Mountain bikers who say weight doesn’t matter anymore are kidding themselves. And for the product designers who have bought into the current thinking, it’s just a cop out. Weight does matter, whether we want to admit it or not, and for the decades leading up until just the last few years, shaving grams was a major driver for product innovation across the board.
But we love our dropper posts, and wider, meatier tires, and stuff that doesn’t break as often. All of those things are certainly worth a little added weight because we have to sacrifice something to get them, right?
While tradeoffs are often necessary when it comes to short-term gains, sometimes it’s possible to find a way over, and around an obstacle by rethinking the problem from the ground up. And that’s basically what Roval has done with their latest Control SL mountain bike wheels.
Design and engineering
Green: New rim profile. Gray: Old rim profile. 
Slimmed down rear hub.
Roval, for those who don’t know, is fully a part of Specialized, the bicycle behemoth based in Morgan Hill, California. The wheel brand is spreading its wings a bit of late, developing its own identity apart from the parent, but still fully benefiting from a generous allowance for R&D.
In the case of the Control SL redesign, Roval could afford to really step back and think about what makes a mountain bike wheel fast. The designers and engineers knew that shaving grams could improve riders’ times by precious seconds, but preventing flats could potentially save minutes.
Roval engineer Chuck Teixeira looked at the edges of the rim to understand why pinch flats occur, and after testing 16 different designs, landed on a profile that features a 4mm flat top. The brand claims this design reduces pinch flats by 22%, an impressive amount given such a seemingly minor tweak.
Avoiding a pinch flat in a race could be a time saver in itself, but that’s not the main trick. Because the rims are less likely to cause pinch flats, racers can run the lighter, thinner-sidewall tires that they prefer with reduced risk. Today many of riders are choosing sturdier tires in part to avoid race-killing flats. When looking at the wheel and tire as a system, lightweight, traditionally pinch-flat-vulnerable tires can save riders hundreds of grams of rotational weight, a significant amount for sure.
The Roval Control SL rims feature a shallower cross section than previous designs, and increased overall strength — 29% more impact resistant, according to the brand. A stronger rim gives riders confidence to roll with lower pressures for improved handling. The rims are also significantly wider, at 29mm, than the previous Control SL rims for a better ride feel and improved compatibility with today’s wider tires.
Roval uses 24 straight pull spokes and a single spoke length which makes keeping spares on hand slightly less complicated. Straight pull spokes are lighter than J-bend spokes since they use less material, and the design keeps driveside and non-driveside spoke tensions closely in line with one another. All told the new wheel set weighs 1248g, knocking nearly 100g off the previous version.
Some of that weight saving comes from a redesigned hub shell. Roval uses DT Swiss internals and their own shell design that eliminates unnecessary parts. The rear hub in the Team Edition wheel features 54 teeth for superior engagement, while the “regular” Control SL will feature a slightly less engaged, 36t freehub.
All Control SL wheels come with a 2-year crash replacement warranty and can be configured with a microspline, XD, XDR, or HD driver.
Limited edition
Roval is producing just 650 sets of Roval Control SL wheels, and 600 pairs will be available for purchase. Fifty wheel sets will go to Roval and Specialized teams and athletes, including those competing at the next Olympics.
The Olympics have a number of rules in place to promote an equal playing field, at least when it comes to equipment. Among the requirements is a mandate that gear must be used in competition one year ahead of the games, and it must be commercialized in the same calendar year as the Games. This year, 2020, was set to be an Olympic year and the Roval Control SL release was timed to perfection… until coronavirus hit and decimated the race calendar. Could this give competitors a chance to catch up and produce a rival wheel set for the 2021 games? Given the R&D and manufacturing lead times involved it seems unlikely, but could add another party to the competition beyond the athletes themselves.
Control SL wheels will be available following the Control SL Team edition.
On the trail
Clearly designers put a lot of thought into mountain bike wheels. Riders? Not so much.
Truthfully I was skeptical about testing XC race wheels on shifty desert trails in Baja, Mexico. Running skinny tires on a 25mm-wide rim would be a challenge, and I was hoping to put down the the largest contact patch I could muster on the loose-over-hard terrain. Fortunately for riders, today’s XC is yesterday’s “enduro.” If you don’t believe me, just take a look at this article Matt wrote just 18 months ago discussing rim and tire widths. Back then, a 23-27mm rim was considered trail bike territory. Today, the Control SL wheels go 2mm wider on an XC wheel.
Set up with 2.3-inch Specialized Fast Trak tires, the Roval SL Team wheels made quick work of the trails. I started out running the tires at cross-country pressures for fear or flatting or worse, cracking the high-end carbon rim. But rock hard mountain bike tires are really only appropriate for pavement-like conditions, so I gradually lowered the pressure to get the ride feel and traction I was after. By the end of my testing I was confidently running in the low 20s and was able to fully unlock the potential of the tires. Over 85 miles of riding sand, rocks, and hardpack, I didn’t have a single pinch flat or tire malfunction. In fact, out of the dozen or so riders testing the wheels in Baja, I don’t know of anyone experiencing a single flat.
Lightweight wheels and tires make a huge difference when it comes to climbing and on pedally trail rides. I generally run meaty 2.4- to 2.6-inch tires, sometimes with inserts for extra protection, and over time that weight takes a toll. Jumping on a bike with Control SL Team wheels literally felt like a weight being lifted. Climbs are a breeze and pedaling for hours doesn’t feel like a slog.
All of the trails I rode in Baja were new to me, which meant plenty of panic braking and last second adjustments to make it around tricky corners. The Control SL wheels are nimble and responsive, yet they don’t feel overly harsh.
It’s hard to say what could be improved on the Control SL Team wheels. After all, if there were improvements to be made I’m sure Roval would have made them, costs be damned. Making this level of tech and materials more widely available, and lower price points would certainly be an improvement. On that front it sounds as if Roval will be taking what they’ve learned about the rim profile, for example, and incorporating the design in other wheels within their line. While the limited nature of the initial Control SL Team production and distribution feels a tad elitist, the company does plan to offer the new Control SL design at lower price points.
Who is this for?
The Roval Control SL Team edition wheels are clearly designed and manufactured for world class athletes. That’s a small market for sure — 650 riders, to be exact. But there’s actually something for everyone here, and it’s fairly revolutionary.
Talk to enough folks in the mountain bike industry about product, and you’ll no doubt hear “lighter, stronger, or cheaper: pick two.” For years that’s been taken to be immutable, like the laws of physics. But look closely at the new Roval Control SL wheels and you’ll see that perhaps it’s possible to have all three. By tweaking something as simple as the rim profile, Roval has shown they can make a wheel that’s lighter and stronger, without really adding to the cost. Sure, the wheels are expensive now while the tech is being applied at the Olympic level, but there’s no doubt this innovation will trickle down very soon.
Imagine a day when instead of XC racers looking to trail or enduro tires and wheels for improved durability and performance, trail and enduro riders look at XC wheels for lighter weights with an acceptable level of durability. That day just might already be here.
MSRP: $2,650.
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