As gravel cycling as a discipline has begun to define itself, so has the equipment needed to compete at the highest level. While there are two distinct offshoots forming – race and adventure, it’s the former developing apace, particularly when it comes to aerodynamic efficiency. We’ve seen this maximised over the past few years, with everything from framesets to clothing adopting gravel-specific aerodynamic enhancements, but it’s in the best gravel bike wheels department where big gains are being unlocked.
Wheel manufacturers such as Zipp, with its 303 XPLR SW and locally, the Parcours FKT and Strada Gravel Aero Plus, all offer aero gravel wheelsets, and now Specialized’s component arm, Roval, is pushing the envelope even further focussing on aerodynamics and weight reduction with the introduction of two new gravel wheelsets, the Terra CLX III and Terra Aero CLX.
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Matt Beers used the Roval Terra Aero CLX to win the 2025 Big Sugar Gravel elite race
(Image credit: Specialized)
Roval Terra Aero CLX wheelset
The goal for Roval was to create the fastest gravel wheelset, which led to over 300 digital rim-shape studies focused on areas such as aerodynamic drag, crosswind stability, structural stress ratios, weight reduction, tyre interface performance (35-60mm), and hook strength. Like the original Terra and Terra II models, the Roval Terra Aero CLX wheels eschew hookless rim architecture in favour of hooked beads for more secure tyre retention. To bolster this and ensure the tyres don’t pinch flat when using lower pressure and hitting a rut, Roval has bolstered the hooked bead profile to 5.38mm.
Unlike some wheel manufacturers, Roval’s CFD studies included the entire wheel system – tyre included- and matched it to a frameset, as shapes that look fast in isolation often produce turbulence at the tyre-rim junction, nullifying any gains. Roval’s tests included carrying out various tests, including monitoring the airflow around 45mm Tracer gravel tyres on a Specialized Crux and other metrics such as bike-fork spacing and wheel offset, expected on-course yaw distribution and yaw fluctuations specific to gravel racing.
This all led to a specific rim shape with a heavily cambered leading edge. As a result, the Terra Aero CLX wheel system delivers the same speed and performance as a 70mm-deep wheel. The result is 50/40mm front/rear ‘Chopped Aero’ shaping that reduces airflow separation behind the tread and keeps it flow attached longer at yaw – aero gains are especially strong from 5- to 12-degrees yaw, a bandwidth where gravel racers spend most of their time.
Roval has bolstered the hooked bead profile to 5.38mm for more secure tyre retention and to avoid pinchflats when running lower tyre pressure
(Image credit: Specialized)
According to Roval, the Terra Aero CLX wheels were optimised around Specialized Tracer 45 gravel bike tyres and tested 5.84 watts faster than the outgoing Terra CLX II in the wind tunnel. While the wheels are designed to work best with tyres ranging from 35-45mm wide, they can accommodate tyres up to 60mm wide. The CFD studies also examined spoke airflow interactions to assess any aerodynamic advantages of including Arris carbon spokes. The results showed that thinner composite spokes consistently outperformed rounded profiles by 0.5-0.3 watts across realistic yaw angles, prevented aero flutter and provided a better integrated aero system.
In terms of specifications, the Terra Aero CLX are right on the money, weighing 1,340g (640g front, 700g rear) a pair and boasting a 38.5mm external and 27mm internal rim width. The wheels are laced in an 18/24 front/rear spoke configuration and come standard with Sinc ceramic bearings and a Ratchet EXP freehub system with 36 points of engagement.
The wheelset will retail for £2,988 (£1,299 front, £1,699 rear) in the UK and $3,400 ($1,500 front, $1,900) in the US.
The Arris flat-top carbon spokes save 0.5-0.3 watt over the rounded version and were 20% stronger and 96.6g lighter than the steel equivalent
(Image credit: Specialized)
Roval Terra CLX III wheelset
Roval has also introduced the lightest gravel race wheels it has ever made, weighing 1,079g for the pair (489g front, 590g rear). The wheels have been developed around a fairly shallow 27mm rim depth, but retain the same 4.86mm hooked bead profile and similar 38mm external and 27mm internal rim widths. To achieve this particular rim shape and depth, over 200 iterative rim shapes were generated using multi-factor modelling and evaluated for weight, lateral stiffness, and hook stress. Like the Terra Aero CLX, during testing, it was found that Arris-developed, wider flat-top carbon spoke delivered a 0.5-0.3 watt savings over the rounded version and were 20% stronger and 96.6g lighter than the steel equivalent.
The Terra CLX III applied lessons learned from high-pressure impact standards on the Roval Control WC MTB and Rapide CLX III wheelsets. This, paired with a tuned carbon-fibre layup, has resulted in a 21.52% reduction in lateral stiffness, providing smoother control and compliance, often compromised by vibration-induced power loss on washboard gravel.
While the Terra CLX III shares much of its hardware and specs with the Terra Aero CLX, such as the DT Swiss 180 hubs with 36T Ratchet EXP internals and Sinc ceramic bearings, the 21/24 front-to-rear spoke configuration differs. Roval quotes a system weight limit of 125g.
They will retail for £2,748 (£1,149 front, £1,599 rear) in the UK and $3,200 ($1,400 front, $1,800) in the US.
We’ve been sent a pair of Roval Terra Aero CLX for testing and will be publishing our comprehensive review in the coming months, so keep an eye out on the Cycling Weekly homepage.
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