Specifications: 124 cc two-stroke single, six speeds.

Ducati tinkered with two-strokes over the years as a way to expand their customer base. In any case, the company was making questionable decisions in the 1970s, cancelling the 250-, 350- and 450-cc singles and struggling to make competitive parallel twins. The last two-strokes planned by Ducati were two 125-cc bikes in 1975. The Sperimentale street bike never saw daylight, but the 125 Regolarita Six Days was produced from 1975-77. Despite looking like a real enduro bike, the 238-pound Six Days was heavier. Despite a revision in 1977, which reduced weight, the bikes were cancelled relatively early in the production cycle. This makes surviving examples very rare, and with low indicated mileage this example is one of the more difficult items needed to complete a Ducati collection.