Here are just two . . .
Working in a hut at his home he worked for 20 years to repeatedly modify the 1920 Indian bike and set his first New Zealand record in 1938 and later set seven more. During his ten visits to the salt flats, he set three speed records, one of which still stands. A film was made about his exploits which is well worth watching, and several books have been written about him showing a more realistic perspective.
. . . Rollie was a motorcycle racer best known for breaking the American motorcycle land speed record in 1948 on the Bonneville Salt Flats. The picture of Free, prone and wearing a bathing suit is considered one of the most iconic pictures in motorcycling history.
On September 13, 1948, Free raised the American motorcycle speed record by riding the very first Vincent HRD to a speed of 150.313 mph (241.905 km/h). Special features included the first-ever Vincent use of a rear shock absorber, the first Mk II racing cams, and horizontally mounted racing carburetors. Free had already developed a style of removing the seat from his mount, and lying flat prone along the back spine – thereby minimising wind resistance, and placing most weight over the rear wheel. It is generally believed that this bike is The Black Lightning though, a custom order from the factory and was some 100 pounds lighter and 25 hp more powerful than the stock Black Shadow. In one of his books, Phil Irving (one of the designers) said that there were only about 16 of the model produced. The Black Lightning is the fastest Vincent ever produced.
To protect himself and allow comfort when in such a position, Free had developed special protective clothing. However, when his leathers tore from early runs at 147 mph (237 km/h), he discarded them and made a final attempt without jacket, pants, gloves, boots or helmet. Free lay flat on the motorcycle wearing only a bathing suit, a shower cap, and a pair of borrowed sneakers. This resulted not only in the record, but also one of the most famous photographs in motorcycling history, the "bathing suit bike" shot taken from a speeding car alongside his run on the Bonneville Salt Flats.
For reasons of health and safety, this would not be allowed today ! . . . understandably so.