1983 TSS-AV |
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| Manufacturer | Triumph |
|---|---|
| Production | 1982–1983 |
| Engine | 749 cc (45.7 cu in) twin |
The T140W TSS was the last motorcycle model made by Triumph Engineering at their Meriden factory.
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Designed to appeal to the US market, the TSS had an eight valve Weslake Engineering cylinder head developed by American racer Jack Wilson from a design originally commissioned by the Rickman Brothers in the 1970s.
The crank was a fully machined single forging with increased big end diameter making it much stiffer and better-balanced, and producing one of the smoothest running motorcycles in the Triumph range. The new eight-valve cylinder head had smaller valves set at a steeper angle and recesses in the pistons allowed a 10:1 compression ratio.
UK models had a pair of 34 mm Amal MkII carburettors while the export models had Bing constant velocity carburettors. Other changes from the standard T140E included offset connecting rods, steel-linered alloy barrels, a strengthened swinging arm, and a high output three-phase alternator.
A TSS raced by Jon Minonno for Texan Jack Wilson's Big D Triumph dealership achieved outstanding results in the Battle Of The Twins races for 1981–1982.
According to the Triumph build books, held by the Vintage Motor Cycle Club, the first TSS was built on 27 October 1981 for the North American export market.
Launched in 1982 with an electric starter, the eight valve engine proved unreliable due to engineering problems with Wills sealing rings used instead of a conventional cylinder head gasket. Morris alloy wheels were an option with dual Automotive Products Lockheed disc upfront as standard. The fins of the black painted engine were polished although, like the Triumph TR65 Thunderbird, many alloy cycle parts that had in the past been bright polished or chromed were now painted satin black. Mudguards were stainless steel as were the Italian Radaelli rims for the wire-spoked wheel option.
Unlike most of Triumph's models, no USA style with high handlebars and two-gallon tank was produced, all models coming with the Italian-sourced four-gallon tank and low handlebars as well as the newly introduced alloy 'dog leg' clutch and front brake levers. The USA did receive a black paint scheme with gold-lined red 'wings' along with Italian-sourced mufflers and the Bing carburettors. A one-off variant in line with the Triumph Bonneville T140EX Executive was produced for a London dealer, albeit again in gold-lined black, but with the Executive's standard Brearley-Smith 'Sabre' fairing and luggage by Sigma. All TSS were shod with Avon Roadrunner tyres.
Only 112 TSS bikes were actually exported by Triumph, as on 26 August 1983 the factory at Meriden went into voluntary liquidation. Over 400 TSS models were made in total.[1]
The model was generally well-received by the press although a long term test by Motor Cycle Weekly revealed the porous cylinder head problem and an unusual occurrence of wet weather braking failure. In an interview in US magazine, Motorcyclist, Meriden's Director of Engineering, Brian Jones revealed that the epoxy coating on the cylinder head disguised the porosity problem from their factory testers.
Fitting an eight-valve engine in an anti-vibration frame was first mooted by the factory at the 1981 Earls Court motorcycle show on the prototype super-tourer, TS8-1. Now displayed at the London Motorcycle Museum, the TS8-1 had plastic bodywork by Ian Dyson of contracted stylists, Plastic Fantastic.
For the unrealised 1983–1984 range, the TSS was to have had Meriden's 'Enforcer' frame as standard where the engine was rubber-mounted in this special anti-vibration frame. Styling changes included the adoption of the Triumph T140 TSX rear mudguard, in stainless steel, and side panels from the same model with a similarly styled TSS badge affixed. These replaced the original side panels which had been extended to cover the Bing carburettor linkages on the USA export models. A plastic 'ducktail' seat unit was mounted above the shortened rear mudguard of the projected 1983–1984 civilian model and rear set footrests, brake and gear shift mechanisms fitted. Police TSS AV retained the standard footrest/control arrangement as well as conventional cycle parts over the ducktail and TSX parts. Due to the height clearance limitations caused by the engine jogging about its rubber mounts within the AV frame, the shorter Amal Mk2 carburretors instead of Bings were fitted.
Only three examples of the TSS AV in police and civilian specification were ever made (and one bare frame) including one made for the late Chris Buckle, proprietor of former Triumph dealers, Roebucks Motorcycles of Rayners Lane, North London, UK. Not quite to the envisaged 1984 specification, his was made on 27 June 1983 and is, according to the factory production records held by the Vintage Motor Cycle Club, the last complete Triumph ever made by Meriden. This is now on display at the National Motorcycle Museum in Solihull, West Midlands close by to where the Meriden factory was.
Another prototype from the unrealised 1983/1984 range, a TSS engine, with Bings, in Triumph T140 TSX cycle parts was to be marketed as the TSX8, the original four-valve version renamed as the TSX4. Wayne Moulton who designed the TSX had originally done so with the 8-valve TSS engine in mind.