The Tonti design was quite unusual - the engine was situated below the saddle and formed part of the rear suspension, scooter-style. Suspension was dual shockabsorbers rear, and Earles forks front. The two-stroke engine has a bore/stroke of 52x58mm giving 123cc, 6v Marelli electics, Dell'orto UA17 carburettor, 3 speed gearbox, 17" wheel.s
During 1954 the Ghibli 125 U was introduced, similar to the Monsone which remained in production. That year also include the Schiranna, a twin-cylinder model, and two motocarri; the Cavaliere 125 and the MacchiTre MB1.
Introduced at the Milan Show of November 1955, the Chimera was quite a sensation with its relatively powerful horizontal fourstroke engine, sleek enclosed bodywork, and monocross suspension - a system not seen on other production machines until decades later. The machine's designer, Alfredo Bianchi, already had a long list of credits for notable machines penned for Astoria and Parilla, and the success of this one was immediate. Production began in 1956 and continued until 1961.
The 1961 Model C Sprint was the first product imported to the United States as a result of the agreement between Aermacchi and Harley-Davidson.
A horizontal 250cc four-stroke OHV engine powered this lightweight. It has an alloy cylinder head with 9:1 compression ratio developing a claimed 18 horsepower at 7,500 rpm. It was fitted with a 4 speed gearbox with gearshift on the left, something of a trap for the American rider to get used to prior to the Japanese onslaught.
1963-1969, fewer than 2200 built.
The Aermacchi-HD 150cc scooter was announced at the Milan Show of 1963 in direct competition with the two major players in the scooter field, Lambretta and Vespa and was not marketed in the United States.
The scooter had conventional 3-speed shift on the handlebars and the two-stroke engine was fed by a Dell'Orto SH 1/18 carburettor. Electrics were 6 volts via flywheel magneto, and the 90 kg machine had 3.00 x 12 inch tyres front and rear.
This 48cc machine came as a moped, the 48NP (P for pedals) and without pedals, a no-ped, hence 48N with no P. (Yeah, right!)
The engine is 38x42mm, plain piston-port, CR 8.5:1, with 3 speeds actuated by a hand shift. The 48NP was built until 1965 with much of the production going to the Italian market, whilst the 48N continued on until 1972.
The M-50s two-stroke engine developed 2.5 horsepower from 50ccc, delivering power via a thre-speed gearbox. Gear shift was scooter-style via a cable from the handgrip. Built on Lake Varese in the Aermacchi factory this was Harley-Davidson's smallest ever motorcycle
The tiddler weighed 103 pounds, had a 1.6-gallon petrol tank, had reasonable fuel economy and sold for a mere for $225.00.
Around 9,000 M-50 models were produced in 1965.
Fitted with a 4-speed gearbox and the engine of the Azzurra, the model was built in small quantities for one year only.
A GT model also appeared with a 5 speed box. The Ala Blu GT 250-M remained in the product lineup until 1972, and in total somewhat more than 725 machines were manufactured.
The development of the 125cc Ala d'Oro began in 1966 with the prototype raced in 1967. It had a with a bore and stroke of 56x50mm and developed 10 horsepower more than its predecessor.
The already attractive machine was further developed through the 1968 season and the first production racers appeared on the dealers showroom floors in 1969.
207 Ala d'Oro 125s were produced.
Towards the end of 1966 Aermacchi began the development of a 125 two-stroke engine, and a year later the Alleta 125 was displayed at the Milan Show. It was marketed in 1968 as the Turismo 125 and was fitted with a conventional piston-port engine of 56x50mm running on premix, as did almost all two-strokes of the day.
The frame was very similar to that of the Zeffiretto S and the M50/M65S models, with changes made to the rear end of the larger capacity bike.
Production ceased in 1970 after some 560 units had left the factory. A scrambler model Aletta also appeared in 1968, and somewhat more than 600 of these were built. These models were followed, in 1972, by a De Luxe Aletta 125cc, production of which ended a year later. Total De Luxe models - 1014.
The Aletta was marketed in the United States as the Rapido, and numerous changes were made to its appearance for the very different American market. It was a very successful machine, and one of the models was particularly well recieved - the 125 R/C Trail. This machine continued to be produced after the company changed hands and was renamed AMF Harley-Davidson. The HD logo was no doubt a considerable bonus to the sales team.
For the US market the Aermacchi Zeffiretto Sport 48S was titled simply M50S, and mildly restyled with typically high American-style handlebars and the removal of the toolboxes. The following year the larger M65S replaced the 48, with almost identical appearance.
The M-65S continued in the catalogs until 1970 when the Leggero "Mini Cycle" appeared, with a foot-operated gear change rather than hand change. Distribution of this model ceased in 1971.
Based on the ML Rapido, the MSR was designed for off-road competition as befits its name. It was very much the same as the road-going SR-100, without lights, and the M in MSR is thought to have denoted Motocross.
Sold from 1970 to 1974, the machine had a 100cc two-stroke engine fed by a Dell'Orto MB-24A carburettor, and tyre sizes of 18" rear and 21" front.
The Bicycilindra first appeared at the Modena circuit with Renzo Pasolini aboard for tests. It was developed by Alfredo Bianchi, technical director, ably assisted by William Soncini. Based on the 125 racing engine, it was two top ends on a common crankcase in parallel twin configuration in 250cc and 350cc versions. The barells were of 175cc capacity giving a total volume of just under 350cc. Both Pasolini and Walter Villa had wins on these machines.
In all, Harley's initial foray into the burgeoning minibike market was a very attractive offering. It was upgraded the following year with a 90cc 4-speed model, termed the X-90.
The lightweight trailbike shared the specification of the MSR with a 100cc engine and Dell'Orto MB-24A carburettor, and tyre sizes of 18" rear and 21"
The engine was a 4 speed 90cc twostroke of 48x50mm and CR 1:9.22 with oil injection from a separate tank, the oil-pump being driven from the crankshaft.
The Z90 model was a larger machine, featuring a dual seat and lighting, using some electrical components common to the SS/SX models and the frame was similar to the SR100 Baja. This models was still available in some markets well into 1975.
Based on its predecssors the 125cc MLS and De Luxe, the Aermacchi HD TX125 had revamped and stronger frame with a steel sump guard in place below the engine on the off-road model. Fitted with indicators for the US market, it had a 5 speed engine. The model suffered some critisism for gearbox problems and also body finish, and around 10,000 units were produced.
The machine offered a robust electrical system by ND with electric starting and a fair chunk of battery to run it, all housed in a new frame. There was a similar model available for off-road work, the SX-350.
Developed from the SX125 of 1974, it runs the same frame as the '75 SX175 and an upgraded 125cc engine, with compression increased to 10.8:1 (very high for a twostroke), 12hp (up from less than 10) and a larger Dell'Orto of 27mm choke.