George wrote:I wonder why Ducati made two engines with only 15 cc difference. 160 cc is a strange capacity, would that be to do with Spanish age/learner restrictions or perhaps using up old stock when 125 discontinued.
I can’t speak for the Mototrans products, but here’s the story as far as Bologna was concerned:
The 175 engine was made from 1957 though to 1960. Known as the Type A engine, it was also produced in a 200cc version.
In 1961 it was dropped in favour of the Type B engine which incorporated a number of significant modifications. This engine was conceived as a 250, but was also produced as a sleeved-down 200cc.
In 1964, Berliner asked Ducati to produce a model which they could pitch against Honda’s recently announced 160cc Hawk. Rather than sleeve-down (yet again …) the 250 Type B engine, Ducati bored out its 125cc engine, up till then produced mainly for the domestic market, to produce the 160 Monza Junior.
At Tom Bailey’s concession, the Monza Junior was the best-selling bike in 1965, with insurance being around 25% cheaper than for a 200cc.