When Triumph designer Edward Turner invented the parallel twin in 1938, he made both pistons rise and fall together, partly because it only needed one ignition system and partly because, by firing them alternately, he sought to achieve perfect primary balance.

American bikers, however - and drivers, for that matter - prefer the sound of a V engine, which has two pistons firing in quick succession, followed by a long gap before the next firing stroke, creating a characteristic deep-throated rumble.

At about the same time Australian engine genius Phil Irving theorised that a parallel twin with its crankpins spaced 76 degrees apart would not only have perfect primary and secondary balance but would also run (and sound!) like a V-twin.

In the event he and Phillip Vincent went ahead and built a V-twin anyway (the Vincent Rapide, which became the iconic Black Shadow, revered to this day as the original superbike) and it wasn’t until 1996 that Yamaha put the idea into practice on the TRX850 café racer, spacing the pistons at 270 degrees to give it an even more distinctive V-twin sound.

And when Triumph adapted their 790cc Bonneville for the American market in 2003, they did exactly the same, giving this very British twin a distinctive American accent, complete with a good natured pop-and-crackle on the overrun that sounds like a turbocharged coffee percolator. They called it the Speedmaster, a name used in the mid-1960s for American-spec T120R twins.

In 2005 the engine was bored out to 865cc - the same as the Thruxton - and two years later the entire parallel-twin range went to fuel-injection to keep them on the right side of the Pollution Police.

DUMMY CARBS

Or did they? The first thing I noticed about the 2013 Triumph Speedmaster was a pair of Keihin CVK carburettors, complete with butterfly throttles, choke and idle adjustment knobs - all of which actually work! - as well as individual serial numbers.

But when I started the bike I heard the unmistakeable whine of an electric fuel-injection pump. Yes, Cyril, the Keihins are dummies - there’s no fuel in the float bowls and where the slides should be there are a pair of multipoint sequential fuel-injectors with secondary air-injectors.

Why Hinckley should go to the trouble of packaging the injection system inside a pair of carbs which are in any case wrong for the period the bike is intended to evoke is beyond me, although I suppose older riders may find the adjustments reassuring.

What’s more important from a riding point of view is that they don’t feel like fuel-injectors; Triumph have got the damping exactly right and the bike feels as if it’s running on a perfectly set-up pair of Amal carbs - to the point that its throttle response becomes a little jerky just before the fuel light comes on.

ELECTRONIC LIMITER

The softly-tuned Speedmaster is rated for 45kW at 6800rpm and a respectable 72Nm at 3300rpm. It seems to have a slight flat spot off idle, so it’s quite easy to stall, but keep the revs above 2500rpm and this 250kg cruiser will get off the line and up to 140km/h quickly and without fuss.

After that you have to work for everything you get - and I was surprised to discover that the Speedmaster has an electronic limiter. Whether at 5250rpm in top or 6800 in fourth, the test bike refused to go over an indicated 158km/h - a true 155, according to Mr Garmin and his friends in the sky, for a speedometer error of less than two percent.

But that’s not what this bike is about and, in fact, the only time I hit the limiter was on our top-end runs. The Speedmaster does its best work between 100 and 140km/h and that’s mostly where we rode it, enjoying the dragging boot-heels and strong torque out of corners that always makes a cruiser feel like it’s running harder than it really is, the instant acceleration that makes commuting cool even in fairly heavy traffic and the laid-back seating position that makes long, lazy summer afternoons in the country so much more fun than mowing the lawn.

SLICK-SHIFTING TRANSMISSION

Thanks to the balance shaft the only vibration you feel is a subdued and not unpleasant thrumming through pegs and seat, while the five-speed gearbox reinforces Hinckley’s reputation for slick-shifting transmissions with some of the neatest upshifts - with or without clutch - I’ve ever enjoyed, although downshifts are apt to produce a clunk that is as much felt through the frame as heard.

This gets worse towards the end of a long ride, and a scorch-mark on the inside of my right ankle is evidence that, despite the presence of a handsome oil-cooler between the frame down-tubes, the Speedmaster runs very hot in a South African summer. Sticking to the letter of the service manual and using the best-quality oil you can get is advised.

The dual KYB rear shock absorbers, adjustable for preload, offer only 96mm of travel, so rear suspension action is on the harsh side of firm. Every inequality on our bumpy test section is inexorably transferred to the rider’s spine, although the broad, deeply padded seat takes most of the sting out of it.

The narrow 19” front wheel and 41mm KYB forks (no adjustment there) modulate front-wheel movement in a much more civilised manner, and I have no hesitation in ascribing a very slight ‘hippy hippy shake’ on long sweeps to the rear end.

NATURAL SEATING POSITION

For 2013 Triumph have brought the handlebars (straight ‘drag’ bars on neat curved riders) more sharply back towards the rider and moved the footpegs further aft and a little up, for a more relaxed - indeed, more natural - seating position and better all-round control.

The brakes - a single disc with floating calliper at each end - are straight out of Nissin’s 1970s parts bin and, as such, a little prone to fade when punished, but more than adequate when used together, which is in any case always advisable when dealing with a long (1606mm) wheelbase and stretched-out steering angle.

Seat height is a tail-dragging 690mm, which puts the neat little speedometer on its long, wiggly sheet-metal bracket almost in your line of sight, while the idiot lights (sorry, warning icons) and tiny rev-counter are housed in a chromed fascia on top of the tank. This is not generally a hassle, although it can be a nuisance when the bike is really hot and neutral becomes a little elusive.

VERDICT

The Speedmaster will inevitably be compared with the 883cc Harley-Davidson Sportster, against which it actually comes off rather well. Fit and finish are nearly as good, handling and brakes are on a par and the up-to date 270-degree parallel-twin engine is a much more complete package than Milwaukee’s 1957-vintage long-stroke V-twin lump.

Triumph’s Britbike with a redneck accent is a civilised way to cruise.

Price: R89 500.

Bike from: Mike Hopkins Motorcycles, Cape Town.

SPECIFICATIONS

Engine: 865cc air and oil-cooled 270-degree parallel four-stroke twin.

Bore x stroke: 90 x 68mm.

Valvegear: DOHC with four overhead valves per cylinder.

Power: 45kW at 6800rpm.

Torque: 72Nm at 3300rpm.

Induction: Multipoint sequential electronic fuel-injection with secondary air injection.

Ignition: Digital electronic.

Starting: Electric.

Clutch: Cable-operated multiplate wet clutch.

Transmission: Five-speed constant-mesh gearbox with final drive by chain.

Front Suspension: 41mm conventional KYB cartridge forks, non-adjustable.

Rear Suspension: Dual KYB chromed spring hydraulic dampers, adjustable for preload.

Front brakes: 310mm disc with Nissin twin-piston floating calliper.

Rear brake: 285mm disc with twin-piston floating calliper.

Front tyre: 100/90 - 19 tubeless.

Rear tyre: 170/80 - 15 tubeless.

Wheelbase: 1606mm.

Seat height: 690mm.

Kerb weight: 250kg.

Fuel tank: 19.3 litres.

Top speed (measured): 155km/h (electronically limited).

Fuel consumption (measured): 6.14 litres per 100km

Price: R89 500.

Bike from: Mike Hopkins Motorcycles, Cape Town.