Norton Dunstall - Development

Development

Paul Dunstall was a specialist tuner of Norton twins in the 1960s and early 1970s. He started modifying Nortons in 1957, at the age of 18, when he converted a Norton Dominator into a competitive racing motorcycle. As well as fitting a Norton Manx gearbox and wheels, Dunstall balanced the crankshaft and installed the Dominator engine into a Manx Norton frame. With places and two outright wins at Brands Hatch in his first season, after graduating to a higher level with places in his second season at other circuits, Dunstall retired from racing to work in his family's scooter shop and develop performance motorcycle parts

Initially Dunstall conceived simple 'bolt on' modifications such as 'Goldie' pattern straight-through replacement silencers and exhaust pipes, creating his first catalogue in 1961 and gradually growing the business.

Dunstall built engines for other racers and purchased parts left over from Norton's Domiracer project when the factory closed in 1963, using his know-how to further develop high performance motorcycles built to order.

From 1966, Dunstall's customers could choose from a standard catalogue offering a range of speed parts, race-styled accessories and complete ready-modified bikes from Norton, BSA, and Triumph in capacities from 500cc upwards

In 1966 Dunstall Motorcycles became a motorcycle manufacturer in its own right, so that Dunstalls could compete in production races and the Auto-Cycle Union, which is the governing body for motorcycle racing in Britain, approved Dunstall Dominators as a marque for the production race in the 1967 Isle of Man TT.

The 131 mph (211 km/h) 1967 Dunstall Dominator 750 roadster was tested as the fastest motorcycle on the market at the time of its launch.

The early 1960s Norton factory racers were called Domiracer, and although Dunstall called his roadsters both Dominator and Domiracer at various stages and with varying engine capacities, the 750s were not known as Dunstall Atlas. Neither were they known as 'Norton Dunstall' - this is a later corruption as all 1960s literature quotes Dunstall Norton Dominator, or simply Dunstall Dominator.

The last bikes from the featherbed-based machines in the 1969 catalogue were stated as Dunstall Norton Sprint and Export 750 together with the newest bike in the range the isolastic-framed Dunstall Norton Commando.

By the late 1960s, Dunstall had sold to celebrity customers including film star Steve McQueen and Keith Emerson, of progressive rock band Emerson Lake & Palmer.

After the 1968 race season successes, development of the late-1940s designed parallel twin engine was nearing its zenith for the technology of the time with power outputs of 73 horsepower for the race-spec 745cc Atlas-based engine.

For the 1969 season, Dunstall created a new machine with a lower frontal area, the inclined engine being 'underslung' from a large-diameter steel tubing spine frame (nicknamed The Drainpipe) designed by Eddie Robinson. The main frame component ran front to back with a second large-diameter vertical tube at rear of the power plant carrying the engine oil, avoiding the need for the traditional separate oil tank. The filler was conventionally placed ahead of the seat nose

Although Dunstall's open-class racers (non production-race category) were equipped with lowboy frames based on the works design which Dunstall had acquired during the Norton factory race-shop closure, this re-design was based on an established concept not yet applied to the Norton twin for road racing. With no front downtube(s) hence no conventional engine mountings, the spine frame needed substantial cantilever bracing from the central-point of the frame forwards under the gearbox and engine to control the torque reaction

The original 'drainpipe' configuration included aluminium dual 'pannier' fuel tanks inside the top-half fairing sides to lower the centre of gravity and improve handling but following fuel starvation problems a conventional fuel tank was fitted.

In his 2012 article Powered by Dunstall, Nolan Woodbury states there were four Drainpipes made, whereas Drainpipe owner Jamie Waters suggests only three, his own bike having been originally sold by Dunstall to a Swiss Norton dealer and raced in Europe. Jamie also owns a 500cc Domiracer which he built from a NOS (New Old Stock) Dunstall lowboy kit

With discontinuation of the featherbed Atlas in 1968, Dunstall first offered his Commando-based roadsters from the 1969 ctalogue. Sales of the Dunstall Nortons declined in the 1970s and Paul Dunstall concentrated on Japanese marques, in particular forging strong links with Suzuki, eventually selling the name in 1982.