Maximum speed: New gravel wheels from Specialized

The professionalisation of gravel as a competitive discipline is not only reflected in the fact that there are more and more races and teams are forming, but also in the fact that there are gravel bikes designed for racing and suitable components. Just in time for today's launch of new performance-orientated gravel wheels, test specimens rolled into the editorial office. Well, actually, they were packed in their cardboard boxes, each of which also contains a wheel bag for transport and storage.

Weigh first

No plastic is used in the packaging, even a label attached to the hub is fastened with a paper ribbon. Our first official act was to put each wheel on our laboratory scales. The Roval Terra Aero CLX weighs 1333 grams, the Roval Terra CLX III 1068 grams. For comparison: an average carbon wheelset for gravel use weighs 1500 grams. After the scales, it's time for the practical test. We fitted 45 millimetre tyres to the wheels. Tubeless, of course.

• The Roval Terra CLX III wheelset was fitted with a set of 45 mm Specialised Pathfinder wheels
• The Roval Terra Aero CLX was fitted with a Maxxis Rambler, also in 45 mm width

Fitting the tyres (tubeless) went without a hitch. The bike, which we fitted with the lightweight Terra CLX III, previously rolled on aluminium wheels and was exactly one kilogram lighter as a result. The competition wheels are therefore stylish and light, but we still have to wait for riding impressions and further measurements due to bad weather.

For various racing scenarios

Roval has developed two wheelsets for two different racing scenarios and preferences. The LRS Terra Aero CLX is aimed at riders looking for segment-best times, pro pace and maximum aerodynamics on long, exposed straights. The Terra CLX III wheelset, on the other hand, is designed for climbers, technical downhill riders and those who prefer a combination of low weight and off-road capability. Both build on the carbon construction of the Terra CLX II, but add new rim shapes, composite spokes and reinforced rim hooks.

Why Hooked? Chris Wehan (Roval Category Leader & Product Manager) explains one aspect of why Specialized relies on a hooked construction for the Roval wheels: In the event of a puncture, it is important that the tyre remains in place, as this allows you to continue rolling on the rim in case of doubt. If the tyre slips off and is no longer a protective layer between the ground and the rim, this is not possible. Both wheels should hold tyres securely at a maximum tyre pressure of up to 4.8 bar, but also in the event of a complete loss of pressure.

During development, the development team repeatedly asked themselves whether this would make the rider faster or not. Durability was also essential, because you can't win a race with a broken wheel or a tyre that has slipped off the rim. To summarise: everything revolves around speed and the best performance in the race, which also depends on durability.

Info on the Roval Terra Aero CLX

The development team digitally analysed 300 rim shapes. The aerodynamic resistance, crosswind stability, hook strength, structural stress ratios, weight minimisation and tyre interface performance for 35 to 60 millimetre wide tyres were evaluated. According to Wehan, CT scans of the tyre profiles were created for the simulations in order to examine the complete wheel, tyre and frame system as a whole.

Aerodynamic rim

According to the manufacturer, the final Terra Aero CLX rim shape should deliver the aerodynamic speed of a 70 millimetre deep road wheel while retaining the weight and stability of a flatter gravel wheel.

The rims of the Terra Aero CLX are 38.5 millimetres wide, which is suitable for 35 to 60 millimetre wide tyres. The rim and tyre function similarly to an airfoil: the airflow around the tyre is caught and guided by the larger leading edge radius of the rim. According to the manufacturer, this results in significantly lower air resistance compared to road rim geometries. The Terra Aero CLX uses 5.38 millimetre high rim hooks for maximum puncture protection.

Roval Aero Composite Spokes

The rim is not the only aerodynamic factor. Composite spokes create a cleaner airflow reattachment behind the leading edges of the rim. Their constant stiffness helps to maintain the wheel shape under load and prevents aerodynamic flutter. The Roval Aero Composite Spokes by ARRIS are made of thermoplastic composite material with titanium end pieces, are 20 per cent stronger than steel and save almost 100 grams of weight compared to steel spokes.

Including rim tape and valves, the Aero Gravel wheelset weighs 1340 grams according to the press release, and for the front and rear wheels together, 3500 euros have to be paid over the counter.

Info on the Roval Terra CLX III

According to the manufacturer, the Terra CLX III wheelset weighs 1079 grams including valves and rim tape and is slightly cheaper at around 3200 euros. Compared to its predecessor, the Terra CLX II, comfort and control on rough terrain should be significantly improved. The Roval composite spokes are tuned for ride feel and acceleration. With an outer width of 38 millimetres and an inner width of 27 millimetres, the wheels are optimised for 45 mm wide tyres. The Terra CLX III uses 4.86 millimetre high hooks for the widest tyre compatibility.

Previous tests

The wheels have been tested at BWR California, Big Sugar, Gravel Worlds, UCI Gravel Events, Factory XC Team test protocols and early season pre-season rides. According to Specialized, riders report noticeably higher straight-line speeds on the aero model, reduced fatigue on rough surfaces on the CLX III and superior acceleration and top speed on both models. S. Gomez Villafane from the Specialized Offroad Team said: "Damn, these bikes are fast. Are you sure I can't ride these at Unbound?"

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