Burt Munro is famous for creating "The World's Fastest Indian" with his 1920 Munro Special. However, he also gained notoriety with "The World's Fastest Velocette" - a 1936 500cc Velocette MSS that he was also working on while competing with the Indian Special. The Munro Velocette (later increased to 670cc) set a record speed of 132.35mph on an officially timed run at Oreti beach in 1971. An unofficial run even reached 138 mph. While some Velocette models could have challenged the record, such as the Works 500cc KTTs Velocette or a fully developed Velocette "Roarer", the factory never put this to the test.

Burt believed that he could have gone even faster with the Velocette at the Bonneville Salt Flats, with a potential speed of 160mph due to the longer run-in to the timed section and the addition of full streamlining. However, there was a trade-off between the power advantage of dense, cold, damp air at sea level and the increased aerodynamic drag. While sea-level runs like Munro's have the benefit of dense air, other venues like Lake Gairdner and Bonneville Salt Flats are hot and dry with higher altitudes, which reduce power output. Supercharged machines have a distinct advantage at altitude because they can increase boost to compensate for the thinner air and benefit from the reduced aerodynamic drag.

The Velocette MSS 500cc model was introduced in 1935 after the success of the 250cc MOV and 350cc MAC. The sophisticated and well-engineered machine, housed in the stronger KSS frame, was popular and continued to be produced until 1948. An updated MSS was introduced in 1954, with a swinging arm frame, a new gearbox, and a new aluminum cylinder head and barrel, which stayed in production until 1969.

Burt owned several MSS Velocettes, competing in reliability trials and races pre and post-war. However, keeping track of these machines is difficult, particularly as New Zealand vehicle registration plates changed regularly up until 1964. Burt was also a traveling salesman for Tappers, the largest motorcycle dealers in Invercargill and Velocette agents. Over the years, Burt acquired several MSS engines, which he tuned and sold to local riders. These "Burt motors" were quick and much sought after despite being fragile.

In 1957, Burt purchased the record-breaking Velocette MSS for £8. The machine was sold by the landlady of a boarding house to settle an unpaid accommodation bill. Burt modified the engine to gradually increase its displacement, and the frame was lowered and modified to accommodate a fully prone riding position. The final version of the machine had a heavily modified aluminum MAC cylinder head. The Velocette also achieved a 12.3sec standing quarter and was no slouch as a sprinter. Burt used to compete in motorcycle drag races at the local Teratonga racing circuit, where one such race nearly killed him. He spent six weeks in the hospital but rebuilt the badly damaged machine within a week of his release.

The Roger Donaldson 1971 documentary about Burt, "Offering to the Gods of Speed," shows him attempting a speed run on the Velocette, which promptly cracks its crankcase below the crankcase mouth. Despite reinforcement, MSS crankcases continued to be a weak spot. Burt claimed that he blew up the engine many times in his search for more power and speed.

Credit: Stuart Francis
Photo: The Hayes Collection

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