A Gravaa KAPS (kinetic air pressure system) hubset system has been spotted on Team Jubmo-Visma rider Edoardo Affini's Cervelo S5 at Dwars door Vlaanderen today.
Pictures of the bike shared on Twitter before the race show the Cervelo S5 fitted with Reserve carbon wheel rims, as are usually used by the team, laced onto Gravaa KAPS front and rear hubs. These hubs feature an adjustable tyre pressure system using Bluetooth and ANT+ controls to allow the rider to adjust and control tyre pressures via a handlebar-mounted control unit.
This gives riders the ability to lower pressures for cobbles or rough ground and raise them again on smoother tarmac. Cyclingnews was unable to find prices for the hubset alone, but the GRAVAA R-40|44 road wheelset is priced at €4,299.
Gravaa is based in the Netherlands and its KAPS hubs house a small high-pressure, clutch-controlled pump which is driven by the rotation of the wheel of the bike and controlled by an electronic print circuit board (PCB). Tyre pressure can then be controlled by a handlebar-mounted control or an app. It appears the pump can inflate a tyre directly or from a buffer reservoir built into the hubs within seconds, a valve system also allows for rapid pressure decreases when needed.
Crucially for a professional team, the hubs do not create any extra drag and the pump rotates with the hubs themselves. The system could provide a useful and potentially critical advantage at Paris-Roubaix, in particular, and could combat power losses from rolling resistance on the race's cobbles.
Team DSM previously suggested they would use the Scope Atmoz 'pressure management' system ahead of the 2022 Paris-Roubaix. However, the team opted to use their stock Shimano Dura-Ace wheelsets for the race instead.
The team initially suggested they would defer the trial of the system to the Tour de France in 2022, but again opted against using it in competition. The £3,000 wheelsets haven't seen competitive use from the team but they did recently claim the technology is an 'ongoing project'.
Like the KAPS hubs, the Scope system also claims to add no extra resistance and uses wireless handlebar-mounted controls. So on paper, at least, the systems do seem similar, although the Atmoz uses a reservoir, rather than an inbuilt pump.
Gravaa has published some information on a Paris-Roubaix test it has done and the claimed wattage savings from using lower pressures on cobblestone sections are certainly not to be sniffed at. Testing on the Camphin-en-Pévèle sector of cobbles the race passes over shows a 25-watt saving at 35km/h between tyres when lowering pressure from six bar (87PSI) to three bar (43 PSI). And a 57 Watt saving when riding at 35km/h when decreasing pressure from 4.5 bar (65PSI) to 2.5/3 bar (36/43PSI) from test riders.
In today's peloton, where small single-digit wattage savings are highly valued, the potentially huge wattage savings claimed could represent the difference between winning and losing the race. Teams seem to certainly be aware of the potential savings and advantage, perhaps we can expect to see a tyre inflation system again on the Roubaix cobbles this year if these race testing results are favourable.
The consideration of using the technology in racing has been an ongoing project, with a lot of testing performed over winter. A spokesperson from Jumbo Visma's tyre sponsor, Vittoria, told Cyclingnews that it has been working with Gravaa since 2020.
At this stage, we cannot say for sure whether or not it will be used at Paris Roubaix, but the promise of the system is so great that if Affini reports back positively, it may be too tempting for the likes of Christophe Laporte or Wout Van Aert to ignore.
Cyclingnews has reached out to Gravaa and the Jumbo Visma team to find out.
