The developed version of the P20 was ready for production in 1973.

Designated the P21, the msot important modifications included changes to the needle-roller bearings in the connecting rod, revised lubrication to the telescopic front fork suspension (with full rubber gaiters), the adoptions of a speedometer and increased stability to the cycle frame. A luxury version was also prepared for the capitalist market, with turn indicators (on the handlebar ends), tachometer, side panniers, and front mounted crash bars.
Between 1973 and 1974, a total of some 4 thousand P21 & P21 Luxury version were producedfor the domestic and export markets.