Reattino is the first Birel chassis mass-produced. It was introduced in  Milan in 1961, at the Kart Show, that is held during the International Exhibition of Cycle and Motorcycle. It is the replica of the chassis with which Walter Eleonori won the second prize in the race of the “World Championship”, that was held on the “Pista Rossa” on September 17th of the same year, in Milan (it was part of a list of International competitions organized by the Go Kart Club of America, that, at that time, all people considered a proper world championship, even if it was not world titled).

The chassis frame is rectangular. The rails are two overlapping tubes that join towards the front chassis, where it is welded together with the front tube (to be more precise, there is only one shaped and folded to “U” tube in the rear part, behind the axle bearings). The padded seat is in the middle of the rails and the back fixed to the rear center. An other center supports wheel and acts also as support for the metallic housing of the steering column. The column controls only one arm that turns the left wheel, while that on the right is controlled by a coupling axle. The tank is in the centre, between pilot’s legs. The wheels, the platform and the brake drum, mechanically controlled, are of light alloy, the axle is of Ergal. The stated weight is of 32 kg. On the class 100 model the engine is behind the seat, in a sheltered position, that it does not expose it to the air flow, therefore it must be forced cooling. Of Reattino, then, you also find the twin-engine model, for 200 Class, with joining plates corresponding to rails.

Birel also offers an economic model of Reattino, that it is called Rondine. The chassis frame is the same, but many parts that on Reattino are of light alloy, as, for example, the wheels, the axle or the platform, on Rondine are of steel, therefore the total weight reaches 36 kg.