The 1979 Triumph Bonneville represents a poignant chapter in British motorcycle history, standing as the primary flagship model for the short lived, worker-owned, Meriden Co-operative, who took control of Triumph from Norton-Villiers-Triumph in 1977 only to go into receivership 6 years later.

With its iconic styling, deep heritage, and distinct exhaust note, this 744cc parallel-twin was refined to survive tough modern environmental mandates while offering an authentic, mechanical experience. This year solidified the platform's adaptation to the modern era with upgraded electrical infrastructure and factory-custom variants.

The current owner has had this example for almost 30 years, wrenching on nearly every nut and bolt, but leaving it largely stock other than adding the Dunstall exhaust and Euro handlebars.

Historical Significance & Evolution

• The EPA Challenge: The "E" designation (as seen in the primary T140E model) marked a comprehensive redesign of the cylinder head and intake. These changes targeted strict United States emissions regulations, ensuring the British twin's survival in its most critical export market.

• The T140D Special: In 1979, Triumph introduced the highly stylized T140D variant to capture the factory-custom market. It featured striking black-and-gold paint, a "siamesed" 2-into-1 exhaust, and a wider rear tire on cast alloy wheels.

• Electrical Evolution: The 1979 models brought a long-awaited leap forward in reliability by making the Lucas electronic ignition standard. This greatly tamed the classic model's finicky starting habits and reduced maintenance requirements.

Production Run

1973–1983 (The 1979 model year introduced standard parallel EPA refinements)

Total Units Built

Approximately 20,000 machines completed across the core T140E architecture

Special Variants

~3,800 limited-edition T140D "Special" cruiser configurations produced

Market Status

Highly regarded as the final era of true Meriden-built classic twins before electric-start was added

Technical Specifications

Engine & Powertrain

• Engine Type: 445cc per cylinder / 744cc total air-cooled, four-stroke, parallel-twin (pushrod OHV)

• Performance: 49 to 54 horsepower @ 6,200 RPM (depending on territory tuning and compression ratio)

• Bore & Stroke: 76 mm x 82 mm (7.9:1 compression ratio optimized for lower emissions)

• Drivetrain: 5-speed manual gearbox utilizing a standardized left-hand foot shift arrangement

Chassis & Performance

• Suspension: Heavy-duty steel tubular "oil-in-frame" chassis equipped with long-travel telescopic front forks and twin Girling rear shocks

• Braking System: Dual-wheel disc system featuring 10-inch (254 mm) hydraulic disc brakes front and rear

• Curb Weight: Approximately 197 kg to 200 kg (435 lbs to 441 lbs) dry weight

• Top Speed: 111 mph to 118 mph (178 to 190 km/h)