If you want to be pedantic about it, art deco bikes are a contradiction in terms; while their smooth, flowing lines, bold, geometric trim and all-enveloping coachwork are intended to look as if they were styled in the 1930s, such bikes could not have been built 80 years ago.

Real 1930s bikes had no styling to speak of and wore all their engineering on the outside; and that’s probably why Harley-Davidson, the archetypal retro-cycle company, has never built a full-on California Cruiser.

Several Japanese makers have, however - and this one, the Yamaha XV1900A Roadliner, in our opinion best captures the look and feel of a time when America was just finding itself again after the twin disasters of prohibition and the depression, and the open road really was open.

True to the tradition of the time, Yamaha started with a really, really big V-twin engine, distinctly undersquare for maximum bottom-end torque at 100 x 118mm bore and stroke, giving it a monumental 1854cc.

Overhead camshafts would have made the engine too tall, so they went back to a vintage pushrod layout to reduce the height of the cylinder heads, brought up to date with four valves per cylinder, dual spark plugs and electronic fuel-injection via a 43mm, twin-bore downdraught throttle body.

A CERTAIN AMOUNT OF THUMP

Dual balance shafts, one on either side of the engine, keep both primary vibration and the inescapable V-twin rocking couple under control - or almost. Bikemakers have learned that a big twin needs a certain amount of thump to impart the right feel, so the Roadliner lets you know when it’s working properly, distinctly but not unpleasantly.

That thump is conveyed to the back wheel via a surprisingly slick five-speed gearbox and snatch-free final drive, to create a civilised prime mover that’s rated for 66.4kW at 4750rpm and a tar-wrinkling 155.1Nm at only 2500.

Given that the Roadliner weighs in at 347kg ready to roll and has all the aerodynamic finesse of a 1934 Packard, it doesn’t so much accelerate as gather momentum with almost complete disregard for the laws of physics.

Four clutchless upshifts in rapid-fire succession will get you up to 140km/h in about as much time as it takes you to read this sentence, after which you hold on to the wide, wide ‘bars like grim death for what seems like forever before the bike tops out at an indicated 202km/h, 400rpm on the wrong side of the red line at 5000, pulling a true 195km/h, which translates to a speedometer error of only 3.5 percent.

Once you’ve done that for the record, you back off to a relaxed cruise and, when you look down at the instruments, laid out on the top of the 16-litre fuel tank like the face of a 1930s radio, you discover you’re rumbling along at just under 3000rpm with the speedo needle pointing straight up at 110km/h, which just happens to be the speed limit on open roads across most of Europe, Australia and the United States.

Is Yamaha trying to tell us something?

Certainly, the Roadliner is as comfortable as a favourite armchair at that speed, soaking up the kilometres as if it could go on all day, which is where its tank capacity – only 16 litres – comes into question. Average fuel consumption, however, works out to just over seven litres per 100km, which gives it a range comfortably in excess of 200km, or about two hour’s riding at cruising speed.

This is not a chopper, so it has decent-sized rubber at both ends (130/70-18 in front, 190/60-17 at the rear) and is stable and predictable at any speed, with accurate if slightly ponderous steering, and cornering limited only by its truck-like 1715mm wheelbase and low-slung footboards.

Any 347kg motorcycle needs good brakes, and the Roadliner’s are beyond reproach, with four-piston Sumitomo monobloc callipers on dual 298mm discs in front and a low-tech but effective single-piston set-up at the rear. The bike was also reassuringly stable under even hard braking.

The suspension, unfortunately, is less successful. The conventional 46mm front end is soggy under pressure, using up most of its 130mm travel on the brakes, while the monoshock rear, limited to only 110mm of travel (and it feels like less) is stiff and bouncy in action, causing some longitudinal pitching, yet prone to bottoming out on poor surfaces.

This bike is not a commuter; the drivetrain is snatch-free down to walking pace but the bike is less than perfectly stable at that speed and, at an arm-stretching 1100mm across the handlebars, it is too wide to cut through the gridlock.

VERDICT

As its name suggests, it is most at home on the open road, where its effortless power delivery and relaxed seating position make it one of the few cruisers that’s really worthy of the name.

The long, low swoopy styling and superb detail work make it by far the prettiest machine in its class, while fit and finish are worthy of its status as the flagship of Yamaha’s Star range. But the Roadliner is more than the sum of its styling - you’ll want to ride it even when nobody can see you.

Price: R149 995.

Bike from: Helderberg Yamaha, Cape Town.

SPECIFICATIONS

Engine: 1854cc air-cooled four-stroke V-twin.

Bore x stroke: 100x118mm.

Compression ratio: 9.5:1.

Valvegear: Pushrod with four overhead valves per cylinder.

Power: 66.4kW at 4750rpm.

Torque: 155.1 Nm at 2500rpm.

Induction: Digital electronic fuel-injection with 43mm twin-bore downdraught throttle body and throttle position sensor.

Ignition: Digital TCI electronic.

Starting: Electric.

Clutch: Hydraulically actuated multiplate wet clutch.

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

Front Suspension: 46mm conventional cartridge forks adjustable for preload.

Rear Suspension: Link-type monoshock adjustable for preload.

Front brakes: Dual 298mm discs with Sumitomo four-pot opposed-piston monobloc callipers.

Rear brake: 320mm petal disc with underslung single-piston floating calliper.

Front tyre: 130/70 - 18 tubeless.

Rear tyre: 190/60 - 17 tubeless.

Wheelbase: 1715mm.

Seat height: 705mm.

Kerb weight: 347kg.

Fuel tank: 16 litres.

Top speed (measured): 195km/h.

Fuel consumption (measured): 7.06 litres per 100km.

Price: R149 995.

Bike from: Helderberg Yamaha, Cape Town.