1981 – With the demise of the 75cc class a last ditch effort is made to conquer the new 80cc class.
With the successful 75cc as a starting point, which had been enriched in its road version by a hydraulic cooling jet, a special model is put together by the Frigerio brothers to take part in the European and Italian Championships.
The increase in engine capacity is achieved by a wider cylinder, the bore increases from 48mm to 50,5mm to reach 78,11cc and the power isincreased to an amazing 18hp at 11.500 rpm.
The general look of the motorcycle also undergoes some changes; the fuel tank is now orange-red, the fuel tank yellow, the mudguards and sides white.
The innovative solution of a water cooled system is underlined by the radiator mounted in front of the handle bars, housed within a single unit including also the headlight and the place for the racing numbers.
When introduced to the public the front mudguard was mounted low onto the wheel, but for racing the mudguard was mounted higher.
To ride this extraordinary special model Gino Perego and Mario Milani were roped in, whom it took almost until the end of the season to achieve fair results.
At the first trials for the Italian Championships, the new “radiator type” cooling system showed some deficiencies and did not allow the riders to achieve good placings.

At the Six Days of the Isle of Elba (5/10 October) the brothers Frigerio entered a team comprising of two 80cc and one 175cc, ridden by Cesare Bernardi.
Compared to the earlier version the 80cc was further improved and a electric water pump was installed under the fuel tank, to facilitate the water circulation, the slant of the rear shocks was also adjusted.
At the end of the Six Days Mario Milani conquered 2^nd place redeeming himself despite a lackluster season. At the same event Gino Perego, 5^th until the end, suffered a puncture during the last trials and skidded in, in 8^th place.
The best of the Frigerio-Rotax was Cesare Bernardi's, 3^rd in the 175cc class, who in a team with Gianpiero Findanno, KTM 250, Andrea Marioni, Zündapp 125 and Angelo Signorelli, Fantic 80, won the Silver Trophy.
Also here the differences between Bernardi's Frigerio-Rotax and the mass produced models was evident, especially in the rear geometry of the motorcycle which determined the new slants and anchor points of the shock absorbers.