Wednesday, September 10, 2014

Honda CB750

When Motorcyclist Magazine celebrated their 100th anniversary in 2012, they thought it would be appropriate to choose a "Motorcycle of the Century." They chose the 1969 Honda CB750. They called it "the bike that changed everything."

There are lots of memorable motorcycles that created waves over the years, many people have their own favorites, but it was the Honda CB750 that rearranged the entire motorcycle market as soon as it came out. Honda offered comfort, reliability, and performance, all combined into a single package at a great price. Competitors stood there, slack-jawed, as they watched their own product mix get stale overnight.

As one motorcycle journalist described it referring to the then new Harley Sportster released the previous year and the holder of the title "superbike" prior to Honda's announcement: "The Sportster went from performance king to non functional bar hopper in just over a year. It hardly changed at all, really, but the world around it changed dramatically. It would have been interesting if Harley Davidson had taken up the challenge and pushed performance, at least in the Sportster line, instead of falling back on tradition and image. What might have been?"

British bikes, already struggling with problems started a steady decline. Kawasaki responded with the Z1 in 1971. A four cylinder, four-stroke, 750 cc bike was going through top-secret development prior to the release by Honda. The success of Honda's four caused Kawasaki to postpone the Z1's release until its displacement could be upped to 903 cc and sold as a 1000 cc-class machine. As the saying goes, "the rest is history," and the motorcycle market took off, never to be the same, but it was the CB750 that made it happen.

Honda's transition from the 1958 Super Cub to the 1969 "super bike" included a 250 cc and a 305 cc bikes called "Dreams." Although they resembled motorcycles from Harley and British manufacturers, they shared the front suspension and pressed steel frame from the Cub.

The most traditional bike in Honda's early product line was the 305 Super Hawk. The Honda CB77, or Super Hawk, was a 305 cc (18.6 cu in) vertical twin motorcycle produced from 1961 until 1967. It is remembered today as Honda's first sport bike. It is a landmark model in Honda's advances in Western motorcycle markets of the 1960s, for its speed and power as well as its reliability, and is regarded as one of the bikes that set the paradigm for modern motorcycles.

Robert M. Pirsig rode a CB77 Super Hawk on the trip he made with his son and their friends in 1968 on a two month journey from their home in St. Paul, Minnesota to Petaluma, California and back, which became the basis for the novel Zen and the Art of Motorcycle Maintenance: An Inquiry into Values. The novel never mentions the make or model of Pirsig's motorcycle, focusing more on his companion riders' BMW. Pirsig was, as of 2007, still the owner of his Super Hawk.

The Honda CB450 "Black Bomber" was the first truly "big" Honda motorcycle with a 444 cc parallel twin, dual overhead cam engine producing 43-45 horsepower (by extension, that is more than 100 hp per liter (1,000 cc) of displacement, another engineering milestone.

Appearing first in 1965 with a four-speed K0 model, and progressing through a series of models with various improvements and styling changes, notably a redesigned fuel tank and 5 speed transmission in the 1968 K1 model.

Honda (UK) planned a publicity event by entering Mike Hailwood as one of the riders in the Motor Cycle 500 mile production race at Brands Hatch during July 1966. Instead, Hailwood completed demonstration laps on a CB450 before racing began as it was unable to compete in the 500cc category, the FIM deeming it was not classified as a production machine as it had two overhead camshafts.

The basic CB450 engine was modified and installed in the Honda N360 car and the exported N600, the precursor to the Honda Civic.

Honda updated their product line in 1968 with the CB350, a 325.6 ccc (19.87 cu in) OHC parallel twin cylinder, four-stroke motorcycle produced through 1973. With its reliable motor and dual Keihin carburetors, it became Honda's best-selling model. More than 250,000 were sold in five years, with 67,180 sold in 1972 alone. In 1968 it was the best-selling motorcycle worldwide. The CB350 evolved during its production run with cosmetic changes and improvements to the suspension and brakes.

These early twins set the stage for the 1969 Honda unveiling of the CB750 at the Tokyo Motor Show in late ’68, although it didn’t hit the market until early the next year. It is impossible to overstate the impact this bike made, as the first modern mass-market four, and the first volume production bike to come with a disc brake.

Honda triggered a speedy evolution of motorcycle technology with its pioneering of the four-cylinder layout. It brought a reliable ride that many riders had not yet experienced in 1969.

The Honda CB750 is a motorcycle built in several model series between 1969 and 2003, and also in 2007. It is recognized as a milestone in Honda's successful introduction of the transverse, overhead camshaft inline four-cylinder engine that, ever since, has been the dominant sport bike configuration. Though MV Agusta had sold such a model in 1965, and it had been used in racing engines before World War II, the CB750 is recognized as the four-cylinder sport bike that had a lasting impact and is often called the first superbike. The model is included in the AMA Motorcycle Hall of Fame Classic Bikes.

Cycle magazine called the CB750 "the most sophisticated production bike ever" upon its introduction. Cycle World called it a masterpiece, highlighting Honda's painstaking durability testing, the bike's 120 mph top speed, the fade-free performance of the braking, the comfortable ride, and excellent instrumentation.

The CB750 was the first modern four-cylinder machine from a mainstream manufacturer, and the term superbike was coined to describe it. The bike offered other important features that added to its compelling value: electric starter, kill switch, dual mirrors, flashing turn signals, easily maintained valves, and overall smoothness and freedom from vibration both underway and at a stand still; later models (1991 on) included maintenance-free hydraulic valves.

Unable to gauge demand for the new bike accurately, Honda limited its initial investment in the production dies for the CB750 by using a technique called permanent mold casting (often erroneously referred to as sand-casting) rather than die-casting for the engines. Exceeding expectations, the bike remained in the Honda lineup for ten years, with sales totaling over 400,000 in its life span.

Until well into 1970, CB750s were made without die-cast engine cases. In truth, die-cast cases were lighter, stronger, and more oil tight. But it’s the early, "temporary-cast" models that are prized by collectors.

The venerable four spawned many copies, both larger displacement and some refined smaller versions such as Honda's own CB500 and CB550 fours. It was on the back of a CB550 Four that I made a journey from Colorado to Lewistown in the summer of 1976. I remember sitting in a bar with my friend Jack Barney … a member of the local county mounties. Just then his radio spoke up that there was a suspicious motorcycle parked outside with Colorado plates. Jack replied to the voice that he was questioning the suspect at that time.

Although that smaller Honda Four was a jewel around town, I have to admit it was a bit small for the long ride up I-25 through the Wyoming wind and the Montana hills. On my return trip a week later I recall intensely wishing it had a windshield.

Even though single and twin cylinder powered motorcycles are still most common, four-cylinder and even six-cylinder bikes are now spotted regularly on the highways and Interstates. The history of motorcycles included engines with more than two cylinders in the early days, but the two-cylinder models had dominated production up to this point. Both racing and street riding changed after the Honda four came out.

To quote from an SAE (Society of Automotive Engineers) technical paper written in 1969, "Combustion engines with up to 48 cyl have been built. It is shown that this is neither accident nor fanciness when high specific power output is involved. As is demonstrated on hand of equations [sic], the subdivision of a certain displacement into larger numbers of smaller cylinders brings about a substantial increase in power."

So the engineers agree. The manufacturers agree. The racers agree. The riders agree. I agree. Twins are cool, but "more is beter." It's a philosophy I've always tried to live with … that and "the one who dies with the most toys wins!"

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