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Bonneville History (below)

TRIUMPH BONNEVILLE
The name is the same, and so is the format - a torquey twin-cylinder engine, an easy-handling chassis and lean, classical styling. In bringing back the Bonneville, one of the best loved names in motorcycling, Triumph has recreated the look, the feel and the spirit of our most famous parallel twin, while bringing the concept right up to date.

Few motorcyclists will need reminding that for many years the Triumph Bonneville was one of the stars of the motorcycle industry. The original T120 Bonneville was launched in 1959 as a high-performance, dual-carburetor version of Triumph's existing 650cc twin and named after the record-breaking feats on the Bonneville Salt Flats by Johnny Allen*.  The T120 was a huge hit for Triumph, especially in the USA and remained successful until production eventually ceased in 1983.

We are confident that the new Bonneville will appeal right across the motorcycling spectrum. Naturally we hope that its famous name, classic styling and twin-cylinder character will make it attractive to many of those who have ridden - and in many cases still ride Triumph twins from the past. However the new Bonneville is also very much aimed at riders of all ages, both male and female, who are simply looking for an enjoyable, good looking, practical machine with lively performance, pleasant power characteristics and excellent handling.

TECHNICAL DETAILS
From the outset, Triumph's intention with the Bonneville was to produce a machine that combined the old model's timeless appeal with modern technology. From the old machine, we wanted authentic styling, a parallel twin engine and to replicate as much as practically possible the feel and sound that forged the Bonneville legend. This meant using, for example, a 360-degree crankshaft (pistons rising and falling together) and a twin-shock rear suspension system.

One of our design team's first tasks was to decide which Bonneville from the past should become the inspiration for the new bike. This was not easy, given that the model spanned almost three decades, incorporating countless styling and technical changes - It is rare for two Bonneville enthusiasts to agree about which was best!  After much debate it was decided that the T120 Bonneville of the late Sixties could be regarded as representing the peak of the model's development, taking into consideration factors including performance, styling and position in the market. The new bike is very close to its forebear not only in its look, but also in its geometry and physical size.

Engine
The main requirement for the engine was that it should have a broad spread of power, to give effortless acceleration plus strong performance whether solo or carrying a passenger. Traditional capacities of 750cc and even the original 650cc were considered before 790cc was chosen. The 86mm bore size gives good breathing in conjunction with the four-valves-per-cylinder layout, while the 68mm stroke allows a long connecting rod that helps to minimize secondary vibration. As well as the desired low and midrange performance, the new twin produces a respectable peak power output of 62PS (61bhp) at 7400rpm, making this the most powerful Bonneville yet. Maximum torque is a substantial 60Nm (44ft-lbf), delivered at just 3500rpm. Perhaps the most important statistic is that 90 per cent of the engine's torque output is available from 2750rpm all the way to the rev limit.

The new engine is air-cooled, like the original, but differs in having twin overhead camshafts instead of the old model's pushrod valve operation. A discreet, frame-mounted oil cooler ensures consistent running temperatures for optimum reliability. Camshaft drive is by chain between the cylinders and incorporates an idler gear that allows the cylinder head to be kept very compact.

Our engine design team made the new powerplant as visually similar to the old one as possible. The oil drain tube at the front of the engine is designed to resemble a pushrod tube from the old unit. The five-speed gearbox is reversed, putting the final drive chain on the right instead of the left. This allows the traditional Triumph twin layout of small triangular engine cover on the right and larger clutch case on the left.

The engine's bottom end was made as compact as possible while incorporating features including the twin balancer shafts, which were necessary to reduce high-speed vibration to acceptable levels. The balancers were tuned to ensure that the solidly-mounted Bonneville motor has much of the feel of a traditional 360-degree Triumph twin, and is not over-smooth.

Naturally the new bike follows Bonneville tradition in having twin carburetors. These 36mm units differ from their predecessors by incorporating such modern touches as a throttle position sensor and electric heaters (to prevent icing). As well as crisp throttle response, a feature of the Bonneville engine is its very good fuel economy.

The exhaust system also combines tradition with modernity. "Peashooter" silencers faithfully follow the look of the originals. Yet this Bonneville's exhaust features a secondary air injection system to reduce emissions, and incorporates a catalytic converter for some markets.

Chassis
The key challenge facing the Bonneville's chassis team was to provide modern handling and steering characteristics using a very traditional layout. In particular, the chassis brief called for light, easy steering that would make the bike agile around town, plus a sporty feel and excellent high-speed stability.

Although the basic layout of the tubular steel cradle frame is simple, the design was realized using sophisticated finite element analysis to ensure maximum strength with minimum weight. Similar methods were used in the creation of the box-section steel swing-arm, which pivots through the crankcases.

Our design team achieved excellent results by using very similar geometry to the late-Sixties Bonneville, including a 19-inch front wheel and a 29-degree steering angle. Partly due to the twin's low center of gravity, the bike is very maneuverable without compromising stability.

Suspension is tuned to give a sporty feel, yet ride comfort has not been overlooked as it was felt that the Bonneville would be used in a wide variety of roles. The Bonneville's seat is well padded yet also notably low, at 775mm (30.5in), enhancing the bike's appeal to riders of all sizes.

The wheels combine wire-spoke design with 19in front, 17in rear diameters. They hold modern tires, whose grip can be fully exploited thanks to the Bonneville's generous cornering clearance. Brakes were another area where tradition was not allowed to compromise function. Single discs at front and rear, each with twin-piston caliper, give reliable and powerful stopping.

Style was always a key element of the Bonneville's appeal and that is as true of the new bike as the old. Features such as the classical Triumph tank badge look as striking now as they ever did. The redesigned speedometer and switchgear add elegance and functionality. Paintwork and chrome, applied in-house at our Hinckley factory, are deep and thick. The new Scarlet Red paint option, coupled with Silver, matches almost exactly the popular Hi-Fi Scarlet shade of the late Sixties, with Forest Green and Silver available as an eye-catching alternative. As in the old days, the gold pin-stripes are applied by the steady hands of Triumph workers.  In this as in so many other respects, tradition lives on in the new Bonneville.

DEVELOPMENT TIMETABLE

April 1997: Project begins with meetings to discuss viability of a twin-cylinder model.
Summer 1997: Concept agreed; chassis and engine design teams begin work.
August 1998: First styling review of full-scale three-dimensional model.  Input from sales and marketing as well as engineering departments. 
November 1998: Second major review to assess changes made in response to earlier feedback.
December 1998: Prototype engine runs on test bench for the first time.
March 1999: Engine is run in prototype chassis for the first time; full-scale testing starts.
July 1999: First six development bikes are built; four are mainly used for engine testing, two for chassis work.
September 1999: Final review by sales and marketing teams, to confirm production model's styling and specification.
July 2000: Final testing is completed.
September 2000: Bonneville launched at Intermot, Munich

TRIUMPH ACCESSORIES

2001 TRIUMPH BONNEVILLE (Specifications)

ENGINE

Type

Air-cooled,  DOHC, 360 parallel twin

Capacity

790cc

Bore/Stroke

86 x 68mm

Compression Ratio

9.2:1

Fuel System

Twin carburetors, with throttle position sensor and electric carburetor heaters

Ignition

Digital - inductive type

TRANSMISSION

 

Primary Drive

Gear

Final Drive

X ring chain

Clutch

Wet, multi-plate

Gearbox

5-speed

CHASSIS

Frame

Tubular steel cradle

Swingarm

Twin sided, tubular steel

Wheels: Front
Rear  

Spoke, 19 x 2.5in
Spoke, 17 x 3.5in

Tires: Front
Rear

100/90 19
130/80 17

Suspension: Front
Rear

41mm forks
Chromed spring twin shocks with adjustable preload

Brakes: Front
Rear

Single 310mm disc, 2 piston caliper
Single 255mm disc, 2 piston caliper

DIMENSIONS

Length

2250mm (88.6in)

Width

860mm (33.8in)

Height

1105mm (43.5in)

Seat Height

775mm (30.5in)

Wheelbase

1493mm (58.8in)

Rake / Trail

29o /117mm

Weight (Dry)

205kg (451lb)

Fuel Tank Capacity

16 liters (4.3 gal US)

PERFORMANCE

(measured to DIN 70020)

Maximum Power

62PS (61bhp) at 7,400 rpm

Maximum Torque

60Nm (44.3 ft-lb) at 3,500 rpm

MSRP (USA)

$6,999

BONNEVILLE HISTORY
The Bonneville was first produced in 1959, and rapidly became established as Triumph's most famous model. But in contrast to the three-year development period of its modern namesake, the original 650cc T120 Bonneville was created so hastily that there was no time to include it in Triumph's 1959 catalogue.

Essentially, the original T120 Bonneville was a high-performance, twin-carburetor version of Triumph's existing T110 Tiger. Performance minded riders had already been able to fit the Tiger and Trophy models with a twin-carburetor conversion, so it was a natural step for the factory to produce an official model incorporating this feature.

Even so, the Bonneville's birth was by no means a formality. The model was produced largely at the request of Triumph's agents in America, the firm's largest market in the late 1950s, where enthusiasts had been demanding extra performance. Triumph boss Edward Turner eventually agreed and named the new bike Bonneville after the scene of Johnny Allen's record-breaking exploits.

Triumph billed the new, 46bhp Bonneville as "The Best Motorcycle in the World" in its 1959 promotional material. "The Bonneville 120 offers the highest performance available today from a standard production motorcycle," the brochure continued. "This is the motorcycle for the really knowledgeable enthusiast who can appreciate and use the power provided.".

The initial T120 Bonneville's headlamp nacelle and heavy mudguards were dropped for 1960, to give a sportier look, and the frame was also revised. Although the T120 could not quite manage the 120mph (193km/h) top speed that its name suggested, it was good for over 110mph (177km/h). That performance, combined with attractive styling, light weight and good handling, was the key to the Bonneville's success.

Numerous changes and updates were made over the years, notably in 1963 when the Bonneville gained a "unit-construction" engine and gearbox, as well as another new frame. Ten years later the engine was enlarged, briefly to 725cc and then to 744cc, to produce the T140 Bonneville. But 1973 was a troubled time at Triumph, for it was in this year that workers took over the Meriden factory amid rumors that it was to be closed.

T140s were built by the Meriden workers co-operative from 1975, and the Bonneville continued in production into the 1980s. Variants during that period included the Executive Bonneville, with fairing, top-box and panniers; and the eight-valve TSS. Bonnevilles were the last bikes to be

built by Triumph before the Meriden factory closed in 1983. Even then the Bonnie refused to die. Small numbers were built under license by LF Harris of Newton Abbot, Devon, between 1985 and '88.

TRIUMPH'S BONNEVILLE CONNECTION
The Bonneville gained its name due to the Triumph-mounted achievements of Texan racer Johnny Allen on the Bonneville Salt Flats in Utah. In September 1955, Allen had ridden to a two-way average speed of 193.3mph (311km/h) aboard the "Devil's Arrow" or "Texas Cee-gar" (cigar) - a methanol-fuelled,650cc twin-cylinder Triumph engine in a unique "streamliner" body shell.

Allen's speed was ratified as a record by the AMA (American Motorcycle Association) but not by the world authority the FIM, as no approved observers were present. After German firm NSU had beaten the record the following year, Allen and his team returned to Bonneville in September 1956 and went faster still, averaging 214.17mph (344km/h). The FIM eventually also refused to accept this, too, as a world record, but Triumph gained much publicity from the legal battle that followed.

After the Bonneville roadster had been named in recognition of Allen's records, other Triumph-powered machines went faster still on the Salt Flats. In 1962 Bill Johnson set a two-way average of 230.269mph (370.5km/h) over a measured mile, riding a 667cc streamliner whose design was based on the American X-15 rocket plane.

Four years later, Detroit-based Triumph dealer Bob Leppan raised the record to 245.66mph (395.3km/h), aboard Gyronaut X-1, powered by two 650cc Triumph engines. For the next few years, Triumph fitted T120R Bonneville roadsters with stickers proclaiming: "World's Fastest Motorcycle".

Over the years the Bonneville was also raced very successfully all over the world, notably in the Isle of Man. John Hartle won the first Production TT on a Bonnie in 1967; two years later, Malcolm Uphill set the first 100mph (160.9km/h) lap of the Island en route to another victory. Bonnevilles also won the prestigious Thruxton 500-mile (804.5km) race four times in the Sixties, with riders including Ray Pickrell, Phil Read and factory tester Percy Tait.

One of the Bonneville's most spectacular appearances came in 1968, when stunt star Evel Knievel used a Bonneville TT Special for his infamous attempt to jump over the fountain at Caesar's Palace casino in Las Vegas. Knievel broke many bones after losing control on landing.

The Bonneville fared better in the same year when Clint Eastwood rode one through New York's Central Park in the movie Coogan's Bluff. Other movie appearances followed, and more than a decade later the Bonneville's lasting appeal was highlighted when a T140 Bonnie co-starred with Richard Gere in An Officer and a Gentleman.

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