Never heard of Bridgestone motorcycle...but from the internet:
Not familiar with Bridgestone motorcycles? Here's a brief synopsis:
In addition to the more familiar tire manufacturing nowadays, the company produced bicycles beginning in 1946, powered bicycles beginning in 1949, and motorbikes from 1958 through 1971. This grew out of an automotive part trading company in Japan run by Soichiro Ishibashi, the company name being taken from a literal translation of his name in English -- Ishi - stone, Bashi - bridge.
Exports to America began in 1963, via Rockford Scooter Company of Rockford, Illinois (later renamed to Rockford Motors). The first model was the '7', a fan cooled 50cc two-stroke with three-speed rotary transmission. The machines were initially sold via catalogue sales, such as Spiegel and Aldens. Dedicated dealerships were quickly established later on, but never grew to the scale of the other large manufacturers. Small-scale exports to other countries followed, with the bikes not reaching the U.K. and Australian markets until about 1968. The vast majority of motorcycles were destined for the U.S.A. market. The larger displacement models were virtually unseen elsewhere, even in Japan.
Several Japanese motorcycle manufacturers went under in the early sixties. Bridgestone was doing well and absorbed former employees of failed companies like Tohatsu and Lilac. Out of this came their most well known series of motorcycles, based on rotary valve engines, ranging in size from 50cc to 350cc. This line began in 1964, and were so advanced for the day they continued generally unchanged through 1971. Build and engineering quality reached a new high. In addition to 100% phenolic self-lubricating disc valves instead of the two-piece phenolic/metal seen on other makes (which tended to part company after a while), features included:
