1951 Vincent Black Lightning

998 cc (60.9 cu in),70 bhp (52 kW) and a top speed of 150 mph (240 km/h).
Only 31 Black Lightnings were ever built before production ended in 1952.

On 13 September 1948, Rollie Free achieved the US national motorcycle speed record at Bonneville Salt Flats in Utah riding the first Vincent Black Lightning. During test runs Free reached average speeds of 148.6 mph (239.1 km/h).
To reduce drag, Free stripped to his swimming shorts for the final run, which he made lying flat with his legs stretched out and his head low, guiding the Vincent by following a black stripe painted on the salt bed.
The stunt worked as Free covered the mile in 23.9 seconds, passing the 150 mph (240 km/h) barrier and on the return run he reached a record average speed of 150.313 mph (241.905 km/h).
This led to one of the most famous photographs in motorcycle history, known as the "bathing suit bike".

Source: Wikipedia