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1969 750cc Dunstall Norton - The 144mph Drainpipe

1969 750cc  Dunstall Norton - The  144mph Drainpipe

Paul Dunstall was Britain's leading tunder of Norton twins in the Sixties and early Seventies. The enterprising South-East Londoner bought left-over parts from Norton's Domiracer project when the Birmingham factory closed in 1963, and used them as the basis for onward development. Bright red Dunstall Domiracers were highly effective on the track and the 130mph Dunstall Atlas roadster was the fastest motorcycle on the market.

In 1967 750cc Dunstall rider Rex Butcher collected a bunch of world records at Monza in Italy, including one hour at 126.7mph. In 1968, Dunstall rider RayPickrell won many short curcuit races on a Domiracer, as well as winning the Isle of Mann 750cc Production TT on a Dunstall Atlas.

The ultimate Dunstall Norton racer was built for 1969, featuring a new frame to cope with the 70-plus horsepower that the team was wringing from Norton's 750cc Atlas engine. Designed by Eddie Robinson, who also worked for the Seeley equipe, the open-bottomed oil-carrying structure has a spine of large-diameter tubes that earned it the drainpipe nickname.

Experimental pannier fuel tanks inside the fairiing on this machine are intended to lower its centre of gravity and improve handling. However, no fuel pump was fitted and starvation problems saw the Dunstall team revert to a normal tank for most events.

During 1969, Pickrell rode Dunstall machines to gain two speed records. One, thought to have been set on this machine, was a new national record for the 750cc flying-start quarter mile at 144.69mph established at Elvington, Yorkshire. The other, set on another Dunstall team visit to Monza, was a world 750cc record for 10 Kilometres covered at 131.51mph, which stood for seven years.

  • Engine - 745cc (73 x 89mm) are-cooled overhead valve parallel twin, 10.25:1 compression ratio, two 32mm Amal carburettors, Lucas magneto ignition
  • Transmission - Chain primary drive, dry multiplate clutch, five-speed gearbox, chain final drive
  • Chassis - Tubular spine frame, telescopic fork front suspension, swinging arm rear suspension, drum brakes
  • Wheels - 18in
  • Power - 72bhp @ 7000rpm
  • Top Speed - 145mph