1964-bridgestone-super-7_1
Compared to contemporary motorcycle designs worldwide, Bridgestones were among the most advanced. While the typical and most common two-stroke engine is a piston port induction design, Bridgestone along with Kawasaki, experimented with a “rotary valve” induction that better controlled intake and exhaust. Bridgestones also incorporated primary kick starting which means even with the transmission in gear, you just pull in the clutch and kick, there’s no need to find neutral. However, Bridgestone’s rotary shifting when improperly operated could offer unintended shifts from top gear to first.
1964-bridgestone-super-7_7
Another form of sophistication was the early application of chrome on aluminum cylinder bores, as well as oil injection. And, seeking new markets, Bridgestone, like Honda, offered electric starting on even their small motorcycles like this Super 7.
Bridgestone was formed in 1930 to produce truck and automobile parts, but moved into tire manufacturing in 1931. As with Honda, motorcycle manufacturing began immediately after World War II. Not having a large dealer network, starting their sales in America around 1963, some Bridgestones were sold through department stores like Aldens much as Sears and Wards sold imported motorcycles. But Bridgestone’s biggest market was direct sales of tires to Japanese motorcycle and auto manufacturers, so around 1972 ceased its (competitive) motorcycle manufacturing and focused on their core business, tire manufacturing. Bridgestone made motorcycles for only about 25 years. The Bridgestone GTR 350 twin is the largest and fastest of their street bikes. Bridgestones live on in the hands of proud collectors like Thomas Zucarro who graciously loaned his Super 7 to the National Motorcycle Museum. A wide range of Japanese motorcycles are on display at the Museum from rare late 1950’s J Model Hondas to a one-owner 1977 Kawasaki Z1R with an interesting story.
Specifications:

  • Engine: Two-Stroke Single
  • Type: Air-Cooled, Rotary Valve Induction
  • Bore & Stroke: 54mm x 54mm
  • Displacement: 50cc’s
  • Compression Ration: 8.7 – 1
  • Ignition: Battery, Coil & Points
  • Carburetor: Mikuni
  • Horsepower: Seven
  • Primary: Gear Driven
  • Final Drive: Chain Driven
  • Transmission: 4-Speed Rotary Shift
  • Starting: Kick and Electric
  • Frame: Backbone, Pressed Steel
  • Suspension: Leading Link Fork / Swingarm, Dual Shocks
  • Brakes: Drum, Front and Rear
  • Wheelbase: 49 Inches
  • Wheels/Tires: 2.50 x 17 / 2.50 x 17
  • Weight: 245 Pounds
4 replies
  1. David Van Grinsven
    David Van Grinsven says:

    Thanks for sharing this bit of history. It brought back some fond memories of my youth. I learned how to ride on a Bridgstone 90CC. It was my best friends motorcycle. We put many miles riding around the court where his family lived. Both of us were 14 years,old so not legal to drive on the road yet. That didn’t stop us though. Their court was the perfect place to learn. It was about a 1/2 mile loop around with minimal traffic and no cops. I remember it had the rotary valve and rotary shift as well. It made learning to shift gears very easy. I also remember that it had two rear sprockets. We could easily add a few links to the chain and run the larger sprocket. Then we had a fairly capable off road bike. I was quite impressed with it’s hill climbing ability. Those were the days.

    Reply
  2. Mike O'Brien
    Mike O'Brien says:

    My first motorcycle was a Brigstome Sport 100. I can confirm the shift from fourth to first made for some interesting riding but it was a good little bike to learn to ride on. Thanks for memories.

    Reply
  3. Jukka Konola
    Jukka Konola says:

    My first motorcycle was a Bridgestone 200. It was a rotary and white with black knee pads and scrambler pipes. Wish I didn’t sell it and I still have the original shocks in the barn. I remember the 350s and they were nice. Bought it from a seller of ag equipment and snowblowers etc. out of Townsend MA (Think it was Sheppard’s).

    Reply
  4. Mark Dickerson
    Mark Dickerson says:

    This was my first motorcycle when I was 12 years old. I had so much fun on it. I now have two Bridgestones that I’m in the process of restoring 48 years later.

    Reply

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