Triumph Bonneville – Born to be Wild

Launched in 1959 and named after Triumph’s record-breaking runs on the Bonneville Salt Flats, the Bonneville was more than just a faster Tiger. It was a statement—Triumph’s attempt to dominate the American market with a parallel twin that looked lean, sounded mean, and could break the ton straight off the showroom floor.

The Bonneville’s Origins: Built for Speed

The Bonneville T120 was born out of the Tiger T110, itself an evolution of the legendary Speed Twin. But whereas the Tiger had one Amal carburettor and a more docile tune, the Bonneville came out swinging with twin Amal Monoblocs, higher compression, and racier cam timing.

Under the tank, the 649cc OHV parallel twin made 46 bhp (34 kW) at 6,500 rpm. With just 180 kg (wet) to move, that meant 0–60 mph in under 7 seconds, with a true top speed of 115 mph.

Key Specs: Triumph Bonneville T120 (1959)

• Engine: 649cc air-cooled OHV parallel twin, 360° crank

• Carbs: Twin Amal Monoblocs

• Power: 46 bhp @ 6,500 rpm

• Gearbox: 4-speed (later 5-speed)

• Frame: Tubular steel duplex cradle

• Brakes: Drum front and rear (7-inch)

• Weight: ~180 kg (wet)

• Top speed: ~115 mph

It had a snappy throttle, high-frequency vibration, and just enough oil leaks to mark its territory. But it was one of the best-handling machines of its time—light, narrow, and perfectly suited to the winding roads of Britain, but also found ready acceptance on the open highways of America.

Bonneville vs. Tiger: What’s the Difference?

The Bonneville and the Tiger 100/T110 models shared much of their architecture, but they served different purposes. The Tiger was a gentleman’s fast tourer—smooth, simple, and reliable. The Bonneville, with its twin carbs and hotter cam profile, was a sportier machine aimed at performance riders.

Model	Engine	Carb Setup	Power	Gearbox	Top Speed	Notes
1958 Tiger T110	649cc OHV twin	Single carb	~42 bhp	4-speed	~105 mph	More docile, easier tuning
1959 Bonneville T120	649cc OHV twin	Twin carbs	46 bhp	4-speed	~115 mph	More aggressive, sportier ride

The Bonneville became the café racer’s weapon of choice. It was fast, light, and easy to mod. The Tiger remained the choice for riders who liked their thrills without the fuss.

Evolution Through the 1960s: The Golden Years

Throughout the 1960s, Triumph refined the Bonneville. In 1963, the model received unit construction—a cleaner, stiffer design that integrated engine and gearbox into a single casing. Handling improved. So did oil containment.

By 1969, a twin leading-shoe (TLS) front brake was introduced for better stopping power. In 1971, Triumph launched the controversial “oil-in-frame” chassis—raising the centre of gravity but increasing oil capacity and frame rigidity.

You either loved the new tall frame and extra oil capacity—or you hated the awkward seat height and slightly altered handling.

Despite the changes, the Bonneville remained the crown jewel of British motorcycling.

The 1970s: Slowing Down in a Fast World

The 1970s marked a turning point. The 1973 Honda CB750 made the Bonneville look outdated almost overnight: four cylinders, electric start, disc brake and oil-tight reliability. Triumph scrambled to compete.

In response, the T140 Bonneville was born, with a 744cc engine, 5-speed gearbox and front disc brake. It was quick, torquey, and better equipped, but it couldn’t quite match the performance or polish of its Japanese rivals.

Key Specs: Triumph Bonneville T140 (1973–1983)

• Engine: 744cc air-cooled OHV parallel twin

• Power: 49 bhp @ 6,200 rpm

• Gearbox: 5-speed

• Brakes: Single front disc, rear drum (later dual discs)

• Weight: ~190–200 kg (wet)

• Electric start: Optional (after 1980)

• Top speed: ~110–115 mph

Triumph also produced lower-cost versions like the TR7 Tiger—single-carb Bonnevilles with simpler maintenance but less flair.

The Collapse: 1983

Despite passionate fans and strong branding, Triumph couldn't hold off the wave of competition and internal dysfunction. After years of financial struggles, production delays, and outdated models, the Meriden factory closed its doors in 1983. The Bonneville faded into legend, but not into obscurity.

Why the Original Bonneville Still Matters

Between 1959 and 1983, the Triumph Bonneville evolved from a record-inspired speed machine to a British cultural icon. It wasn’t the most refined or reliable bike of its time. But it was fast, beautiful, and full of character.

Compared to the Tiger, the Bonneville was always the sharper blade—the sportier twin, the racier choice. Today, the original Bonneville isn’t just a classic motorcycle—it’s a reminder of when bikes were raw, mechanical and full of soul...