This model went on to enter the 1951 International Six Day Trials. The bike was entered by the factory, being ridden by Bultó and G. Cavestany. In the early 1950s, Montesa entered many races in the 125cc class of road racing. These bikes featured six-speed, bolt on gearboxes, in semi-unit construction, with all gears running on needle-roller bearings. By 1956, these Montesa 125s were very competitive and took second, third and fourth places in the Ultra-Lightweight race at the Isle of Man TT.