Yamaha V-Max

Yamaha's V-Max is designed to excel in the acceleration field. Its top speed of around 135mph is not as high as it might be, given a monstrous V4 engine with a power output of 145hp, and compared with race-replica models. What is sensational is how quickly it gets to that speed. Acceleration is the V-Max's reason for being, helped by the fat rear tyre like that of a drag bike and gearing to match.

Launched in 1984, the V-Max became at once the ultimate hot rod, the fastest-accelerating road bike ever, sizzling through the standing quarter mile in not quite ten seconds. Ten years before, only specialized dragsters could accelerate like that.

The basis of this factory hot rod was the big V4 engine from Yamaha's Venture tourer - a veritable river-barge of a bike, festooned with fairings and luggage gear. All that went, and the V-Max was left behind, spare but still monstrous, its styling dominated by the massive engine with two giant air-scoops for the four down-draught carburettors where you would expect to see the fuel tank. The V-Max, like the Venture, has a low-slung tank beneath the seat, with the fuel pumped up to the four greedy carburetor throats.

A vestigial pillion seat completed the spartan look, while the back tyre behind it was of unprecedented width: a 150/90 x 15 monster.

The engine was revitalized to release more of its fire-breathing potential, with the output rising from 90bhp in Venture trim to a massive 145hp as the V-Max. The factory hop-up job was thorough, including a stronger crankshaft, lightened pistons with a 10.5:1 compression ratio, bigger valves, and high-lift double overhead camshafts. Yamaha also introduced a novel system of automatic butterfly valves linking the inlet tracts below the carburettors, which smoothed out the power delivery right across the rev range. The V-Max retained the shaft drive of the touring bike, freeing the owner from the burden of replacing shattered rear chains and the hard-worked rear tyre.In a straight line, there is nothing to touch the V-Max. The way it hunkers down and takes off leaves all its rivals gasping. If its handling on a twisty road is a bit twitchy, it makes up so much ground Jberween the bends that it hardly matters.

On a long high-speed run, the rider - sitting upright and holding onto high and wide handlebars - feels like a parachute as the wind catches the chest. This more or less confined the V-Max's usefulness to the USA, where low speed limits favour fast acceleration at the expense of top speed. Europe did not see the V-Max, except as a spectre of the imagination.