Here is an attractive little trail bike, built by Harley’s former Italian subsidiary, Aermacchi. Oddly, virtually nothing has been written about this model in the American moto-press. Your scribe has looked many places, and could not find a single road test. More than a dozen Harley histories are on my shelves, some of which never even mention the Italian connection, which went from 1960 to 1978. There is reasonable reportage on the four-stroke Sprint models, less on the two-stroke Rapido 125 and Baja 100, so I am making do with what we have.
Harley should be proud of the Italian connection, because it provided the company with four international GP racing victories when Italian road-racer Walter Villa won the 250 class in 1974, ’75 and ’76, doubling up in 1976 by winning the 350 class as well — riding a parallel-twin two-stroke built by Aermacchi with Harley-Davidson writ large on the fairing.
The name Aermacchi comes from combining the two words from the previous company, Aeronautica Macchi, with which Giulio Macchi began producing airplanes in 1912. However, being on the losing side in World War II, the company had to stop making airplanes and instead moved into basic transportation — the motorcycle. Early models used a four-stroke single from 175cc to 350cc with the cylinder lying forward, almost flat.
In 1960 Harley, aware of the popularity of bikes like Honda’s small OHC twins, looked at its own small bikes, a couple of rather antiquated 165cc two-strokes that had begun with the 125 Model S in 1948. Which was based on a German DKW bike, the designs for which had been given to the U.S. as part of war reparations. Now the Milwaukee suits tapped on the door of another WWII foe and cut a deal for half the company. In 1961 the first 250 models, called Wisconsins, arrived at dealers — shortly after which it was noted that this bike had nothing whatsoever to do with Wisconsin, and the name was quickly changed to Sprint.
In 1965 the first Italian-built two-stroke came into the country, a little 50cc model that the Harley dealers really objected to. Two years later that grew to 65cc, which did not help much, while the last of the DKW-based two-strokes vanished. Then the 125cc Rapido two-stroke came along in 1968, which was anything but rapid.
1969 was an interesting year for Harley, as an outfit called American Machine Foundry bought the motorcycle company. AMF was best known for selling golf carts and bowling equipment, and thought its sporting knowledge would work well with a motorcycle company. It did not. We won’t get into the Harley-Davidson snowmobile.
For 1970 the little Baja 100 two-stroke appeared, an off-road bike that appealed to quite a few riders. And it won its class in the 1971 Baja 1000 race. This was a serious effort by Harley to build a great desert racer and enduro machine, and they got a lot of help from the racers themselves. The engine was a Rapido cylinder sleeved down to 98cc. An automatic gas-oil mix was developed to simplify fueling.
Obviously AMF thought that this two-stroke connection was good, and bought the entire Aermacchi Company in 1974. Aermacchi could still pursue its European market, with Walter Villa’s racing, while the profits would go to Milwaukee. The following year was the last for the lone remaining four-stroke, a 250 Sprint.
And it was the first for the SXT-125, a well-designed trail bike that was meant to appeal to the rough-and-ready folk who had liked the Baja 100. The engineers at the Aermacchi plant in Varese built a slightly oversquare engine, with a 56mm bore, 50mm stroke, using piston-port induction. The cast aluminum cylinder liner had a chrome-plated bore, which was quite useful considering the rather serious 10.8:1 compression ratio, providing some 13 rear-wheel horsepower at a little over 7,000 rpm. Kickstart only.
An oil container under the gas tank held a little more than three pints; this had no sight window and the rider had to look carefully into the opening up by the steering head to see if more needed to be added. A Mikuni pump pushed the oil into the intake to mix it with the gas flowing through a 27mm Dell’Orto carburetor. Oil metering was controlled by the throttle, with one cable running to the pump, another to the carburetor.
Electrics were simple enough, with a flywheel-alternator charging a 12-volt battery, and easily adjusted points. Turn signals were mandatory. Up on the dash were two round instrument cases, one being the speedometer. The other, which did not hold a tachometer, served to house the ignition key and lights for high beam and ignition.
Gears took the power from the crankshaft to the wet clutch, then through a five-speed transmission with its own oil supply. The transmission sprocket had 14 teeth, the rear sprocket, 61. A useful primary starter allowed the bike to be kickstarted in gear after pulling in the clutch.
The frame used double downtubes, with a cradle running beneath the engine and serving as a sort of skid plate. A Ceriani fork did a good job up front, with Betor shocks at the back, adjustable for spring preload. Wheels were a 3.00 x 19 at the front, 3.50 x 18 at the back, both with five-inch, full-hub drum brakes. Wet weight was a respectable 240 pounds.
Seat height was almost 30 inches, with a saddle long enough to move about comfortably. No passenger footpegs. Good-looking machine, with an upswept muffler and 2.7-gallon gas tank. But dealers were not pushing them, and sales did not meet expectations. So what did AMF do? Sell the whole shebang in 1978 to an Italian company called Cagiva. And the “Cagiva HD SXT 125” became a bestseller in Europe.
P.S. Should any readers have information about this bike, please contact us at firstname.lastname@example.org.