The look, the layout and the performance of the 650cc XS-1 that Yamaha launched on the American market in 1969 were all familiar to riders who had grown up with British parallel twins. But this bike had one big difference, as the name and the tuning fork logo on its fuel tank made clear. The XS-1 was built by Yamaha of Japan, The last area of Britain's two-wheeled domination was about to be lost.

By 1969, Yamaha was already establishing a reputation for high performance, through its smaller two-strokes, on road and track. Factory racing star Phil Read had won both 250 and 125cc world championships in the previous season. But until the XS-1, Yamaha had never built a four-stroke roadster - let alone a 650cc parallel twin that was so obviously aimed at the British opposition.

And which scored a direct hit, too.

For although many riders questioned the wisdom of taking on the likes of Triumph's Bonneville and BSA's Lightning with such a similar bike, those doubts were rapidlyblown away.

The XS-1 - and particularly its descendants the XS-2 and XS650, for the original model was promptly updated - soon became strong sellers in the important American market, firmly establishing Yamaha as a manufacturer of large- capacity bikes.

The 654cc XS-1 engine followed the British opposition in its use of a 360-degree crankshaft, and even its 75 x 74mm bore and stroke dimensions were identical to those of the Lightning.

But the Japanese bike also had plenty of mechanical differences, notably its use of horizontally split crankcases. Instead of pushrods, its valves were operated by a single overhead camshaft, driven by a central chain. Peak output was a competitive 53bhp at 7000rpm.

The motor lived in a typical twin-downtube steel frame, which held front forks whose rubber gaiters concealed external springs. Brakes were drums at both ends, with a powerful twin-leading- shoe unit up front. Designed mainly for the American market, the XS-1 looked lean and sporty despite high, wide bars - and despite the fact that it was heavier, at 4291b (195kg) with half a tank of fuel, than a genuine Bonneville. 


Pulling power   

That weight and the engine's fairly soft state of tune did not prevent the twin from having lively acceleration. It pulled cleanly from below 2000rpm in top gear, had plenty of mid-range punch, and was good for a top speed of 105mph (169km/h). Although the engine vibrated in typical parallel twin fashion at around 4000rpm, it smoothed as it approached the 7500rpm redline. And the twin was strong enough to be revved hard, even when tuned for flat-track racing.

The Yamaha 650 chassis was less impressive.

The frame and swingarm lacked rigidity, and combined with the under-damped suspension to result in a frequent weave at high speed, and a choppy ride on bumpy roads. The Japanese bike was fine at a gentle pace, and had to be ridden really hard before it began to misbehave seriously. But its handling, unlike its engine, was no match for the better developed British opposition.

Cycle World was impressed, nevertheless, reporting that the XS-1 'supplied all the ingredients required to please the Big Twin fancier in an up-to- date, beautifully styled package. It looks good, rides good, stays clean and shows few of the faults one would expect in a first-year model.' Those assets plus the Yamaha's reliability and competitive price helped make it a hit in the States.

Although it had its faults, the XS-1 was a fine first attempt that paved the way for its XS-2 and XS650 successors to establish themselves as some of the best-selling bikes of the 1970s. 

YAMAHA 650  price's 2014

MINT                   $6,000    $10,000     £4.500    £6.500

GOOD                   $4,950                           £3,500
FAIR                      $2,500                          £2.000
PROJECT              $1,000                          £650

No comments:

Post a Comment