This photograph deserves some scrutiny, not only for the dashing Kaye Don, but the details in the background as well. Note a 'barrel-back' Morgan 3-wheeler behind Kaye's back, several open touring cars, the white horizontal strip at the far distance which is the Byfleet Banking, ie the banked part of the Brooklands racing circuit (almost vertical at the top, very difficult to climb!). Also, a fantastic sporting combination with an alloy-body sidecar, clearly used for racing with those giant dropped handlebars and a painted number roundel on the nose of the 'chair'. Can't discern the make of the bike, but it looks like a big v-twin, possibly a Zenith.
The date of the photo is April 16, 1921. Kaye Don, later to become famous as a GP star for Bugatti and Sunbeam cars, sits on his pretty little Diamond 250cc ohv machine - a very early example of valves 'up top'. I would assume Mr. Don was a wealthy man, as money was a prerequisite for top-flight auto racing in the 20's and 30's, basically a gentleman's sport, as there were few sponsors and prize money would never finance travel and racing expenses, and certainly not the price of a racing Bugatti! On this day Kaye set a flying kilometer speed record of 69.62mph, which was amazingly fast for such a small machine at this early date.
Notes on his outfit; detachable-collar shirt, necktie with tiebar at the collar, wool sweater, jodhpurs, high wool socks, and street shoes. With exposed everything on his Diamond (chains, valves, etc), no mudguards, and evidence of considerable oil on the engine, its a wonder how his sweater remains clean! Such a dashing portrait, eh?