The Triumph Bonneville is Triumph’s classic British roadster. It launched in 1959 as the T120, a 649cc parallel twin named after Triumph’s 214 mph speed record at Utah’s Bonneville Salt Flats. Today’s T120 runs a 1200cc twin, about 85% more displacement than the original.
This guide covers where the name came from, how each era of the Bonneville changed, what the 2026 range looks like, and whether a Bonneville makes sense as your first big bike. Every date and number comes from Triumph’s own pages or the sources listed at the end. Where sources disagree, I say so.
Where the Bonneville name comes from
In 1956, American racer Johnny Allen reached 214 mph on the Bonneville Salt Flats in Utah, on a streamliner built around a heavily modified Triumph Tiger T110 engine. Triumph’s own history page says the T120 was “named after Triumph’s 214mph landspeed record in 1956”.
The bike was designer Edward Turner’s last production design for Triumph. Triumph calls it his “design swansong” and dates the design to 1958. It came together so quickly that it missed Triumph’s 1959 catalogue.
The T120 (1959 to 1975): the original Bonnie
The first Bonneville was built at Triumph’s Meriden factory in England. Wikipedia lists its engine at 649cc. It was based on the Tiger T110 and came with that model’s optional twin Amal Monobloc carburettors and high-performance inlet camshaft as standard. Triumph sold it as “The Best Motorcycle in the World” and aimed it mainly at the United States.
The early bikes used a pre-unit engine, with the engine and gearbox as separate parts. They could reach 115 mph, but the power could cause high-speed wobbles in the single-downtube frame. The key changes that followed:
- 1963: unit construction, with the engine and gearbox in one stiffer, more compact unit, plus extra bracing at the steering head and swingarm.
- 1967: Triumph’s best year in the US, with an estimated 28,000 T120s sold.
- 1971: a new frame that carried the engine oil inside it, known as “oil in frame”.
- 1972: a five-speed gearbox became fully available.
The T120 also made its name in racing. Triumph says John Hartle won at the Isle of Man TT on one, and that in 1969 Malcolm Uphill lapped the TT course at more than 100 mph on a Bonneville.
The T140 (1973 to 1983): the 750 and the Meriden sit-in
Bigger bikes from rivals, above all Honda’s CB750 (the bike that created the superbike class), pushed Triumph to enlarge the engine. The T140 arrived in 1973 with a 724cc engine, soon bored out to 744cc, plus a five-speed gearbox and a front disc brake.
That same year, workers at Meriden began a sit-in that lasted until 1975 and kept Triumph twins off the market. They then formed the Meriden Motorcycle Co-operative, which built only the 750cc twins from then on. The 650cc T120 never came back.
Later T140s moved the gear lever to the left side for the US market, added a rear disc brake, then electronic ignition from 1979 and electric start from 1980. Production ended when the Meriden works closed in 1983.
The Harris Bonnevilles (1985 to 1988)
Businessman John Bloor bought the Triumph name. While his new company worked on its own bikes, he licensed Les Harris of Racing Spares in Devon to build the T140. These “Harris” Bonnevilles reached buyers from 1985 to 1988. They were not sold in the United States.
The Hinckley Bonneville (2001 to 2015): air-cooled and modern
Bloor’s Triumph Motorcycles, based in Hinckley, launched a completely new Bonneville in September 2001. It looked like the old bike but was a new design, with a 790cc air-cooled parallel twin. Triumph’s own history page dates the T100 version to 2002, so you will see both years quoted.
- 2005: the T100 moved up to an 865cc engine.
- 2007: every Bonneville got the 865cc engine.
- 2008 and 2009: fuel injection replaced carburettors, in 2008 for UK models and in the 2009 model year for US models, to meet emissions rules. Triumph styled the throttle bodies to look like carburettors.
This platform also gave Triumph a whole family of Modern Classics, including the Thruxton, the Scrambler (2006) and the Speedmaster.
The liquid-cooled Bonneville (2016 to today)
In 2016 the T120 name returned with an all-new, liquid-cooled 1200cc twin. Triumph followed it in 2017 with the 900cc T100. Triumph says the T120 takes its styling cues from the 1959 original while adding modern technology and riding capability.
Bonneville generations at a glance
| Era | Years | Engine | Built by |
|---|---|---|---|
| T120 | 1959 to 1975 | 649cc air-cooled parallel twin | Triumph Engineering, Meriden |
| T140 | 1973 to 1983 | 724cc, then 744cc parallel twin | Triumph, then the Meriden co-operative |
| Harris T140 | 1985 to 1988 | 744cc parallel twin | Racing Spares (Les Harris), Devon, under licence |
| Hinckley Bonneville | 2001 to 2015 | 790cc, then 865cc air-cooled parallel twin | Triumph Motorcycles (John Bloor) |
| T120 and T100 | 2016 to today | 1200cc and 900cc liquid-cooled parallel twins | Triumph Motorcycles |
| T40 | New for 2026 | 398cc liquid-cooled single | Triumph Motorcycles |
The original stat: 85% more engine, and now a single
We compared the first and current flagship engines. The 1959 T120 had 649cc. The current T120 has 1200cc. That is 551cc more, a rise of about 85% between 1959 and the 2016 relaunch of the T120 name. At the same time, the range has gone the other way: the new T40 has a 398cc single, the first single-cylinder engine in a line that had only used twins since 1959.
The Bonneville range today
Triumph’s US Bonneville page, checked on 1 November 2026, lists seven models:
- Bonneville T40 and T40 Black (all new)
- Bonneville T100
- Bonneville T120 and T120 Black
- Bonneville Speedmaster
- Bonneville Bobber
The T40 is the big news. Triumph’s spec page lists a liquid-cooled, single-cylinder, four-valve DOHC engine of 398cc, making 32 PS at 7,000 rpm. It comes with five riding modes, lean-sensitive cornering ABS and traction control, cruise control, and a round 4-inch TFT screen with map navigation. Triumph had not published a US price when we checked.
Is a Bonneville a good first big bike?
For many newer riders, it can be. Triumph describes the 900cc T100 as one of “the most accessible and advanced Bonnevilles ever made”, with an engine built for low and mid-range torque. The T40 goes further, with a smaller engine, low seat and rider aids aimed at, in Triumph’s words, “a new generation of Bonneville riders”.
The 1200cc T120, Speedmaster and Bobber are bigger, heavier bikes. If you are just off your licence, a test ride on the T40 or T100 first is a sensible step. Check local licence rules on engine size before you buy. If you are still learning the terms, our guide to what counts as a superbike explains where classic roadsters like the Bonneville sit.
FAQ
Why is it called the Bonneville?
Triumph named it after its 214 mph speed record set in 1956 at the Bonneville Salt Flats in Utah.
When was the first Triumph Bonneville made?
The T120 Bonneville launched in 1959. Triumph says Edward Turner designed it in 1958.
What is the difference between the Bonneville T100 and T120?
On the current models, the T100 has a 900cc twin and the T120 has a 1200cc twin. The T100 is lighter and easier for newer riders, while the T120 has more power and torque.
Is the Bonneville T40 a twin?
No. Triumph lists the T40 with a 398cc single-cylinder engine. Every earlier Bonneville used a parallel twin.
Where are Triumph Bonnevilles made?
The originals were built at Meriden in England. Modern Triumph is based at Hinckley, England. Wikipedia notes that, by 2014, some Bonneville models were built at Triumph’s factory in Thailand.
Is the Triumph Bonneville a good motorcycle for beginners?
The T40 and T100 suit newer riders best because of their smaller engines and easy handling. The 1200cc models are better as a second bike.
Sources
- Triumph: Our story, Bonneville family, for the 214 mph record, Edward Turner, the TT results, the T100 history and the 2016 T120, checked 1 November 2026.
- Triumph: Bonneville range (US), for the seven current models, checked 1 November 2026.
- Triumph: Bonneville T40, for the 398cc single, power, rider aids and pricing status, checked 1 November 2026.
- Wikipedia: Triumph Bonneville T120, for the 649cc engine, the missed 1959 catalogue, 115 mph, the 1963 unit engine, 1967 US sales, oil in frame and the sit-in.
- Wikipedia: Triumph Tiger T110, for Johnny Allen’s 1956 run on a modified T110.
- Wikipedia: Triumph Bonneville, for the T140 changes, the Harris bikes, the 2001 relaunch, 865cc, fuel injection and the Thailand factory.
Featured photo: 1959 Triumph Bonneville, by Rachel.dicerbo, CC BY-SA 4.0, via Wikimedia Commons.
