One of the many high quality (and somewhat pricey) small displacement bikes from a company we now only associate with tires, the Bridgestone 175 Dual Twin was basically a baby sport bike with two of their 90cc single engines merged together.
The Dual Twin featured expensive rotary valves, fully-enclosed carbs, the first oil mixing system that Bridgestone used, and a “Sport-Shift” lever, a lever on th eleft side of the transmission that enabled a manual overdrive function enabling a top speed bump from 65 to about 80-85 miles per hour. The 177cc engine produced 20 horsepower and the bike weighed 271 pounds. At 25 miles per hour, this bike could return 129 miles per gallon! All that would set you back $599 back in 1970. For more on the Dual Twin, check out this scan of a road test from Cycle Magazine hosted on Bridgestone Motorcycle.
This example (VIN: TA1-03054) has roughly 4,300 miles and per the seller it “cranks, idles, runs, shifts, and stops very well.” Find this Bridgestone for sale in Greeneville, Tennessee with bidding up to $1,255 here on eBay.