Reference: When was it that? Velocette GTP

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It was not until 1909 that Veloce Limited had their first own-designed motorcycle on the market, an unorthodox but ingenious unit-construction four-stroke single that failed to attract much attention. As a result they had to diversify by introducing another, more simple four-stroke, not unlike the contemporary Triumph of that period. It too was not very successful, so with a growing interest in the lightweight motorcycle, or motorcyclette as it was then known, they turned their attention to the production of a 206cc two-stroke.

The basic requirements for a motorcyclette were that it should be light in weight, cheap to purchase and economic to run, and in each of these respects the new two-stroke acquitted itself well.

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When it appeared in 1913, it represented the first of a long series of two-stroke models with the name Velocette on the tank. A quality product right from the beginning, it was one on which the company built a good reputation.

Velocette GTP two strokeOf conventional three-port design and using a deflector piston, the two-stroke models made from 1913 to 1929 were all of the overhung crankshaft type, with an outside flywheel and a single bobweight and outboard connecting rod assembly. Lubrication was by means of an independent oil supply carried within a crankcase compartment, from which it was dispensed by exhaust pressure, or in the case of the more expensive models, by a mechanical pump. Veloce Limited were never in favour of using petroil.

A win in the 1926 Junior TT had put the company on its feet and by 1929 they had four overhead camshaft models in their catalogue, along with a couple of two-strokes. The latter comprised the 249cc Model U and its sports counterpart, the Model USS. Priced at £38, the Model U had sold reasonably well since its debut a year before, but stocks needed to be cleared to make way for an entirely new model. Appropriately, they were renamed Model 32 and sold at the reduced price of £32. Less than 300 of the higher priced (£42) USS models had been sold and this too was to be discontinued at the end of the 1929 manufacturing year.

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Velocette 1939 GTPWhen it made its first appearance at Olympia in early December, the new Model GTP two-stroke differed in a great many respects from its predecessors. The engine was no longer of the overhung crankshaft design but followed more conventional lines in having the crankshaft assembly supported at both ends, with a two-piece crankcase that could be separated vertically. The crankcase also contained a mechanical pump, drawing its oil supply by gravity from a separate compartment within the petrol tank. The three-speed hand change gearbox was basically similar to that used previously, although there was now a positive means of gear indexing by means of a spring loaded plunger, that absolved the gearchange gate of this function. The clutch operating mechanism had been changed too, using an internal bell crank arrangement rather than an external cam ring and lever, that resembled a frying pan in profile. There were some changes in the cycle parts too. The frame was no longer of the full cradle type and the Webb front fork was fitted with a steering damper and side friction dampers, like those on the USS sports models.

Velocette model u engineBy far the biggest diversion from current practice was the use of coil ignition, in preference to a magneto. Veloce Limited argued that as two in every three cars now used this method, it was logical that motorcycles should follow suit. The coil was mounted vertically within a circular compartment formed in the underside of the petrol tank, with the contact breaker assembly driven off the extreme right hand end of the crankshaft. To keep the battery charged, a pulley cast into the rear of the large external flywheel drove a 3-brush dynamo mounted in the rear engine plates, by means of a flat belt. Both Lucas and Miller electrical equipment were used initially, but eventually Miller took over completely. It was alleged that in the event of a flat battery, the machine could be started by running with it in bottom gear; although it is doubtful whether any but the very fit (or someone living on a hill) could ever raise sufficient charge from the dynamo to set things going!

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Keen pricing was essential as the country was in the grip of economic recession. The GTP retailed at £38, with full electric lighting equipment,electric horn and licence holder. Veloce were one of the first to include the cost of all the add-on, but obligatory 'extras' in the purchase price. If required, a touring rear carrier could be supplied for a reasonable extra 13/6d (67.5p). Nicely styled and finished in the company's characteristic black and gold, the new GTP was undoubtedly a handsome machine in anyone's eyes. It was quite light to manoeuvre too, weighing only 222 lbs. Road tests published in the two motorcycling weeklies were impressive and many soon found that any apprehension about the use of coil ignition was unjustified.

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The GTP continued in production until the outbreak of World War II, its specification being uprated from time to time. In 1932 the cast iron cylinder head was replaced by one of light alloy, and at the same time the throttle was linked to the oil pump – long before the Japanese 'reinvented' throttle-controlled lubrication. Optional twin upswept exhaust pipes were also available around this time.

In 1934 the transfer port arrangement was changed, so that the incoming charge passed through a 'window' in the piston to help cool the underside of its crown. Later that year, a 4-speed footchange gearbox was introduced, which necessitated lightening the external flywheel and at the same time providing it with a detachable centre. It also permitted the primary chain to be fully enclosed within an oilbath chaincase. The final touch came during the last years of manufacture, when a much deeper and more stylish petrol tank was adopted.

Velocette logoA few GTP models were fitted with magneto ignition, especially a small batch made during 1945-6, no doubt from parts left over at the factory. The magneto was mounted above the dynamo and driven from a sprocket on the contact breaker taper; the drive being fully enclosed within a KSS-like alloy chaincase. Irrespective of what ignition system was used, the GTP was definitely one of Britain's best two-strokes and today, is a much sought model. If you are lucky enough to have one, you will know why! bike

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