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Panther Model 120

Manufacturer	Phelon & Moore
Production	1959–1965
Engine	646 cc. ohv single
Power	27 bhp (20 kW) at 4,500 rpm
Transmission	Burman Four speed. Multi-plate clutch in oil
Brakes	8 inch front drum 7 inch rear drum
Tires	Front tyre 3.25 x 19 inch Rear tyre 3.50 x 19 inch
Wheelbase	59 inches (1,500 mm)
Dimensions	L: 83 inches (2,100 mm)
Seat height	28 inches (710 mm)
Weight	426 lb (193 kg) (dry)
Fuel consumption	55 mpg‑imp (5.1 L/100 km; 46 mpg‑US)

Overview

Yorkshiremen, Joah Phelon and Harry Rainer, patented the use of the cylinder and crankcase of a motorcycle engine as a stressed member of a motorcycle frame in 1900 and licenced the concept to Humber of Coventry, which used it on its motorcycles and forecars. Rainer died in a road crash in 1903 and Richard Moore joined Phelon and the company became P&M, manufacturing motorcycles with their own 500cc side-valve engine and Moore’s unique two-speed gearbox design.

In 1924, the company produced a 499cc overhead-valve, single-cylinder engine designed by Granville Bradshaw and the 1925 TT model was a ready seller. Tommy Bullus finished fourth in the TT that year on an almost standard model. A variety of other engine designs were developed, some using conventional frame designs, but production of the 498cc and 594cc Sloper singles continued. In 1945, the 594cc Sloper, by then known as the 110, was equipped with Dowty air-spring telescopic front forks. The Slopers were regarded as excellent sidecar machines and the 645cc 120, which was unveiled in 1958 with telescopic forks and swinging arm rear suspension, continued in production until 1966. It developed 27bhp and was equipped with a four-speed Burman BAP gearbox. Top speed in solo form was in excess of 80mph (129kph).

This 1964 120S was first registered in Brixton Hill, London, by George Clarke (Motors) Ltd. in May, 1964, and then to a private owner of Harwich, Essex, the following month. It changed hands to another Harwich owner in December, 1965, who brought it to New Zealand and registered it in Christchurch in November, 1966. Although its first registration in London lists it as a ‘Sidecar Bicycle’, there is no mention of a sidecar on its registration papers when it was first registered in New Zealand although the double adult is recorded as being with the bike in Dunedin in 1999. The private vendor from whom it was acquired for the NZ Classic Motorcycles collection in August, 2009, had restored the combination.

Development

The Panther sloper engine designed by Granville Bradshaw remained unchanged for 25 years and the 650 cc 'heavyweight' had many of the Model 100 components. The increased capacity was achieved by boring out the Model 100 cylinder by 1 mm and increasing the stroke by 6 mm. As well as increased low speed torque this improved acceleration and top end cruising speed.

This put additional strain on the main bearings and crankcases, leading to reliability problems. The 120 also suffered with lubrication problems from the large sump cast into the front of the engine. Oil was pumped to the top of the sloper engine but return was erratic and oil consumption very heavy. The main shaft was redesigned with larger ball journal main bearings, A smaller exhaust valve combined with a larger Amal monobloc carburettor gave the Model 120 28 bhp at 4500 rpm, an increase of 4 bhp over the Model 100.

Motorcycle sidecars were popular at the end of the 1950s, so the Model 120 was provided with a purpose built sidecar chassis, connected by a three point mounting which provided minimal alignment problems. The sidecar wheel was interchangeable with the motorcycle wheels and had swinging arm suspension with an Armstrong shock absorber. A trailer with a towbar was also provided as an option.

The end

By 1962 Phelon & Moore were in financial trouble and went into receivership. The Model 120 stayed in production for as long as the supply of spare parts lasted, but they finally ran out in 1966 and the company folded. It wasn't quite the end for the big Panther, however, as they were cheap and economical and continued to sell for another year after production ended. Panther Model 120's are still being maintained and used regularly to this day by enthusiasts.

Gallery

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  Model 120, right side

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  Model 120, left side