Douglas 1947 Model T35: Collectable

Date 13.1.2014

Presented by
  • Motorcycle Trader

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Douglas 1947 Model T35

DOUG OF WAR

Of all the British motorcycle manufacturers re-entering the market after the end of World War II, the return of Douglas was perhaps the most surprising.

Unlike other companies, Douglas, during the 1930s, lurched from one financial crisis to another, barely producing any motorcycles during the decade.

But the war improved Douglas’ fortunes considerably and among its wartime products was a portable generator unit produced for the War Office. When the war was over, employing this 348cc flat-twin overhead valve engine in a motorcycle seemed an obvious solution.

POLISHED FLAW

Designed by George Halliday, the T35 was one of the most innovative motorcycle designs to emanate after World War II.

Most post-war motorcycles were essentially modified pre-war designs but, with the T35, Halliday created a machine completely unrelated to earlier designs. As on the BMW, he placed the wartime generator flat-twin transversely but, instead of the BMW’s shaft, it featured a chain final drive. The T35 was unveiled to the press in September 1945 but it didn’t actually enter production until 1947.

The T35 engine was a 60.8 x 60mm overhead valve design and initially produced 21 horsepower at 6000rpm. The design was fairly ordinary with cast-iron cylinder heads and barrels, wet-sump lubrication and each cylinder carrying an inward-facing Amal Type 4 carburettor.

The gearbox was a built-in unit with the engine and incorporated an automotive-style, single-plate clutch, while a pair of bevel gears at the end of the gearbox allowed the chain final drive.

The engine may have been unremarkable but it was smooth and provided a low centre of gravity. The main problem was that, as a generator, it was designed to work at a constant speed and was not particularly happy coping with the varying loads and speeds demanded by a motorcycle. Combined with dubious workmanship and poor quality control, the early T35 soon gained a reputation for unreliability.

SUPERIOR AND INFERIOR

Although the engine was problematic, the chassis was extremely advanced for the day. While many other manufacturers were dusting off old rigid-frame singles, the Douglas had springing front and rear. And this suspension wasn’t traditional either, with torsion bar springing for the box-section steel swingarm and leading-link Radiadraulic forks.

Halliday originally intended a torsion-bar front fork but the construction proved too complicated. The rear torsion bars were carried inside the lower frame tubes, connected by a linkage to the swingarm. The twisting action of the bar controlled the rise and fall of the swingarm. Although there was no damping, the handling of the Douglas was satisfactory, especially by the standards of the late 1940s.

The Radiadraulic fork was equally pioneering. Short leading links pivoted at the rear of the fork tubes with the springs and damping contained inside the tube. As the front axle was pivoted, the front mudguard didn’t rise and fall with the wheel so it had to be mounted quite high.

But the parallel leading link isolated the fork from dive under braking and, with low unsprung weight, the Douglas Radiadraulic fork soon became extremely popular with grass track racers. With more than 150mm of fork travel, a Douglas rider could surprise his mates on rigid-frame models by comfortably riding over bricks and curbs. The wheels on the T35 were 19-inch items front and rear and the wheelbase a short 1380mm. But the T35 was no lightweight at 180kg and performance was modest.

PROBLEM PLAGUE

Despite its innovative frame and suspension, the T35 was unfortunately not a very good motorcycle. Not only was the engine unreliable, it leaked oil, the frames fractured, and the links in the suspension wore prematurely. But, to its credit, Douglas was quick to rectify problems.

The improved Mark III appeared during 1948 and the Mark V followed it in 1951. For some reason, there was never a Mark II or Mark IV.  The Mark V became the Dragonfly in 1955, with longer, leading-link Earles forks and conventional swingarm rear suspension.

The engine was essentially unchanged and was always a slogger rather than a performer. Always expensive and slow, during the mid-1950s nobody really wanted the Duggie and the final Douglas rolled out of the Kingswood factory in March, 1957. With only 2321 post-war twins manufactured, a Douglas today is a rare commodity. As one of the more fascinating British twins, though, they now have a strong following.

Many thanks to Allen and Lorraine Smith of the Australian Motorcycle Museum, Haigslea, Queensland, for the use of the 1947 T35 pictured.

THE VALUE PROPOSITION

Price when new: £58 15s (1947)
Now: $7000 – $13,000

FAST FACTS

Douglas 1947 Model T35

• Established as a motorcycle manufacturer in Bristol in 1907, Douglas was also the only motorcycle company in the British West Country. In addition to motorcycles, Douglas built cars, tractors, scooters, industrial engines, aero engines, aircraft, electric floats, and drain covers.

• Douglas’ first TT win, a first and second in 1912, led to a contact to supply 25,000 WD machines to the British Army during World War I. The first BMW engine was almost an exact copy of the 1913 Douglas Type B 500cc twin, except it was turned sideways in the frame.

• Success for Douglas continued throughout the 1920s and a Douglas was the first motorcycle to top 160km/h at Brooklands. Douglas retained the fore-and-aft engine layout until 1934. It then produced the shaft-drive Endeavour, similar in concept to the BMW, but this was a miserable failure. The company almost disappeared following the death of William Douglas in 1937.

• The transverse, flat-twin Douglas continued to early 1957. After  motorcycle production ceased, Douglas maintained an association with motorcycling through until 1982, first assembling Vespas, then importing Gilera mopeds.

WANT TO KNOW MORE

• Established as a motorcycle manufacturer in Bristol in 1907, Douglas was also the only motorcycle company in the British West Country. In addition to motorcycles, Douglas built cars, tractors, scooters, industrial engines, aero engines, aircraft, electric floats, and drain covers.

• Douglas’ first TT win, a first and second in 1912, led to a contact to supply 25,000 WD machines to the British Army during World War I. The first BMW engine was almost an exact copy of the 1913 Douglas Type B 500cc twin, except it was turned sideways in the frame.

• Success for Douglas continued throughout the 1920s and a Douglas was the first motorcycle to top 160km/h at Brooklands. Douglas retained the fore-and-aft engine layout until 1934. It then produced the shaft-drive Endeavour, similar in concept to the BMW, but this was a miserable failure. The company almost disappeared following the death of William Douglas in 1937.

• The transverse, flat-twin Douglas continued to early 1957. After  motorcycle production ceased, Douglas maintained an association with motorcycling through until 1982, first assembling Vespas, then importing Gilera mopeds.