Gilera 125 & 150 & 175 Extra Rossa

After the Second World War , there was a great diffusion of the two motorized wheels (either in the form of a micromotor or as a scooter or motorcycle), which helped to solve the mobility problems of the population. Responses to this need were almost immediate by the Italian Motorcycle Houses, both for those already on the market in the postwar period ( Bianchi , Moto Guzzi ) and for that myriad of builders who appeared after the conflict as Ducati , Innocenti , Mondial , Moto Morini , Parilla and Piaggio , as well as a huge array of assemblers, many of whom were "inspired" by the DKW RT 125 , capable of twisting "125" two-stroke models, from the costs associated with the immediate economic constraints After war .
At the end of the war, Gilera had preferred to introduce Neptune and Saturn in mid- 1946 models of medium to large displacement. Giuseppe Gilera , however, soon realized that these bikes were not the most suitable to deal with the market, and therefore decided to appoint engineer Piero Remor of the study of an economic model, but with a four-stroke engine .
Design and prototypes

The goal of putting on the market an economical "125", but with a prestigious 4-stroke engine, is however the only one agreed between Giuseppe Gilera and Piero Remor, whose different technical concepts are already in the design phase. Remor, the father of the four-cylinder front-end engine, destined to dominate world production up to the present day, seeks for a modern valve-to-head distribution , while Gilera, linked to company traditions, prefers to point to a proven and economical lateral valve distribution. After a long series of discussions, enlivened by the sharp character of the two characters, Remor resigned, oblivious to the neck , to design the engine with side valves.
At the Milan Motor Show in 1948 , Gilera presented the prototype of a "125" (displaced at the time exempted from the bill) which was distinguished for the simple and clean line, but which was warmly welcomed by the public, dealers and the specialized press, Due to the modest performance due to the sophisticated design of the propulsion that developed 3.5 hp and allowed a speed of 70 km / h.

The need to switch to valve distribution on the head caused another technical clash between Gilera and Remor, about the option to rethink the engine completely, supported by the designer, and to modify the existing, supported by the " patron ". The iron arm between the two was once again won by Giuseppe Gilera and that is why the new engine is characterized by the bizarre front positioning of the rods and camshafts that could not find the correct position behind the Cylinder, without distorting the structure of the block.
In the Gilera establishment, the climate between the technical director and the owner became very tenacious, punctuated by numerous discussions on technical and economic details, leading to Remor's decision at the end of 1949 to abandon the Arcore house to move to MV Agusta , together with assistants Andrea and Arturo Magni .
The "125"

The new Gilera 125 was presented to the press and dealers on March 22, 1949 and, despite the troubled genesis, immediately met a general favor. Especially on the part of the public, with a purchase price similar to other 2-stroke models, it was possible for a large-scale motorbike branded with a 4.7-horsepower speed of 80 km / h. Perhaps the finishes and endowments were slightly lower than the duetempyst competition, but the new Gilera boasted a prestigious 4-stroke engine that guaranteed minimal fuel economy and good long-running durability. After the production of the 1st series , in September, the main problem of the "125" was the scarcity of specimens that could not satisfy the demand. In fact, most of the orders were not satisfied when, in December 1949, the 2nd series came into production, which included small improvements and the adoption of cushioned cushions. While busy with the workers' spasimo, the company could not build more than 500 specimens a month.
During the production of the 3rd Series , begun in June 1950 and credited with 5 hp, with improved distribution and new valve seats, the assembly rides designed by Giuseppe Gilera, then installed in January and February 1951 , were suspended, suspending production Of the "125". It resumed in March, with the production of the 4th series , called "Tourism", which saw the increase in capacity of the oil sump and, finally, the adoption of the bronze for the connecting rod instead of the rollers. The new "assembly rides", at full speed, could spin a thousand engines a month.
At the same time as the previous one, in April, the production of the 5th "Sport" series was started, equipped with a 13 liter fuel tank and a 7 hp engine that allowed a maximum speed of 90 km / h without altering fuel consumption. The 6th series , with small variations, came into production in February 1952 , ending in July of the same year.

The new law, which in Italy imposed the "125" marking and allowed access to motorways for motorcycles with a minimum capacity of 150 cm³ , decreed the production output of the "125" and its replacement with the "150" , After a total of 25,000 specimens built in the various series and versions.
For the sake of completeness, it should be added that in 1955 Gilera marketed a "125" derived from the "150" and named "Export" as it was intended for export, in particular in the Swiss Confederation , keeping it in the catalog up to 1959 .
The "150"

Presented in 1952 as the heir of the eighth of a liter, the 150th will be Gilera's best-selling ever, with 96,000 specimens (excluding those built in Argentina by the local branch). The engine was revised by Antonio Parolo, Franco Passoni and Luigi Piazza (under the supervision of the new director of the Gilera Experiment Service, Sandro Colombo), carrying the bore to 60 mm and maintaining the 125th race. The increase was due Even to the rules that imposed the bill of the eighth of a liter, until then exempted. Two versions available initially: Tourism and Sport , which were distinct mainly for the front suspension (parallelogram Tourism, Telescopic Sport). For both gears it remained at 3 ratios. Already in 1953 , Sport won a 4th gear.
The '53 also saw the catalog entry of Demonstration , the most advanced model built in limited series. These will be followed by Gran Turismo ( 1955 ), Super Sport and Red Super ( 1957 ). The production ceased in 1960 .
The "175"

It was introduced in 1956 under the name of 150 V , but was renamed almost G 175 . At the end of the year the range is expanded with Gran Turismo and Extra models (the latter features some features of the B 300 , as the chain primary instead of gears), while the G 175 is renamed Normal . In 1957 the Sport models (with the Gran Turismo engine) and Rossa Extra (with the type Extra engine) arrived. The range was later simplified in 1958 with the production output of Extra. The 175 remain in the catalog until 1960. 10 500 copies will be produced.

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