Cathy goes undercover in a biker gang in the episode "Build a Better Mousetrap"; donning her usual black leather suit astride a Royal Enfield. Steed, with bowler and 'brolly goes pillion.
A later publicity shot of Honor aboard a Honda (750cc) the very one that usurped the British motorcycle industry in the 70's; though I think it did that itself!
The English rose exudes Italian flair too: here posing with a scooter. Well it has two wheels!