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John Player Norton



John Player Norton early version



It was 1973 and the riders were lining up for the Trans-Atlantic Match Races. The Easter Trans-Atlantic Match Races were a big deal at the time drawing huge crowds and television coverage. They would have races Friday, Saturday and then skip Sunday and then race again on Monday at three different tracks, Brands Hatch, Mallory Park and Oulton Park. The John Player Special of Peter Williams wasn't given much of a chance. No one doubted his riding ability but the bike was powered by a primitive Norton air cooled pushrod engine with a separate gearbox and he was up against the three cylinder two strokes of Kawasaki and Suzuki as well as the British BSA and Triumph triples. Williams and the bike were outstanding. He won three races and finished first overall.

The John Player Norton was a groundbreaking motorcycle in many ways, not the least of which, was the fact that it was the first racing team to be fully supported by an outside sponsor. The backing by Imperial Tobacco was to start the avalanche of cigarette money that supported race teams for decades to come. The bike was much more than this though, it's Avant Guard engineering concepts were to prove that a bike could be made competitive with un-competitive horsepower. Apart from the unlikely Rotary, it was the last factory racing Norton.



Peter Williams at the Isle of Man


Peter Williams was highly regarded in the racing world, he was a world-class rider and a talented engineer, but even his most ardent supporters must have been skeptical when he set out on his project. Peter's real job was as an engineer at Norton and the tiny race department had been given a budget, thanks to John Player's sponsorship, to build a race bike. What they had to work with was not inspiring. The ageing Norton Commando had long since lost its mantle as the top performer on the street, the Japanese two and four-stroke multis had seen to that. Ironically, it was the antiquated powerplant that made them think out of the box.



Peter Williams at the Trans Atlantic Match races


Norton's immediate rivals, BSA and Triumph, had been having considerable success on the track with their triples. This had not gone unnoticed by Norton chairman Dennis Poore and the new sponsorship could not have come at a better time. Poore was a former car racer and used some of his contacts to obtain the John Player backing.



The one piece bodywork could be quickly removed

The Monocoque bikes

The team started with a relatively conventional bike in 1972, but Williams decided that an unconventional approach was required to make the pushrod engine powered racer competitive. Sets of parameters were laid out for the 1973 bike. It was to have a Monocoque frame, made from stainless steel, a small frontal area and a low centre of gravity. Peter also said "We generated a reduced polar moment by placing the centre of gravity in the right place close to the centre of mass." Triple disc brakes were employed and the bike was one of the first, if not the first, to use cast wheels.



The Monocoque bike had 'panier' fuel tanks


The historical specifications show that the weight was 154 kg. This may have been the case, but it does seem a bit light considering stainless was used rather than light alloy. Stainless steel was used primarily for cost reasons but it may also have been that the expertise required to build a monocoque from alloy, was not readily available.



Every effort was made to lower the centre of gravity


As well as the Match races success, Williams won the 750 Formula Isle of Man TT with a record lap of 107.2 mph. He then beat Barry Sheene (Suzuki) at Cadwell Park. One bike had been readied for Williams to contest the 1973 Daytona 200 but had carburetion problems in the race. Norton-Villiers-Triumph wanted to cash in on this success and marketed a John Player Special road bike. It was basically a standard Commando dressed up but it didn't have the striking presence of the fully faired race bike. It was a lost opportunity.



The frame was a major work


1973 was the only year that the monocoque bike was raced. A tubular space frame was developed for 1974. It seems very odd that such a daring concept, and one that was almost immediately successful, would be abandoned. Williams believes it was a political decision and he strongly believed in the monocoque. Peter retired from racing in 1974 after an accident and later designed and developed Formula 1 car engines for Cosworth Engineering, which were used by McLaren and Benetton in 1993.



The 'cosmetic job' John Player Special road bike was a lot less inspiring
Image: MidAmerica Auctions

Monocoque bike specifications

Engine: 745cc (73×89mm) air-cooled parallel twin cylinder four-stroke; Lucas electronic ignition
Power Rating: 74 hp @ 7000 rpm
Valves: 2 per cylinder, overhead, pushrod activated
Fuel System: two Amal GP carburetors
Transmission: 5-speed, chain primary and final drive
Suspension: telescopic forks (front); swing arm (rear)
Brakes: twin discs (front); disc (rear)
Wheels: 18 inch cast aluminum (front & rear)
Weight: 340 lb (154.2kg)
Maximum Speed: 160 mph



Tubes were used instead of the Monocoque for 1974

The space frame bikes

The trellis frame was lighter than the monocoque and the mechanics preferred it as it was easier to work on the engine, but Williams said the intention was to build a considerably lighter version for 1974, presumably from alloy. The layout was very similar with a load-carrying backbone surrounding the engine. The second-generation 749cc Commando engine replaced the old long-stroke (73×89mm) unit and although it had a bit more power, it was never fast enough to challenge the multi cylinder water-cooled opposition. Williams and JPN second rider, Dave Croxford, were both unable to match the lap times they had set on the monocoque bike.

Space frame bike specifications

Engine: 745cc (73×89mm) air-cooled parallel twin cylinder four-stroke; Lucas electronic ignition
Power Rating: 78 hp @ 7500 rpm
Valves: 2 per cylinder, overhead, pushrod activated
Fuel System: two Amal GP carburetors
Transmission: 5-speed, chain primary and final drive
Suspension: telescopic forks (front); swing arm (rear)
Brakes: twin discs (front); disc (rear)
Wheels: 18 inch cast aluminum (front & rear)
Weight: 331lb (150.2kg)
Maximum Speed: 165 mph



The dimensions were almost identical to the monocoque bike

1976 Norton 750 Cosworth Challenge

Norton-Villiers-Triumph saw the futility of continuing racing with the Commando engine and Dennis Poore commissioned Cosworth to build a water-cooled, DOHC, fuel injected parallel twin. The engine was also planned as a replacement for the Commando road bikes. It was essentially two cylinders from the highly successful Cosworth V8 Formula 1 engine. The engine was designed to be part of the frame and on paper it looked like it had plenty of potential.



The Cosworth engined Challenge


However, cooling problems plagued the initial motors and by the time the engine was tested and ready, Norton-Villiers-Triumph was in financial trouble. Although the Commando had been a relatively good seller, sales for the group as a whole were poor. Low productivity and militant union actions contributed to the downfall and the factory closed in 1978.



The Cosworth engine looked to be mounted higher than necessary.
Image: TheWorldofMotorcycles.com


The NVT Cosworth and the Monocoque bike. Notice the differance in height


The bike was raced briefly with an NVT badge before the closure. Cosworth had built 30 engines before Norton's collapse and some of them were bought by Quantel. Bob Graves of Quantel, also a director at Cosworth, revitalised the motor in the mid 1980's and had Exactweld build a chassis around it. The engine was taken to 823cc. Australian GP rider Paul Lewis took the bike to second place in the Daytona Battle of the Twins race, behind the Works Ducati of Marco Luchinelli in 1976. In 1988, UK rider Roger Marshall won the BOT race, beating the works Ducatis.



Paul Lewis on the Quantel bike

Cosworth bike specifications

Engine: 747cc (86×65mm) water-cooled Cosworth JAA 360-degree parallel-twin four stroke
Power Rating: "at least 110″ hp @ 10,500 rpm
Valves: 4 per cylinder, twin overhead-camshafts driven by cogged belt
Fuel System: fuel injection
Transmission: 5-speed, chain final drive
Suspension: telescopic forks (front); cantilever with monodamper under the engine (rear)
Brakes: twin discs (front); disc (rear)
Wheels: 18 inch cast aluminum (front & rear)
Weight: 375 lb (170 kg)
Maximum Speed: 171 mph



The Cosworth engined Quantel bike


A replica JPN

A new JPN

Today, Peter Williams Motorcycles are building exact replicas of the JPN bikes. Only 25 of the monocoque-framed Commandos will be built and you will need £65,000 to procure one. The new bikes will be the same as the 1973 bikes, the main difference being that CAD and CNC laser cutters will considerably reduce the 12 weeks each frame took to construct on the originals. Only 3 JPN Monocoques were ever built (plus one prototype), largely due to the labour involved in hand building the complex frame. The original bikes are valued at over £250,000 each.
For more information, info@peterwilliamsmotorcycles.com or telephone (+44) 01327 220 534.

Written by Paul Harmon, 31-1-18
References: Designed to Race - Peter Williams, 8 May 2012 by Peter Williams


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