The original Triumph Bonneville was popular (particularly in its early years) for its performance compared with other available bikes. Although its motor was later enlarged to 750 cc, in the late 1970s and early 1980s sales abroad greatly suffered in competition with more modern Japanese motorbikes from Honda and other manufacturers. Domestically, however, the T140 remained the best-selling 750 cc motorcycle against more sophisticated Japanese and Italian opposition , picking up the prestigious Motor Cycle News Machine Of The Year award in 1979.
 T120 Bonneville
Main article: Triumph Bonneville T120
The original Triumph Bonneville was a 650 cc parallel-twin (two-cylinder) motorcycle manufactured by Triumph Engineering and later by Norton Villiers Triumph between 1959 and 1974. It was based on the company's Triumph Tiger T110 and was fitted with the Tiger's optional twin 1 3/16 in Amal monobloc carburettors as standard, along with that model's high-performance inlet camshaft. Initially it was produced with a pre-unit construction engine which enabled the bike to comfortably achieve 115 mph without further modification, but later (in 1963) a unit construction model was introduced which was stiffer and more compact, including additional bracing at the steering head and swing arm. The steering angle was altered and improved forks were fitted a couple of years later, which, together with the increased stiffness enabled overall performance to match that of the Bonneville's rivals. Later T120 Bonnevilles used a new frame which contained the engine oil instead of using a separate tank; this became known as the oil in frame version. The T120 engine, both in standard configuration and especially when tuned for increased performance, was popular in café racers such as Tribsas and particularly Tritons.
 T140 Bonneville
Main article: Triumph Bonneville T140
The early 650 cc capacity production T120 Bonneville, often known as the duplex frame model, was replaced in the early 1970s by the T140 Bonneville, the same basic machine but with a 750 cc engine. Refined from the later 'oil in frame' version of the T120, the first few T140s, designated T140V, featured a larger-capacity engine of 724 cc, a five-speed gearbox option and indicators, but still retaining drum brakes and kick-start. Shortly after, the engine was further bored out to 744 cc and front disc brakes were fitted (using single discs until 1982). In 1975, along with engine modifications, the gearchange lever was moved from right to left to comply with new regulations mandated for the American market and a rear disc brake fitted. Several T140 models followed featuring various modifications and refinements including electric starting from 1980 until production ceased with the closure of the Meriden works in 1983.
Although this should have been the end of the Bonneville, as it turned out it was not. Triumph Motorcycles was acquired by businessman John Bloor, who licensed a company called Racing Spares in Devon, run by Les Harris to manufacture the T140 Bonneville. These continuation bikes are known as the 'Devon Bonnevilles', which did not reach the market until 1985, and were not sold in the U.S. Production ended in 1988.
 New Bonneville
A completely new Triumph Bonneville 790 was debuted in 2001 by Bloor's Triumph Motorcycles Ltd. Originally built exclusively in Hinckley, England, some models are now produced at the company's Thailand manufacturing facility (which also makes components and accessories for various Triumph bikes). The new "Bonnie" strongly resembles the earlier models in style and basic configuration, but with entirely modern engineering. At the debut the new version was given a 790 cc parallel-twin engine, with the up-spec T100 receiving a 865 cc engine. From 2007 on, all Bonnevilles received the 865 cc engine. Through 2007, all engines had carburettors; electronic fuel injection was then introduced to the 2008 models in Britain and to United States models in the 2009 model year, in both cases to comply with increasingly stringent emissions requirements. "Dummy" carburettors have been added to the 2009 models to retain the original vintage styling of previous years.
All the bikes in Triumph's current "Modern Classics" line are based on the new Bonneville, including the SE, T100, Thruxton, Scrambler, America, and Speedmaster.
In 2006, Triumph launched the "Sixty-8" line of Bonneville accessories, offering vintage and modern-style items including seats, seat covers, cam covers, sprocket covers, petrol tank covers, tank badges, panniers, and other items to allow Bonneville owners the opportunity to customise their bikes for considerably less cost than traditional customisations.