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Suzuki GT 550A - B

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Make Model

Suzuki GT550A - B

Year

1976 - 1977

Engine

Two stroke, transverse three cylinder

Capacity

543 cc / 33.1 cu in
Bore x Stroke 61 x 62 mm
Compression Ratio 6.8:1

Induction

3 x 28mm Mikuni carburetors

Ignition

Battery/coil with contact breakers

IBattery

12V, 11Ah

Starting

Electric and kick

Max Power

40 kW / 53 hp @ 7500 rpm

Max Torque

53 Nm / 39.7 lb-ft @ 6000 rpm
Clutch Multi-disc wet clutch

Transmission

5 Speed, constant mesh

Final Drive

Chain, endless 530
Frame Welded mild steel tubing

Front Suspension

Telehydraulic fork

Rear Suspension

Dual shocks swinging fork preload adjustable

Front Brakes

Single 290 mm hydraulically operated disk

Rear Brakes

Drum

Front Tyre

3.25-19

Rear Tyre

4.00-18

Dimensions

Length: 2195 mm / 86.4 in
Width:     815 mm / 32.1 in
Height:  1160 mm / 45.7 in

Wheelbase

1465 mm / 57.7 in

Ground Clearance

145 mm / 5.7 in

Dry Weight

186.8 kg / 412 lbs
Wet Weight 211 kg / 465 lbs

Fuel Capacity 

12.5 Litres / 3.3 US gal / 2.7 Imp gal
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I'll never forget my first ride on a Suzuki GT550A, and not just because it was the first nearly new motorbike I'd ever been on. It was also one of the most exciting and terrifying experiences of my life. Not that I was actually riding the air-cooled triple back in 1976, you understand. I was merely the passenger, on the briefest of rides across a large car-park, aboard the Suzuki owned by our school's resident rich kid and motorbike fanatic.

This was one lucky schoolboy—the recipient of a screaming 50cc Yamaha FS1-E from his parents for his 16th birthday, a Suzuki GT185 for his 17th, and a GT550 to celebrate his 18th. He was posing with his gleaming triple outside the local disco one evening, casually dropping comments such as "ton-plus top speed" into the conversation with this easily impressed would-be motorcyclist. Then he said I could have a quick go on the back if I liked.

Seconds later I was perched on the pillion seat, the burble from the trio of two-stroke cylinders just about drowning out the boom-boom-boom of my heartbeat. It was the gentle way that he pulled away that threw me. I relaxed my grip on the grab-rail just as he notched it into second, grabbed a handful of throttle, and sent the Suzuki screaming forward with a force that sent my legs in the air and, for several agonizing seconds, made me think I was about to be left in a heap on the ground.

Thankfully he had to back off moments later; I just stayed on, and naturally didn't admit afterwards that I'd been the slightest bit worried. I was certainly changed forever, though. It was probably during those few moments that I was incurably addicted to big, fast, hard-accelerating motorcycles.

And before you start sneering, back in 1976 that's exactly what the Suzuki GT550A was. The air-cooled two-stroke triple might not have had the cubes or the outright performance of Suzuki's water-cooled GT750-three, let alone the likes of Kawasaki's H2 750. But the 550's lively acceleration and genuine 100 mph-plus (160 km/h-plus) top speed meant that it was outclassed only by the fastest of superbikes.

The GT550, known as the Indy in the States, had been around since 1972, gaining a disc front brake, a few horsepower, and a few other improvements along the way. Similar in looks and layout to the GT380 triple, it was notable for employing Suzuki's Ram Air System—which referred to the simple piece of bent metal that helped direct a cooling breeze over the cylinder head. Breathing in through a trio of 28 mm Mikuni carburetors and out through a bulky four-pipe exhaust system, the 543cc motor produced 53 BHP at 7500 rpm.

A typical twin-cradle steel frame held nonadjustable forks and twin shocks with five-way preload adjustment. Rounded styling, a thick dual-seat and weight of 205 kg—pretty heavy by middleweight standards—suggested a practical all-rounder in the style of the range-topping GT750.

Suzuki's Ram Air System was nothing more elaborate than a piece of curved metal that directed cooling air onto the two-stroke triple's cylinder head. The 543cc unit produced a respectable 53 BHP and was torquey and reliable, if thirsty. Its three-into-four exhaust system helped keep noise to reasonable levels, at the expense of extra weight. The nicely restored GT550 felt quite light and sporty as I hit the button, prodded it into gear, and set off.

The engine took no time at all to confirm just how torquey and relaxed it was. The Suzuki pulled away easily, and its pleasantly crisp midrange performance was well matched to the fairly relaxed pace encouraged by the wide, slightly raised handlebars. When I short-shifted through the slick five-speed gearbox, the GT550 responded with a steady stream of power.

At most revs the rubber-mounted triple felt reasonably smooth, too, though from about 5000 RPM it began to buzz through its bars and footpegs, before smoothing out again toward the red-line. Top speed was close to 110 mph (175 km/h). But on this windy day it wouldn't pull above an indicated 80 mph (130 km/h) in top, and only screamed to 95 mph (153 km/h) when I changed down to fourth to get the revs up nearer the 7500 RPM red-line.

That blustery wind also brought out the worst in the Suzuki's chassis, triggering a gentle wobble that began at about 80 mph (130 km/h) and refused to go away until I slowed down. But the bike never felt worrying, and its handling at slower speeds was pretty good, let down only by the overfirm suspension.

On smooth roads the GT could be cornered pretty rapidly, even so, aided by its narrow but respectably grippy Pirellis. Those wide bars gave enough leverage to allow fairly quick direction changes, despite the old-fashioned steering geometry and 19-inch front wheel. Brakes were reasonably good, too, the Suzuki's single front disc slowing the bike hard with help from the cable-operated rear drum.

That all helped make the GT550 a deceptively rapid bike, and it was practical in some ways, too. Switchgear and instrumentation (including a digital gear indicator) were competent, the seat comfortable, and the solid grab-rail gave most pillions, at least, a chance of enjoying the ride. But the headlamp was feeble, and the motor so thirsty that the small fuel tank gave a range of only about 100 miles (160 km).

That and the harsh ride handicapped the GT550's touring ability and help explain why the bike was never as popular as Suzuki must have hoped. By 1976 the opposition from four-strokes such as Honda's new CB550-four was strong, while the triple had improved little in several years—partly because Suzuki knew that time was running out for smoky, thirsty two-strokes.

A year later, in 1977, Suzuki entered the four-stroke middleweight market with the GS550-four, leaving the two-stroke on the sidelines. Although the GS was more expensive and no faster than the GT, it looked and handled better, and was more economical, more environmentally friendly, and clearly the machine of the future. The GT550 triple's days were numbered, but for me and plenty of others, it had provided some memorable moments.

From Bike, Nov. 1976

"Lack of rear suspension compliance must be one of the Suzuki's worst points, along with a poor riding position and inadequate fuel capacity. Best thing about the rubber-mounted motor is its vast acreage of usable power, spread from anything over three grand right up to the red-line.

Even five gears seem one too many on occasion, so smooth is the urgent surge of three cylinders. But just as you're about to sail smoothly over the legal limit at 5000 RPM in top, an ugly patch of vibration shows up.

Its frame may look just like a collection of tubes holding two wheels apart, tacked together with aesthetically repulsive gusseting, but it handles despite the rear springs' attempts to prevent it holding a line. It may not wheelie its way into your affections, but a standing quarter time in the 13-second bracket from 543cc ain't to be sniffed at."

Source Superbike of the seventies