Williams' blown wheel hubs believed to be legal

A technical innovation on the new Williams FW35 is believed to be within the rules, despite a similar system on the Red Bull having been declared illegal last season.

The British outfit debuted their new car on track at the Barcelona test last week and those with a keen eye would have noticed they ran the car with hollow wheel nuts.

Further investigation reveals the team have found a way to channel air through the front-brake ducts, into the axle and out through either end. In theory, the clever system blows the wheel hub and improves the flow of air around the tyre and behind within the 'negative zone', decreasing drag and cleaning the flow to the sidepod edge.

Why is this system legal when Red Bull's was banned?

Williams have found a way to stay within the regulations, something Red Bull failed to do. The RB8's interpretation achieved exactly the same, but the airflow exit (the wheel nut) rotated with the axle and protruded past the allowed aerodynamic extremity. It was therefore classed as a moveable aerodynamic device.

Williams have managed to keep their system separate to the axle by passing the air through a static tube within, crucially ensuring it doesn't rotate. They have also designed the wheel nuts in such a way that they are flush with the wheel, thus avoiding the problems encountered by Red Bull which led to them having to change their design at last years Canadian Grand Prix.