Intelligent interface
Whilst most components and the pneumatic control system, i.e., the intelligence of the wheels, are positioned inside the hub, the lifeline towards the tyre has to run from the hub towards the rim. This also requires attention regarding appearance, aerodynamics, functionality and reliability. The pneumatic interface towards the tyre includes multiple components: a special-designed hydrophobic filter to avoid particles and droplets to enter the system, an overpressure relief valve in the unlikely case of over-inflation, and a standard bicycle pump interface (Presta) to manually inflate the tyres if desired (e.g., at the start of a race).