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Roval, the components arm of Specialized, has announced the mark II versions of its Rapide and Alpinist carbon wheelsets. The headline feature is that tubeless is back after Roval dropped it, but the more interesting part comes when you get to the impact testing.
With the return of tubeless to its top-end wheels, Roval claims it has “made the fastest wheels on the road even faster” while “bringing the lower rolling resistance, incredible handling, and flat protection of a tubeless system.”
In fact, Roval suggests that the switch back to tubeless results in an average rolling resistance reduction of 8%. To put that into slightly more real-world terms, you’ll supposedly be saving 1.7w per tyre – or 3.5w per bike – when riding at 40kph.
> Roval was pretty sure that clinchers were the fastest in 2019
From what we can see at the rim, not a huge amount has changed, with the super-wide profile of the front wheel remaining. That means you’ll find a 51mm deep front rim that balloons out to 35mm wide externally. The rear remains at 60mm deep with an external width of 30mm. The internal width remains at 21mm front and rear.
What has changed comes inside the rim with Roval embarking on the most “rigorous and extensive engineering and testing program that we’ve ever undertaken” which, the brand claims, “resulted in a wheelset that almost doubles current industry impact standards while managing to achieve the lightest weight possible.”
While we would usually hear these claims being fished out for the release of a hookless wheel, Roval has opted for a hooked rim, pointing to the allowance for higher tyre pressures and greater tyre choice for the end-user as the reasons for the decision.
Interestingly, Roval says that “we’ve also shifted the outer diameter dimensions to create an extra 1.4mm of bead slack in your tire” which they claim will make installing tubeless tyres and then any roadside repairs a fair bit easier.
At the hubs, Roval has moved to ceramic SINC bearings along with a “lighter and simplified ratchet system.” The design apparently “spreads the bearings further apart for added stiffness while making the ratchet more reliable and simplifying freehub body conversion.”
Sagan’s Safety Standards
Interestingly – and possibly because Roval could be overcompensating for the U-turn back to tubeless – the brand has shared a story of the developmental phase of the new wheels. As the story goes, in December 2019 the BORA-Hansgrohe team of Peter Sagan told Roval that “Peter broke a wheel.”
Along followed a picture of a cracked Alpinist CLX wheel with a dismounted tyre. According to Roval, Sagan had tried to hop a roundabout and cased the curb; and while he didn’t expect the wheel to survive the impact, he did expect the tyre to remain on the rim.
Once the development wheel arrived, the Roval engineering team inspected the wheel, finding a small rim bed crack.
Roval said: “These wheels had passed or exceeded all certifying bodies’ standards, including the UCI’s 40 Joule drop test without a tire, but we know tubeless wheels systems have a different failure mode. Cracks in the rim bed could propagate to the rim cavity, and the resulting air pressure creates a failure of the entire system. Repeating the same test with a tube results in lower damage levels. The tube throttles the event over a slightly longer time frame by distributing pressure over cracks and delaying pressure release.”
Roval says that as the “UCI 40 Joule wheel only test was not enough energy to ensure the safe failure mode we believe riders needed” new tests were developed “to determine what kind of damage a rider would expect from an impact.”
This, Roval says, would allow it to build its testing of the entire tubeless wheel and tyre system to exceed that. With this in mind, Roval took its testing outside, rigging up a ‘bump’ which was filled with sensors to repeatedly ride wheels into it.
The result, according to Roval, was “new lab drop testing standards that nearly doubled historical test standards of 40 Joules of energy and required testing of the entire system, not just the wheel.”
Back inside, Roval put the wheel back on its drop test machine and employed two different kinds of strikers, a sharp edge and a blunt radius. The testing covered impacts from 40 up to 70 Joules – the point at which Roval says you’d be unlikely to hang onto the bar. The new standards determined that:
- 40 Joules/Sharp Edge Striker: While the potential for damage exists, you can finish your ride or race without issue
- 50 Joules/Sharp Edge Striker: The wheel may be damaged, but the tire will remain on the rim and the system intact, so you can roll to a stop safely.
- 55 Joules/Blunt Striker: No damage
- 60 Joules/Blunt Striker: While the potential for damage exists, you can finish your ride or race without issue
- 70 Joules/Blunt Striker: The wheel may be damaged, but the tire will remain on the rim and the system intact, so you can roll to a stop safely if you can hang onto the bars
The new wheels
With the new standards in place, Roval says the Rapide II and Alpinist II wheels had to do two things:
- Ensure the entire structure was tough enough to survive a 60 Joule blunt striker impact with no damage
- At 70 Joules with a blunt striker, any cracks in the tire bed or sidewall could not be allowed to propagate, and force would be transferred to the spoke bed
Roval says that it’s fine if the rim is written off at these higher impacts, but the tyre bead must be retained and the wheel’s structure must remain intact to allow you to stop safely.
We got up close to the wheels at Paris-Roubaix and from the looks of that tyre, there will be news from Specialized soon too
Roval claims that “more than 1000 wheels were made and tested during this process, encompassing 150 different layup iterations across Alpinist and Rapide.”
The process supposedly took 21 months, but Roval says that “the resulting rims are the strongest we have ever made,” passing the “rigorous testing standards we have created while delivering more performance as a tubeless system than the world-beating tube-type Rapide and Alpinist.”
Rapide II
Roval claims the Rapide II wheels come in at 1,520g with tape and valves included. You can run 26mm tubeless tyres at 110psi if you wish and there is a 125kg weight limit.
Alpinist II
The Alpinist II, meanwhile, remains at 33mm deep with a 21mm internal width. It gets a slightly different hub shell, but the internals are all the same, as are the weight limit and the max tyre pressure. The claimed weight here is 1265g with tape and tyres.
Both wheelsets will set you back a cool £2,500 and are available now.
specialized.com
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