Bultaco began manufacturing motorcycles in 1958. Senor Bulto left Montesa when they decided to pursue a non-racing policy, taking other disgruntled engineers with him. For the next twenty years Bultaco produced many successful motorcycles based on a simple one cylinder two stroke engine. The Metralla was their streetbike model and enjoyed popularity in the late sixties after a Isle of Man race win in 1967. In the late 70s the company dissolved due to labour unrest and market pressures.
From Two Wheel Horse, a book put out by Bultaco in 1971 as a promotional item. Part sales brochure, part owners manual, it's a lovely presentation of the company's product line.