Leopold Mila was made Technical Director and Permanyer's son Javier, was to be Sports Assistant. Work began right away on designing a brand new all-unit-construction 175cc engine that by 1960, would power the latest Impala sports roadster model. This engine would form the basis of the company's future trials and motocross machines. To promote sales of this model, three Impala's were taken to Africa where they covered over 12,000 miles of terrain, most of it being off-road. Back in Spain, Pi was busy winning the Spanish motocross and road race championships and working on a new 250cc version. Following its introduction in 1965, the 250 engine would be the cornerstone of the company's future success. Mounted on the new 250 Scorpion scrambler, Pi won the Spanish championship again in 1966 and the similarly engined Sport roadster won the Barcelona 24-hour endurance road race. In 1967 the first Montesa trials models appeared and in 1968 retitled the Cota, Pi won the Spanish Trials Championship. After adding this title to go along with the road race and six motocross titles, he retired from competition to devote his full energy to bike development. In the decade following, Montesa had unprecedented growth around the World and one has to remember that unlike Bulto's bike, the Bultaco, Montesa only sent a small percentage of its production to the States, concentrating mostly on the European market. Trials models were offered in many different sizes 25, 49, 125, 175, 250, 348 and 349, as were motocrossers 125, 175, 250, 360 and 414. This also included a line of street and Enduro models also. In 1973, the VR (Vehkonen Replica) was released and set the standard for 1974, as did the 348 Cota did in 1976. Ulf Karlsson won the World Trials Championship on a Cota in 1980.
By 1981, another round of economic unrest in Spain began to hinder motorcycle manufacturers. Strikes and a shrinking market left Montesa as the only major motorcycle concern in the country; however they were in need for a major influx of capital in order to continue to survive. A loan from the government and shares sold to Honda (to establish a European manufacturing base for their commuter bikes) helped production continue. Indeed, one of the governments stipulations was that Honda would guarantee that production would not stop. Honda was prepared to stockpile trials bikes and to sell them off at a loss in an effort to reach Europe's more profitable market and to bypass restrictive import tariffs. In July 1985, a major reorganization took place and a large amount of money from Honda was received. By then, only two trials models were offered and the workforce had dwindled to a mere 152 employees. A year later, there were further financial moves between Honda, Spain's government and the Permanyer family, leading to Honda buying the majority of the family's remaining shares. Honda now had an 85% holding and spent another $5 million on modifying and updating the factory. Montesa was still active in World Trials competition throughout the 1980s and into the 1990s. Even though reduced to only offering one model, the Cota, such riders like former World Champion Eddy Lejeune and Andrew Codina rode the bike to good results in the mid-'80s. In 1992-93, the liquid-cooled Cota 311 was produced; this was to be the last "real" Montesa. In 1994, a new model, the 314R, was introduced. This model featured an HRC Honda powerplant with many other components from Honda. Montesa-mounted Marc Colomer won the World title in 1996 and the 315R followed in early '97. The 315R had a run of 7 years, taking Dougie Lampkin to many world championships, and was replaced by the technically advanced four-stroke Cota 4RT in 2005.