Señor Bulto had a simple plan when he started up the Bultaco brand in 1958: build great competition motorcycles. And he did. In the 1960s his two-stroke singles took the checkered flag in everything from motocross to trials to roadracing. The bikes were strong, light and dependable, and this was when most of the racing was done by individuals, rather than factory-supported riders.
He also liked evocative names. The first Bultaco was the Tralla, or Whip. Then there was the Metralla, or Shrapnel, and the Pursang—Pure Blood. The Matador was self-explanatory, denoting bull-fighting glory. The Sherpa celebrated the conquering of Mount Everest. And then the Alpina, honoring Europe’s largest mountain range, and the model we will talk about here.
Over the 25 years of Bultaco’s existence, 1958 to 1983, probably a hundred models appeared, ranging in size from the 50cc Chispa (Spark) to the 370cc Frontera (Frontier). Bulto loved racing, having been a successful competitor in his younger years, and what he liked to do was build a bike that could win races, and then turn out detuned versions for civilian use.
His engineers were also skillful at having one part fit several models, decreasing the costs of production. Bultacos were not inexpensive, and while they had a great racing background, they were competing with other European manufacturers and the coming onslaught of the Japanese.
Reliable production numbers are hard to come by, but one of the more successful models was the Alpina 250—which appeared in 1971, to be followed by 125, 175 and 350 versions. The first 250 Bultaco was a Sherpa, appearing in 1964, a trials and enduro motorcycle intended to win races rather than coddle the rider. It did take the European Trials Championship in 1968, and world titles after that.
Bulto was constantly upgrading his machines, making them even more competitive. The new Sherpa received a major do-over around 1970, and the projected Alpina was intended as the successor to the old Sherpa, being made a bit more manageable and rider friendly. The Alpina was advertised as a trials bike, but in truth was more of a trail-riding machine, great for plunking along dirt tracks. It was reliable, and capable of giving even a novice a pleasurable day of bashing the boonies. To make the Alpina more useful and friendly, the gas tank was enlarged to 2.6 gallons, with a longer saddle and rear footpegs so that a passenger could be carried along. And basic lights, of course.
The new model was essentially using the same frame as the Sherpa, with slightly different geometry. This was a steel affair, pretty unbreakable, with a single downtube (in an effort to keep the frame as light as possible) splitting into a full cradle going under the engine.
The Alpina weighed in at a very modest 217 curbside pounds (claimed), as opposed to an equivalent English 250 four-stroke single, which could run almost 300 pounds. The slow-turning engine of the British thumper was very useful in putting trials-type power to the rear wheel, until Bulto and his engineers figured out how to do roughly the same with a two-stroke, using heavier flywheels. They made sure the engine was properly balanced internally so as not to break the motor mounts, a not-unknown problem in those days. Also, a bracket ran from the cylinder head, secured by two head-bolts, up to the backbone tube of the frame just to ensure appropriate rigidity.
The Alpina’s 244cc piston-port engine had a wide bore of 72mm, a stroke of 60mm, and at 5,500 rpm was said to put out almost 25 useful horses. A chokeless 26mm Amal carburetor fed fuel mixture to the combustion chamber, where it was compressed 9:1, and the bike ran well on 87-octane gasoline. One complaint was the need to pre-mix the fuel, at a 50-to-1 ratio. The Japanese had done away with that little botheration on their two-strokes, while the British thumpers ran straight gas. Older two-stroke owners were quite content dealing with this minor fiddle, but the younger types found it rather irksome.
Ignition was by a Femsa magneto on the flywheel, which was used by many European two strokes, including the Spanish compatriots Ossa and Montesa and companies like Maico and Sachs. Kickstarter was on the left side, so those right-footers often stood beside the bike to start it. A primary chain ran back to a wet clutch and 5-speed transmission which had been borrowed from the Matador, a model intended for the International Six Days Trial, the tranny of which was a bit beefier than that on the Sherpa. The Matador’s gearing was more suitable for a trail bike, blipping along for miles at a reasonable speed, rather than climbing up a mountainside in first gear.
A steep Bultaco-built front fork gave 7 inches of travel, with Betor shock absorbers at the rear. Wheels were Akront aluminum, wearing a 2.75 x 20 tire at the front, 4.00 x 18 at the back. Drum brakes were adequate for the purpose of the Alpina. All this fit into a short wheelbase of 52.3 inches, with 11 inches of ground clearance—and the ability to dance around or over any obstacle.
A minor change to the engine was made in 1974, decreasing the displacement from 244cc to 237. This was done not for any technical reason, but to keep the model in line with other engines. Slightly heavier flywheels were added at the same time, increasing flexibility. Other small changes were made over the nine years of production, with the Alpina becoming a favored play bike for Americans as well as many Europeans.
Unfortunately the factory fell on hard times in 1979, and was briefly closed. When restarted in 1980, the Alpina was not in the lineup.
Source: http://ift.tt/1cvLdIj February 14, 2018 at 09:15PM