp’s new 303, Roval’s new Rapide CLX aims to keep wind coming off the tyre closely attached to the rim and does so with an extremely broad external width. And where Hunt’s and Zipp’s top-tier disc-specific aero wheels offer widths of 34.3 and 30 mm respectively (and Roval’s previous CLX50 and CLX64 wheels are just shy of 30 mm), Roval raises the stakes with a 35 mm external width on its front wheel.
Roval’s Rapide CLX wheels summarised.
I specify front wheel, as the new Rapide CLX wheelset offers two completely different wheels front to rear. The front rim offers a 51 mm depth that creates a noticeably truncated profile when combined with the enormous 35 mm external width. By contrast, the rear rim features more of a V-shape with a 60 mm depth and 30.7 mm external width. Both rims, front and rear, feature a hooked 21 mm internal rim width.
Roval’s mismatched wheel approach isn’t new — Enve’s SMART wheels started this a number of years ago, and many have followed suit. However Roval’s approach could be one of the most extreme examples seen to date. Roval claim the wheelset “yields less drag than most 65 mm deep wheels, but with 25% less steering torque from wind gusts than the CLX50.” For anyone who’s ever been unnerved by the tug of an aerodynamic wheel in a stiff breeze, these figures are quite intriguing indeed.
The Rapide CLX features totally different rim profiles front to rear. The front rim (pictured left) offers a noticeably wider profile than the already-wide rear rim (right).
At this time it’s unknown just how fast these new wheels are but the company’s press materials certainly make a bigger deal of the real-world testing and speed improvements associated with the wheel’s newfound stability than they do of all-out wind-cheating. Still, Roval’s wheels have a strong reputation for speed; after all, Hunt themselves have said Roval is the benchmark to beat (at least for rim-brake wheels).
Despite the generous depths and widths, Roval’s tube-only decision produces a claimed wheelset weight of just 1,400 g (649 g front, 751 g rear), and my test sample weighed just 20 g more, with rim tape installed. That’s only some 15 grams lighter than the outgoing CLX50 wheels, but with a noticeably wider front rim and deeper rear. And compared to the CLX64, there are 215 g saved.
The wheels are built on the same Aero flange hub design as the previous CLX range; a design that features an oversized flange for the front disc-side and rear driveside. Roval boasts that its hub shell design is aerodynamically optimised, and offers wide bracing angles for a stiffer, stronger wheel. Inside you’ll find an update to the new simpler and lighter DT Swiss EXP hub internals, with the 36T ratchet ring installed.
The new DT Swiss EXP ratchet system uses fewer parts than the original Star Ratchet. It’s arguably one of the simplest and most reliable systems out there.
These hubs feature Centerlock brake mounts and come stock with 12 mm end caps and Shimano HG freehubs. Alternate fitment options are available through DT Swiss’ catalogue.
The Rapide CLXs are built with DT Swiss Aerolite T-Head bladed spokes (a special version of a straight pull spoke), with 18 on the front and 24 at the rear. That front spoke count is quite low for a disc brake wheel, but Roval is using a 2x lacing on the disc side with radial on the opposite side. The rear wheel features 2x lacing on the drive side and 1x on the non-drive side.
And despite the relatively low spoke count, Roval says its new wheels are good for riders up to 240 lbs (109 kg), and that’s with the company’s lifetime warranty period, including a no-fault crash replacement policy that’s valid for the first two years of ownership.
This wheelset is priced at US$2,500 / AU$3,600 (US$1,100 / AU$1,500 front; US$1,400 / AU$2,100 rear). Roval will offer the wheels with a choice of stealth black or white decals.
The Alpinist is for the climbers and weight-watchers. It’s a shallow profile wheel that doesn’t completely ignore aerodynamic gains.
The Alpinist CLX shares much with the Rapide CLX: it’s for disc brakes and tubed clinchers only, and it shares the same hubs, spokes, weight limit, warranty and pricing. But the new Alpinist is shallower, lighter and less wind-obsessed than its aero-minded sibling.
As Roval’s lightest clincher wheelset to date, the Alpinist weighs an actual 1,248 g for the pair (562 g front, 686 g rear), including rim tape. That’s almost exactly 100 g lighter than the CLX 32 Disc it replaces.
Unlike the new Rapide, the Alpinist uses the same-profile 33 mm deep and 26.3 mm wide carbon rim front and rear. While the internal shape features the same hooked 21 mm measurements as the Rapide, that shallower and lighter rim sees the spoke count bumped to 21 spokes on the front and 24 at the rear.
Weight is clearly a key design criteria, but Roval does claim that the new wheels have been aerodynamically designed and tested in Specialized’s Win Tunnel. However, the company hasn’t yet provided any supporting figures for how they compare to the Rapide or other wheels on the market.
For now, Roval has no plans to produce tubular or rim-brake versions of these wheels. Likewise, there’s currently no word on when Roval will produce lower cost “CL” versions of these wheels, although rumours are that they’ll follow in the coming months.
I just received some samples for review and I’m keen to see how they compare to the recently received and almost as wide Hunt Limitless 48 Aero wheels. Will the Rapide’s extreme front wheel width make its sidewalls more delicate to impact? And will such an enormously wide rim suffer fitment issues on some more narrowly spaced disc-brake bikes?
What is blatantly clear from all this is that the industry remains divided on the future of road tubeless.
There’s roughly 150 grams separating the Rapide from the Alpinist. The former will likely prove the faster choice in almost all conditions.
Front- and rear-specific rims aren’t a new idea, but Roval’s approach with differing profiles, widths and depths is quite an extreme take.
Both the Rapide and Alpinist are said to have spent extensive design time in Specialized’s “WinTunnel”.
Roval will offers its new wheels with a choice of either gloss black or white decals. And being decals, you can remove them entirely if you wish.
Actual measured width of the Rapide CLX front wheel.
Actual measured width of the Rapide CLX rear wheel.
Actual measured internal rim width. It was the same across both new wheelsets.
The rear wheels come stock setup for 142×12 mm spacing and with a Shimano 11-speed freehub body. Other axle and freehub fitments can be sourced separately.
The Specialized front hub offers a noticeably larger flange on the disc-side.
Another look at the new DT Swiss EXP. It contains just one loose star ratchet ring and spring, whereas the original Star Ratchet design had two of each.
The Alpinist wheels provide an example of the gloss black decals.
Each wheel comes in a high quality padded wheel bag.