Gravaa, the Dutch company behind the KAPS adjustable tyre pressure system, has been declared bankrupt in the Netherlands, according to court records published this week, with a liquidator now appointed to manage the insolvency.
The filing seems to spell the end for the hub-based on-the-go tyre inflation and deflation system, which had already found its way into WorldTour at Paris-Roubaix and the gravel world championships on Marianne Vos’s Cervelo Aspero 5 despite only reaching limited commercial production.
The KAPS tyre pressure management system allowed riders to inflate or deflate their tyres while riding, and first appeared at Eurobike 2021. The system integrated a miniature reciprocal membrane pump directly into a proprietary hub, with the pump driven by a camshaft powered by the rotation of the wheel itself. A pneumatic clutch automatically engaged or disengaged the pump at the click of a button on the rider’s handlebars.
The system paired wirelessly with a rider’s head unit to display live tyre pressure, used bar-mounted satellite shifters as inflation and deflation controls, and inflated or deflated both wheels simultaneously. Inflation rates were claimed at up to 1.5 bar per kilometre, with deflation happening much quicker.
This design had its pros and cons. Gravaa claimed the system introduced no additional drag when inactive or during deflation, with an estimated four-watt drag penalty per wheel only when the pump was actively inflating. It also added around 250 grams per wheel, and the system required fully proprietary hubs, valve hardware, brake rotors, and, obviously… wheel builds. Unlike hub-mounted add-ons such as Scope’s Atmoz system, KAPS had to be built into a complete wheelset, limiting flexibility and increasing complexity. Remember Powertap? Furthermore, the system wasn’t yet compatible with tubeless sealant, and rumours within the industry suggest that the tolerances were so tight that it proved temperamental in use.
At the pro level, however, the system did gain some traction. First, with UCI approval for use in competition, which paved the way for Visma - Lease-a-Bike to use the hubs in the spring classics over several seasons, where on-the-fly pressure adjustment could offer a tangible advantage on mixed cobble and smooth surfaces.
Despite early impressions that the system was close to production readiness as far back as Eurobike 2021, Gravaa continued to refine both hardware integration and software. By 2023, Gravaa had added safety features such as an automatic shut-off in case inflation was accidentally triggered during transport, and a fail-safe mode that reverted the remaining wheel to a preset pressure in the event of a puncture-induced wheel change.
In an email shared with industry partners, teams, and friends ahead of the bankruptcy filing and seen by Escape Collective, Gravaa's commercial director, John Zopfi, outlined the reasons behind the company’s collapse.
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