Looking at his Instagram i think also Tom Boonen has switched to some Motorsport competition.
Boonen made his rally debut earlier this year
Cinq ans après avoir fait se grands débuts en sport automobile sur circuit, Tom Boonen va prendre le départ de son tout...
And - little known fact here - Chris Hoy went into motor racing. He even drove at Le Mans. Stephen Roche is another rider turned driver but I can't remember if he ever drove anything anyone remembers.
Roche actually drove some big events....Circuit of Ireland, Ypres Rally, even the Monte Carlo rally.
What's really surprising is he started doing smaller rallies in 1988 while still a pro cyclist...with his directeur sportif Patrick Valcke as co-driver. Can't imagine today's teams would allow that.