Scott's Bridgestone Motorcycles!

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Here you will find technical information for repairing and maintaining Bridgestone motorcycles.

In addition, you'll find photos, advertisements, articles and owner stories.

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:


bulletClose-tolerance chrome-plated bore aluminum cylinders and aluminum pistons (same expansion coefficient)
bulletAutomatic oil injection (direct to bearings on the 350 models)
bulletRugged and accurate 5 and 6-speed transmissions (needle bearings and no false neutrals)
bulletSwitchable 4 speed rotary (town) 5 speed return (highway) transmission. (175, 200 models)
bulletDry racing clutch (350 models)
bulletPrimary kick start -- no hunting for neutral if stalled; just pull the clutch (350 models)
bulletHi output alternators (175, 200, 350 models)
bulletHi output ignition (175, 200, 350 models)
bulletDual-leading-shoe (dual cam) race style drum brakes (175, 200, 350 models)
bulletReversible controls (British vs. Japanese) (350 models)
bulletAdjustable suspension (350 models)
bulletRubber cushioned motor mounts
bulletLots of heavy triple-plated (copper, nickel, chrome) plating and candy-apple paint
bulletLarger "American" size frame (350 models)
bulletNo-slip Simul-suede upholstery (175, 350 scrambler models)
bulletFor more, click here.

Bridgestone was the most successful marquee on Japanese racetracks in small displacement categories during the mid-sixties, eliciting considerable attention by American riders.  This prompted the 'SR' series in 90, 100 and 175cc, which were slightly modified race-only versions of the road-going models.  The road-going 175 was enlarged to 200cc in 1970.

Many of the cutting-edge engineering features found on Bridgestones were not exclusive, but nowhere else could so many advanced features be found in one place.  So why did production cease?  Many reasons are cited.  The advanced engineering and quality came at a price.  The 350GTR was introduced at over $900US in 1967.  That is $6500 in today's dollars, and was at a time that a basic new Ford or Chevrolet automobile could be purchased for $2000.  A Honda or Yamaha of similar displacement could be had for around $700US, which would be equivalent to $1500 less expensive in today's dollars. Though this did nothing to squelch desire it did inhibit sales.  Cheaper products are easier to sell to the majority of buyers when the differences in quality are not so apparent just sitting new on the showroom floor.

While production and profits were doing well, the motorcycle production was more of a sideline to the tire manufacturing.  Profits earned didn't stay within the division, but were absorbed by the tire division.  Unconfirmed rumors spread that other Japanese motorcycle manufacturers made it clear to Bridgestone that if they pursued their competitive behavior in motorcycles they would find themselves with no OEM market for their tires.  Both tire and motorcycle production took place in adjoining sections of the same crowded factory.  Expansion of one would be at the expense of the other, unless heavy investment was made in a new factory.  The increasing value of the yen vs. the dollar was cutting into profits and didn't bode well for the future either.

It soon became apparent that corporate interest in continued motorcycle development was waning.  Late sixties "new" models were merely warmed over variations of earlier ones.  Dealerships began bailing out.  Environmentalist pressure against two-stroke engines in the U.S. was also on the rise.  Following the 1971 model run, Bridgestone closed the motorcycle division.  Most of their tooling was sold to a Taiwanese firm named BS Tailung, which resumed production of replacement parts for previous models, and introduced a series of small motorbikes distributed by Rockford Motors; the Chibi, Tora, and Taka.  Virtually all NOS parts available today originated in Taiwan rather than from Bridgestone.  BS Tailung ceased operation in 1975.

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