HONDA CB750 SOHC

Discussion in 'General Discussion / News / Information' started by HIKO, Mar 4, 2009.

  1. HIKO

    HIKO Ol'Timer

    40 YEARS SINCE MOTORCYCLE HISTORY WAS MADE.

    Part 1.

    The older GT-riders maybe still remember it but most probably don’t. This year is 40 years since the mother of all Super Bikes, the first modern motorcycle, the first in-line four produced in high volume, the first disc brake motorcycle the incredible HONDA CB 750 was introduced and on sale on the market.

    After the introduction Honda CB750 was to become the benchmark for all new motorcycle models for ten years. It is probably quite difficult for people who where not active motorcyclists by that time to really realize what impact this model had on the motorcycle market.

    In this post and in other posts coming in the next few weeks I will try to analyze how the Honda CB750 Four was born and what impact did it have globally on the motorcycle market from very many aspects. The CB750 SOHC did not only not only revolutionize motorcycle manufacturing and design. It caused the total collapse of the English motorcycle industry. It also created or at least gave new power to the “Cafe Racer” trend that started from the ACE café in England but because of the Honda CB750 Four it was spreading quickly to California and the rest of US. It also gave a new dimension to the “Chopper concept” which up to now mostly was a HD phenomena. The CB750 HONDA Four was also gave birth to a huge accessories industry, everything from engine parts, frame kits, exhaust systems, fiber glass tanks, transmission systems to chrome and high polished alu parts. The CB750 Four was manufactured in such huge amounts that it was profitable for accessory companies to manufacture special parts for the CB750. Just to give you an idea about the amounts, about 1 million Honda CB750 SOHC was manufactured, a figure BMW just reached as a total figure for the whole BMW motorcycle factory life….
    The CB750 was also very active in Racing even if Honda officially had withdrawn from Road Racing. Instead Honda sold kits that transformed the standard bike into racing machines. Honda was also very active in Endurance racing both in Suzuka and in Europe. The Europe part was mostly handled by the French importer Japauto.
    At the early stage of the CB750 Honda also dominated drag racing in US together with Russ Collins and his CB750 based dragster. Hopefully you will not find these posts to boring or presented with too much old, antique information. On the other hand I think it is important for all motorcyclists to understand the CB750 phenomena because it changed the motorcycle world.

    It is important also to know that at this time Honda was not a very solid company financially. The expansion and growth of the company had outrun their financial means many many times and Honda had been on the brink of bankruptcy many times. Soichiro Honda was a gambler and high risk taker not only in business matters but also in his personal life. He had a serious Car racing crash with an airplane engine planted into a car chassis in his early twentieth. He crashed several times with motorcycle when racing. He crashed airplanes many times and everything that was technically interesting, had much power where things that Soichiro Honda could not resist. The same thing in business. New projects, technically interesting was enough to make Soichiro Honda happy. He didn’t care about money but luckily for him his partner Takeo Fujisawa was the person who saved Honda Motor Company from bankruptcy several times.

    In the middle of the 60:s Honda sale in USA declined and something had to be done because Honda had invested heavily in the US market and the establishment of American Honda had been an real high risk project. The US market for big Bikes at this time was about 50-60,000 bikes per year dominated by HD, Triumph, BSA, Norton. Common for all these brands was low quality and oil on the shop floor. It was this market Honda wanted to enter hoping to change the negative sales trend, again a high risk project….

    Soichiro Hondas (the co-owner of Honda) decision in 1967 to start to develop a “big motorcycle” is the source to many, many rumors. One as told by Mr.Soichiro Honda himself, was that during a business strip to Switzerland, he saw a motorcycle police on a Triumph and thought that the motorcycle looked small but when the police left the motorbike he realized that it was not the bike that was small, it was the driver that was big. He then understood that Honda, despite being already the world’s largest motorcycle manufacturer, must start making motorcycles for the International market not selling motorcycles made for small sized Japanese on the International market.

    According to another rumor the project manager for the Honda CB750 Mr Yoshiro Harada (who also had been in charge of the CB450 development) was visiting the USA trying to convince American dealers to sell better of the 1965 launched CB450 DOHC torsion controlled valve motorcycle which he said had more power and handled better than any HD. Triumph, BSA or Norton and it did not leave any leaking oil on the show room floor.. The CB450 was developed on the request of the American dealers who wanted a little bigger bike than the CB77 305CC “Hawk”. Anyhow the 450 was a compromise because Honda wanted to sell the 450 both on the Japanese market and the American market. But despite that the American dealers and consumers knew that the smaller capacity Hondas had more power than the English competitors the dealers just asked him “why make small when can do big”

    During his trip to USA Mr. Harada also first time heard that Triumph and BSA where about to launch a 750 three cylinder so it was quickly decided that the new Honda must be a 750 Four cylinder in order to keep the “big advance”. At the same time it was decided that the new CB 750 Four must have at least 67 Hp because the biggest HD had 66 Hp…
    Another important input to the decision process was that by 1966 , Honda decided to withdraw from the World Grand Prix circuit after having captured five consecutive championship titles in the historic 1966 World Grand GP circuit, beginning the very next season. Upon that announcement, the company turned toward its primary target: the development of high-performance consumer machines. Thus it would achieve through the application of technology obtained in road racing.
    Officially the CB750 Project started in February 1968 when Soichiro Honda gave the project to Yoshiro Harada and he picked up a 20 member design team to help him. As a thumb rule he got a very broad advice from Mr. Honda “The bigger the better”

    The 650 cc displacement size was the largest to be found in Japan, (This according to Honda Japan. Anyhow this is not correct even if Honda is referring to the 650 Kawasaki “BSA A10” copy, originally made by Merusa before the factory was sold to Kawasaki in the 60:s. Honda forgets the Rikuo Harley 750 and 1200 CC license made bikes which where still manufactured until 1958 and sold still in the 60:s) Yet these bikes accounted for only a few percentage points in the overall market. Harada therefore decided to develop a bigger model, as an obvious nod to the U.S. market. However, the request given by American Honda'"the bigger the better,"seemed quite vague to him. Based on that advice alone, it would be difficult for Harada to determine the right displacement.

    Probably the first engine prototype was a four cylinder 650 based on two CB350 Hondas. They also tried to use the CB450 DOHC engine and double it but they quickly found out that the engine will be too big with a DOHC engine so Mr. Harada informed the project team that we will start with a SOHC engine and in about 3 years we will upgrade it to a DOHC version. Because of the huge success of the SOHC Honda 750 it took them 10 years to introduce the DOHC engine….The 750 Four decision was made then when it was clear that Triumph/BSA will launch the 3-cylinder 750.

    The more specific targets were as follows:

    1. Ensure stability during high-speed cruising (between 140 and 160 km/h) on highways, yet retain an ample margin of output for effective maneuvering in traffic.

    2. Provide a braking system that is reliable and resistant to high loads by anticipating frequent rapid decelerations from high speeds.

    3. Minimize vibration and noise in order to reduce rider fatigue during long-range cruising. Provide an ideal riding position for comfort and the proper operation of controls based on human-engineering principles, and design the mechanisms so that the rider can easily learn how to operate them.

    4. Ensure that various ancillary devices, such as lights and instruments, are large and reliable. They must be designed to help the rider make sound judgments and ensure sufficient visibility for surrounding vehicles.

    5. Extend the service life for each device and ensure that it provides for easy maintenance and servicing

    6. Create original designs that also are easy to mass produce by utilizing newer, better materials and production technologies. This applies particularly to cutting-edge surface-treatment technologies.

    A team of about twenty members was assembled on behalf of the development project in February 1968. The design of the CB750 FOUR had officially begun. However, Honda was already the industry's leading producer of motorcycles, thanks to the popularity of its classic Super Cub. By introducing the CB750 FOUR, the company planned to become the world's top manufacturer in terms of quality as well as volume. This model's competition, however, would be formidable, since the pack included comparable models from Triumph, BSA, BMW, and Harley. Therefore, the new Honda would have to offer a superior level of performance and reliability in order to lead the field.

    The first picture of a prototype was in a Japanese magazine in 1968 from a racing circuit named Arakawa close to Tokio.

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    The first prototype pictures. Probably the engine was fit in a Honda CB450 chassis for testing The two first pictures are from the Arakawa circuit the lower one from the Saitama Factory.

    The bike was first presented at the Tokyo Show on the 28.10.1968 ( this date is sometimes referred in Honda:s own papers as 1966 and 1969 but I am quite convinced that 1968 is the correct year.

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    Tokyo Show with a separate engine.
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    Tokyo Show

    Before the exhibition Mr. Harada presented two prototypes to Mr Honda and asked him which one he preferred, one had a drum brake in front from the CB450 and the other one had a Disc brake. The answer was easy for Mr Honda who was a “tech freak” Mr. Honda's reply, though, was simple and direct: "Well, of course we'll have to go with disc brakes."
    !!!. Unfortunally Mr Harada and his team had not have time to develop the disk brake system and their experience was only the result from tests with an accessory Lockhed bought on his recent US-trip and a spying mission at the Lockhed factory in England. They were not sure if they could live up to the next spring production target.
    They still had three problems unsolved, how to get mileage on the brake pads, how to get rid of the typical “noise” from the pads and how to get a no-rusting surface on he disk without loosing any braking power. A good disk is rusting but that was against their “goals”, the bike should look tidy even after a rain. To speak frankly Honda never solved the brake problem, it was very noisy and especially when raining there were no braking power at all. The stainless steel brake disk anyhow didn’t rust…..
    Okay this was an introduction then sit down and relax when looking at these two You tubes first presented on Discovery Channel.

    The test ride with the 1969 model is not correct it is not a 1969 model, maybe more a 1971 model but it doesn’t matter.


     
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  3. HIKO

    HIKO Ol'Timer

    [size size=12]Why am I so dedicated to Honda CB750 Four SOHC?[/size]

    Part 2

    As you probably very soon will find out is that I am very passionate about Honda CB750 Four SOHC (means single overhead camshaft). The reason for that is very easy. On my 18th birthday November 1 1969 I picked up the first 750 Honda ever sold in Finland. I even think that the sale in England started first in 1970. The bike was a genuine K0 model with the famous sand cast engine. I still remember as yesterday that incredible feeling I had when I reved up the four cylinder engine, what a sound for the ears, and how beautiful was the sight on the green lighted tachometer when the engine responded. I drove out in below zero temperature to visit my local coffee shop where all my friends were waiting. Nobody has ever seen anything like it and you can be sure that I was more than proud about the bike which had cost me about 1.500 USD. For that money you could buy a new small car, but who wants a car when you can have a candy red Honda Four. My motorcycle experience at this stage was a Honda C110 Super Cub, a CB92 Super Sport Benly 125cc, a Yamaha YDS5 250 cc, a Triumph TT100SS 500cc and my last bike a Triumph 650 Bonneville. But this four cylinder marvel was as from another planet, smooth and no vibrations, fantastic finish and the Candy red color turned into black under the yellow evening light.

    After this first CB750 Four I stayed loyal to Honda Fours for the next ten years and I probably had about 10 of those SOHC models and drove close to half a million km with them.

    The reason why I write about this fantastic machine is not only because it is 40 years anniversary. Last January I was invited to the Finnish Motorcycle Expo. The Expo is quite huge, the biggest in North Europe with 80.000 visitors during a long weekend, despite -15C!!!! This year Orange County Choppers owner Paul Teutul Senior, famous from American Choppers on Discovery Channel, was flown in as a special attraction. I was invited by the Finnish Japanese Vintage Motorcycle Club who had a 300 m2 stand only devoted to the CB750 Four celebrating its 40th anniversary. On the stand were plenty of my old CB750 Hondas all restored to original or even better. The main attraction was my first, in 1969 bought CB750 K0 sand cast model, shining even more than as new on its own podium. Probably the bike was more photographed than all the new Yamaha Veemax, R1, CBR:s, Harleys etc. There is a tremendous boom in Europe for restoring old Japanese bikes and the most prestigious of them all is the CB750 Four.

    I was standing at the stand for three days, and I met thousands of my old friends, most of them which you could not recognize at once, 40 years don’t make us more beautiful… and everybody wanted to talk about all those good old days when Honda introduced the CB750 Four. I had a nice time, growing old is not always painful.

    During the exhibition I realized that it is time to memorize all these memories and this thread is a first try to do it.

    In order to give you some ideas about my expo experience I will give you some pictures from the exhibition.

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    Would you believe that this bike is 40 years old

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    I don't think the bike shined as much when it was new.
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    Would You believe that the girls combined age is less than the bike's

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    I think that the new owner Jari Lehtinen has put more than 20.000 USD into the restoration project

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    Here I am posing with former Road Racer Martti Pesonen, who was one of the early "Flying Finns" on the Worlds Champion Road Racing Scene in the 60:s and 70:s. The reason why we are posing in front of my old CB750 Four was that I borrowed Martti that very same bike on the Isle of Man during the TT-Races in 1970. Martti was racing there with his Yamahas but with only a few training sessions with the traffic closed he needed desperately more practice time to learn the 60km+ long circuit and since I was visiting Isle of Man as a normal tourist I kindly borrowed Martti my CB750 so that he can learn the circuit as a normal tourist.
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    The poster in front of the bike is a photo of me when I picked up the bike as new from the Honda importer on the 1st of November 1969
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    The blue 1973 Honda CB750 reg AO-870 that the young boy is admiring is also one of my old Honda CB750:s. The bike is totally restored. The story behind the bike is that we drove with this bike, together with one other CB750 more around the world in 1974

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    This is an article from Motorad Jan 1970 about Elefanten Treffen, a very famous annual winter rally at the old Nurburgring. The magazine had a picture of us with the loaded 750 Honda on our way around the world.

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    And here we pose with the same bike about 30.000 km later in Gardena LA California in front of the Californian Honda Four Club:s president's house.
     
  4. techy5025

    techy5025 Member

    I own two of these bikes in the US....one a "K0" that I have owned since 1969 and the other a sandcast restored off ebay. Great bikes. I still remember the first time I rode one in '69...I thought it sounded like a car!

    I ride both bikes regularly. Thanks for the great history and memories! :D

    Jim
     
  5. Muzz

    Muzz Ol'Timer

    The Kawasaki Z1 was the one that did it for me, but no denying the CB750 was the bike that changed the rules.... By the way Hiko, fantastic article... Thanks
     
  6. Azoulay

    Azoulay Ol'Timer

    Hi Friends, Hi Hiko,

    Congratulation for your posts, perfect, and in fact it reminded me that this bike was one of the most easy to thief...

    You could find the engine as well on the S800 Honda car...quite funny at this time.

    The CB 750, I rode more than one I promise....In France it acquire the name of Quatre pots for the 4 exhausts...
     
  7. Dougal

    Dougal Ol'Timer

    Great post Hiko, thanks.

    Had one myself and thought at the time it was a revolutionary design.
    Coming from several Brit bikes to the CB 750 that's not difficult to understand.

    i thought it was the best bike in the world with which you could anything; and you did it by going around the world on it!
     
  8. Ian Bungy

    Ian Bungy Ol'Timer

    Great Article Hiko and Thanks for Sharing!!! You are a Legend and Constant Source of Information and Amazement to Me :shock: I Still Remember Seeing My First CB 750 4 when I was Still going to School, Our Neighbours Son Brought the First one in Our Farming Community of New Zealand and It Was Magic 8) The Guy was Up there with God when Riding it!!! And after that One Time Surveying the Bike I was Hooked and started My Quest to Get a Bike for Myself ( Had to Learn to Ride first of Course :roll: ) Eventually I achieved My Goal at 14 with a Brand New Suzuki GT125, I didn't have a License and everyone thought what a Strange Bike for a Farmer??? But i had different Views and Still have I think? Anyway the Rest is History, I have Owned Loads of Bikes since But the One that Started it Was the Honda CB 750 4 and I never even Owned one 8) Good On You Mate, "A Memory is worth a Thousand Words"
     
  9. Franz

    Franz Ol'Timer

    Top information Hiko, no historican could do it any better !! Can remember the CB750 as the real big step in technology although never owned one myself, your former "red one" is restored in a perfect way just from the looks on the photos. Congrats & thanks once more for this amazing article of yours !!!!!! Cheers, Franz
     
  10. HIKO

    HIKO Ol'Timer

    Part 3

    THE AMERICAN INVASION

    The American introduction happened in Las Vegas at the 10th American Honda dealer convention January 1969 American Honda had some sales problem in USA and they needed the Honda CB750 desperately to change the negative sales trend. Mr Harada and Soichiro Honda himself flew in for the convention and Honda had a few prototypes there for testing and some bikes were driven up from California to Nevada. After the convention a few bikes toured the dealers on the west coast. The models were partly the prototype with drum brakes from the CB450. Probably all the bikes were prototypes with different specifications. It also seems that the rumors that Honda did a special pre-production assembly line in order to deliver samples to American dealers and people with special connections to Honda, is correct. The amount of bikes later found, that are not from the first K0 production lot and not real prototypes is quite enormous.

    When American Honda Ceo Kihachiro Kawashima introduced the bike and told the dealers that the retail price would be USD 1495,. All dealers burst into thunderous applause when they heard the price. The price was 1400-2500 USD cheaper than its competitors!!!!! Very soon the Honda was pre sold at a “premium price” about 400 USD over the list price even before the real production had started.

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    This is one of the Las Vegas Bike

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    This blue bike is supposed to be one of the Las Vegas Prototypes, later many people say that it is a retrocopy of it. Anyhow it looks nice with the 450 tank.

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    This bike is for sure one of the bikes at Las Vegas. The colour never went into production. Pls note the style on the side cover's badge and the drum brake


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    This bike is from the first promotional materials. Pls note the "wrong' side cover badges despite a disc brake


    DAYTONA MARCH 1970.

    As a part of the American launch Honda America also had 4 drivers in the Daytona 200 AMA Race in March 1970. The drivers used modified standard CB750 bikes with about 90 Hp. Some people say that the bikes were very much standard others say that they were specially developed for Daytona at Honda Racing in Japan. based on the experience from Hondas 1969 victory at Bol Dor 24 hrs race in France in the 6 hours Suzuka race in 1969 Despite that one driver crashed out in the practice and two riders had to quit because of cam chain problems the race was won by the veteran rider Dick Mann and Honda took all the glory they could from it even before the new bike was commercially available since all available bikes were pre sold.

    The story why Honda entered the race is quite interesting. First of all the AMA had been forced by BSA/Triumph to change their "pro harley rules" and allow 750 bikes with overhead valves not restricting that motor type to 500 cc. This made Harley's side valve 750 racing engine old fashioned for the 1970 race. So Harley built a new OHV XXRT V-twin engine for the race and hired Cal Rayborn to drive it. The race was also very important because BSA/Triumph had several bikes in the race with their new 750 triple and the American BSA importer Birmingham Small Arms, had flown in Mike Hailwood as one rider and hired rising stars like Gene Romero, Gary Nixon and David Aldana as the other riders.

    At first Honda didn't want to enter the race but Honda America's Mid Western Sales Manager Bob Hansen told Mr. Harada that since he already had sold 1000 CB750:s he knew that plenty of them will be find at the starting grid for the 1970 Daytona 200 miles. He just mentioned that off course none of these privateers will be able to win... Harada then contacted Honda's racing department and a quick decision was made to build 4 bikes for the race.

    Honda entered the race with 4 bikes but only appointed three riders, all European,The team consisted of Bill Smith, Tommy Robb and Ralph Bryans, all experienced road racers. The 4th driver Honda asked Bob Hansen to find and asked him to become team manager. At this point Bob Hansen established a racing team and was later after Honda very successful also with Kawasaki.

    Bob Hansen knew veteran driver Dick Mann from before and he knew that he was just fired from BSA being to old, and Dick Mann accepted.

    Honda flew in 4 bikes with different specifications on the camshafts.
    One had 96hp, two had 92 and another had 89.

    Instead of the European stars or BSA's young-gun riders, it was Mann who crossed the finish line first on the Honda.

    Dick "Bugsy" Mann's was fastest in qualifying and ended up in the front row with an average speed around the 2.5-mile tri-oval of 152.82 mph. In the race, Mann took a perfect start after the second lap he opened a 40 meters lead. The race was grueling. It was the old circuit so there was no back-straight chicane then. The bikes have to drive at maximum rpm for a sustained period, and this took a toll when the rubber cam-chain tensioners, first on two of the english riders bikes and in the middle of the race also on Mann's bike disintegrated . With 10 laps remaining, Mann's huge lead over Romero was just 12 seconds-and he was losing a second per lap. But the 36-year-old veteran's cool, calm, collected attitude helped him keep the bike together. He crossed the finish line in first place, 3 seconds ahead of Romero, the Honda running on just three cylinders with less than a half-quart of oil left in its pan. Mann was as cool as normal about that day: "Bob Hansen prepared the machine well and I rode it as best I could, just as I was contracted to do." After the race Honda ended the cooperation with Dick Mann who returned to Daytona the following year on a BSA and won again on the way of winning his second AMA Grand National Championship.

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    Dick Mann and and team manager Bob Hansen (I assume) before the race.

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    The whole Bob Hansen Honda team

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    Dick Mann waiting for the start.


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    Dick Mann in Paddock

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    Dick Mann taking the start

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    And Honda took all the glory they could from the win despite that it was very close to a fiasco...

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    Dick Mann and the winning bike (or copy the original is supposed to be in France) at the AMA Motorcycle Hall of Fame exhibition.

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    Dick Mann in the Victory Lane together with Gene Romero and I think Dave Aldana
     
  11. HIKO

    HIKO Ol'Timer

    Part 4.

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    EUROPEAN LAUNCH.


    The European launch happened in April 1969 at the Brighton Motorcycle show, followed up by testing launches for the press at Nurburgring in Germany and Le Mans in France. Unfortunally I haven't been able to find any pictures from these occasions.

    The success was immediate both in the USA and in Europe. The official date of starting deliveries of the CB750 was the 6.6.1969 but for example in Canada there are plenty of bikes registered already in April 1969 as well as in the US. Honda probably improvised and put up temporary product lines in order to satisfy the demand.

    Just to give you a hint about how huge the success was I can tell you that Honda had anticipated a yearly production of 1.500 pcs. In a few weeks after the launch this was changed to a monthly figure and a few weeks later the monthly production target was increased to 3000 pcs. This of course caused tremendous troubles for Honda even before even one bike was in production.

    PRODUCTION.


    Hondas original plan was to manufacture the frames at the Hamamatsu factory and the engines at an idle factory in Saitama (nowadays the Wako Plant) American Honda sent 2 engineers to the Saitama factory for testing different items from an American consumers point of view. Since it was Hondas first big bike; sales forecast were not very reliable and Honda wanted to use idle capacity in order to keep the overall investment as low as possible. Most of the production lines were modified from power product manufacturing, to the Honda CB750 production. In the start they could only make 10 bikes per day but in a few weeks they had to increase it to 25 per day and then up to 100 per day. Already in early 1971 the production had to be moved to the Suzuka Factory where they invested in new production lines in order to keep up the demand and quality.

    One special problem was that Honda's previous models used a split-type, press-fit crankshaft having needle bearings. However, the four-cylinder power plant in the CB750 FOUR employed an integrated crankshaft, metal bearing and horizontally split crank cases. At the Saitama Factory, the staff wracked their brains trying to identify the right machining equipment and line configuration to produce a part they had no former experience in making. They even visited automobile manufacturers in order to acquire some knowledge they could use to plan the production line. As a result of this the first models had a sand cast engine crank cases since the molds was much more cheap and suitable for low volumes. When the volume exploded Honda had to invest in metal die cast machinery for the crank cases. Today those first sand cast engines are the most valuable Honda CB750:s as restoration projects and they even have an own club;

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    If you want to buy one sand cast CB750 Honda try this place but be prepared to pay about 20.000 USD. The bike cost new 1495,. USD so it wasn't not so bad invest to buy one and keep it for a while.....l

    http://www.worldmotorcycles.com/

    The sand cast crank cases did have some problems. The cast not being so strong you could easily crack the crank case by tightening the oil filter case to much. Honda reacted quickly to this problem by making new versions of the oil filter case as well as changing the bolt size from 14mm to 12 mm, everything delivered with the first “guarantee” package free of charge to the first production bike owners.

    It is quite fascinating how Honda managed to keep up such a high quality standard despite the initial, huge manufacturing problems. Honda partly solved the problems by moving personnel from the Honda Civic car plant to the Honda CB750 production line. They also had to open up temporary extra production lines in order to keep up with the demand. Honda also started to use computers both in the product development as well as in the production management, this a lesson they have learned from the racing bike experience.

    HONDA CB750 PRODUCT LINE.

    Despite Mr. Haradas rather pessimistic forecast of a 3 year product life for the CB750 SOHC model before it must be replaced by a DOHC model, the Honda CB750 SOHC was manufactured for 10 years before it was replaced by the 16 valve DOHC engine in 1979. Why changing a winning concept?

    The CB750 SOHC was manufactured in principle in three different versions. The K-series, the F-series and the A-series.

    The K-series were the original CB750 with four separate exhaust. The F-models were more sporty. had 4-1 exhaust system and a disc rear brake. The A-model was a failure were Honda thought that new American customers would buy the Honda 750 if they didn't have to change gears manually, because they were used to American Automatic Cars. The idea was maybe good but the sales result was very poor.

    The first production model was called K0
    even if some “hard core fans” declare that the first model was only called CB750 Four or HM300 as the project was called. Anyhow the specifics for the K0 was carburetors controlled by a 1-4 split carburetor cable, rather bulky side covers with the Honda Wing badge, a same color air box, lamp cover and lamp holders painted in some color and a short chain guard being the most visible specs. The K0 had a sand blast engine up to September 1969 and engine number between CB750 1000001 to CB750 1007414.

    K0 owners were later in the 1970 presented a quite huge “guarantee package’ which included new carburetor cables, new sprockets with bigger front and smaller rear, new damper rubbers for the rear sprocket, a front sprocket chain guard or chain guide, a 12 mm oil filter bolt (instead of original 14mm) etc.

    This also told about some of the problems people had with the new model. The carburetors could easily been “stacked” with fatal consequences, Honda had big problems with the final transmission and people tightened the oil filter to tight especially on the sand cast engine which cast was not so strong.

    Honda's rear chain problem was severe. Most consumers thought by that time that Japanese chains can not be trusted, you must have a Renold chain or some German brand. But what happened when you put a non original chain on the bike, the chain was broken in 5 minutes often with a big hole in the crankcase as the result. Honda tried to fix the problem by changing the sprockets from 17/48 to 18/45, introducing different rubbers to dampen the rear sprocket movement and by creating a front sprocket guard/guide protector which actually only increased the size of the hole in the crank case when you “cut” the chain. But the only right solution was to ONLY USE ORIGINAL CHAIN. The Daido or DID chain was a very good chain, I think it was the first O-ring chain and specially developed for the Honda CB750. But it took some time before our attitude against Japanese chains changed and the importers changed the mark up on the chain in order to make it commercially available. The same process we had to go through with the Japanese tires because everybody knew (thought) that Japanese tires are not good…..How stupid we were….

    The chain problem also created a huge after sale accessories market. Some German manufacturers developed an oil sealed chain cover where the chain was swimming in oil. Others (like my self) developed duplex chain sprockets. The idea was not bad even if it stole some power. The main point was that you could use cheap industrial duplex chains instead of expensive original chains and you could easily do 50.000 km with a duplex chain. One negative thing was that you could not use the original chain cover.

    The K0 was delivered first in two colors candy red and candy blue. Later models were also delivered in candy gold.

    I don't show any picture of the K0 here because I have showed too many pictures of my old K0. Instead I show the first Honda poster, which really was beautiful with all chrome parts shining like chrome on the poster. I had one in my sleeping room's roof so that I could see every evening before sleep while waiting for my own bike to arrive.

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    And here are the technical specs:

    Original Specifications from the 1969 CB 750

    Engine - 736cc, Air cooled, transverse four cylinder, four stroke, SOHC, 2 valve per cylinder.
    Bore x Stroke & Compression Ratio - 61 х 63 mm & 9.0:1
    Induction & Ignition / Starting - 4x 28mm Keihin carbs & Electric/ Kick
    Max Power - 69 hp @ 8000 rpm
    Transmission / Drive - 5 Speed Chain
    Frame - Tubular steal duplex cradle
    Front & Rear Suspension -Telescopic forks non adjustable & Dual shocks, preload adjustable.
    Front & Rear Brakes - Single 290mm disc & 178mm Drum
    Front & Rear Tyre - 3.25-19 & 4.00-18
    Dry-Weight - 239 kg
    Fuel Capacity - 17.1 Litres
    Top Speed - 192 kmp/h

    And here you can see what the press and other experts thought about the bike:

    (copied from Trollhättan MC home page)

    Honda 750 Four K0 press releases

    "Your Honda dealer will have it soon. The Honda 750 Four. When you twist the throttle, remember one thing. You asked for it."
    - Honda ad, 1969

    "Single overhead cam, four cylinders, four carburetors and 67 ponies at 8000 rpm. Without a doubt, the wildest engine to come along in many a moon!"
    - Motorcyclist, July 1969

    "It was the neatest thing I've ever seen. It had an electric starter, that was one of the biggest things it
    had going for it. Every big bike at the time, you had to kickstart those rascals. Not this one. It sold
    itself. All you had to do was let someone go ride it. It was about that easy. They'd come back with a
    grin from ear to ear, you'd know you had a sale."
    - Mike Dreyer, general manager Dreyer Honda, Indianapolis, Indiana

    "The disc brake on the front of the Honda is absolutely fantastic. It is the standard by which all brakes of the future will be judged."
    - Cycle, March 1970

    "It was a very exciting time. Honda had developed enough of a reputation that customers knew this
    thing was gonna be a real runner. Everybody was excited about being able to buy something with that kind of performance for the kind of prices we sold them for - pocket change, today."
    - Bill McLean, general manager Colby Honda, Woodland Hills, California

    "It had an introductory price of $1295. That didn't last very long. The bike was instantly a success."
    - Bob Schultz, former owner Bob Schultz Motors, St. Louis, Missouri

    "It is hard to keep from raving at the way the hardware on the chassis has been arranged to allow what must be the ultimate angle of lean for any big - bore ... It is nearly impossible to ground the 750,which allows as much, or more banking than the Superhawk."
    - Cycle World, August 1969

    "The Honda is very forgiving. The power comes on without any sudden rushes, and it's
    relatively simple to power drift the slower corners."
    - Cycle, March 1970

    "CB750s? I sold the hell out of them. At time the CB750 came out, the 750 Triumph Trident also was just out, and there was no comparison between the two. The Honda was much more refined. Without a doubt it was a better product. I sold probably 20 CB750s to every Triumph Triple I sold. The very few diehard riders who bought the Triumph 750s, every single one of them traded it back in on a Honda. I was a diehard Triumph fan myself and I hated to see that happen, but the British motorcycle industry had its head in the sand way too long."
    - Larry Lilly, owner Larry Lilly Honda, Lancaster, California

    "I bought one of the first 750s to come into this country in 1969. The two things I liked most about the 750 was that it was faster than a Harley and it had an electric starter that really worked."
    - Mel Mandel, CB 750 owner, Los Angeles, California

    "This engine has such an unusual amount of torque that the gearbox is hardly needed."
    - Motorcyclist, July 1969

    "The 750 is in an extremely mild state of tune, with intake / exhaust valve overlap being not much more than that of a good touring car ... Honda didn't go all - out with a double overhead cam layout; it must be remembered that the benefit from the extra cam would be doubtful for a large - bore touring engine. Honda considers the reduced head size of an sohc engine to be of greater advantage."
    - Cycle World, August 1969

    "We went to the dealer convention and saw it, I think it was in Las Vegas. We were really impressed with the way Honda people demonstrated it. They put a glass of water on the seat, revved it up, and the water didn't spill. Then they put a nickel on the cylinder head - put it up on edge - and it wouldn't tip the nickel over. I don't think anybody had heard of a motorcycle engine that wouldn't vibrate. Later,demonstrating it to customers, we tried to stand a nickel up, but never could get it in the exact spot.We did put a glass of water on the seat, and it wouldn't spill. That impressed customers."
    - Helen Musselman, owner Musselman Honda Center, Tucson, Arizona

    "It was the best thing that had happened to motorcycles in 20 years. It just totally turned
    motorcycling into a more well rounded activity. Electric starting, no sparkplug fouling, just total reliability. They were so smooth and fast. We started roadracing one soon after they came out my brother John campaigned one quite well. They were bulletproof."
    - Dave Bettencourt, owner Bettencourts Honda, West Bridgewater, Massachusetts

    "Those bikes definitely caused a stir in the store. I remember that at one point we had 10 people standing in line waiting until I could get to them to do the sales paper work. They were quite a seller."
    - Joy Neuschwanger, office manager Faymyer's Honda, Denver, Colorado

    "A lot of our customers were in awe. We got just one in at first and it didn't stay around too long. We'd sell them in bunches. A guy would come in with his friends, we'd sell maybe three or four CB750s at one time. Now, we don't do that. I remember one week, we moved maybe 20 CB750s."
    - Robert Garrett, manager Garrett Honda, New Orleans, Louisiana

    "There just wasn't anything else like the CB750. These were the days of the muscle cars; in unofficial drag races the Hondas would generally clean up. The engineering was a generation ahead of anything else, and it was engineered to last a long time. The only dissatisfaction was from the person waiting to get one - the wait was a couple months."
    - Ray Van Zeist, owner Don & Roys Cycle Shop, Brookfield, Wisconsin

    "I remember my first time sitting on a 750, thinking how much bigger it was than my CB450. Riding that beast down the road at a brisk pace and looking down at those cylinders jutting out from under the gas tank, I realized this was more than a motorcycle; I was riding a visceral locomotive."
    - Gary Christopher, manager American Honda Motor Co., Inc.

    "It came out at a time when everything seemed to be status quo. All of a sudden this bike comes out,sounds great, has great power, stops good; it just did a lot of things really good, except for handling, but we didn't notice that too much because other bikes didn't handle that great, either. It got people excited again about motorcycling. The acceleration was important, but it was the sound as much as anything - that four - cylinder thing."
    - Chuck Keys, president Imperial Cycle Sales, Buffalo, New York

    "I had to have one when I first heard that sound. Those four pipes wailing as the revs climbedmade me shiver with lust. That sound is as much a part of the art of the CB750 as is its versatility, comfort and durability. It's just about perfect."
    - Barty Sommer, president CB750 Preservation Society

    "When those bikes were first introduced, it was a feeding frenzy. It was a four - cylinder, something new and neat, and it was fast. It had overhead - cam technology. We had a lot of people come in and look at it. Those were the good old days - it was a lot more fun, things were a lot simpler. I'd like to find one again so I could restore it."
    - Lane Jacquay, owner K&L Honda Sales, Fort Wayne, Indiana

    "The look, the sound, the feel, what more is there to say? Honda's CB750 is the bike, period.As long as there's at least one in my garage, I can die a happy man."
    - Jerry Beasiey, collector, Danville, California

    "Honda, as usual, has dared to do something that no one else would do, and because of this, seems to have another winner on their hands."
    - Motorcyclist, June 1969



    The next K-version was the K1
    . It had new more slim side covers, a black air box, more stylish side cover badges, carburetors controlled by one pull and one push cable, the control lights moved from the meters to a separate panel integrated with the handle bar fixer. The front sprocket shaft also got a chain oiler which didn’t work so well. There was also hundreds of other minor changes.

    [​IMG]
    HONDA K1

    The next model was K2 and it was a long runner, especially for the European market where the K3-K5 models were never officially sold according to Honda (which actually is not really correct) so Honda made the K2 model up to 1976 for the European market. Again there were many minor changes but the most visible were that the lamp cover became black with the lamp holders chromed and the side reflects got bigger in size. According to some people the power was also dropped because the cams were changed but officially nothing changed with the power figures.
    [​IMG]
    HONDA K2

    Then the next model was the K3. Officially it was not sold in Europe. The changes was again several but mostly not visible. They solely improved the bike by focusing on small details. Most visible was the new two color tank design which followed on all models up to K6. It also got bigger mirrors, new design on all control switches that turned turning lights automatically off. Another new feature was a new front disk design with warning spots for wear out brake pads and a water guard for the front disk. Also suspension was changed again both front and rear and they tried to use the experience from the CB500 Four which handled much better. The engine got lower profile cams together with new exhaust, probably because of tighter regulations. Anyhow Honda didn’t change the official technical specifications for this model either .

    Considering that Honda created one of the first true Super bikes (and by this set an example that brought all the other manufacturers into this market) you might have thought that they used more attention to the performance side of things in order to keep the edge, They also now had competition from Kawasaki’s Z1 and Suzuki’s GS 750 and later GS1000 all these models being DOHC engines and much more powerful than Honda CB750. Yamaha also tried to compete with Honda with the total fiasco model TX750 a bike that was withdrawn from the market silently. But the main focus of the CB-750's evolution was by then in the opposite direction. It is widely known (or thought) that early pre-production prototypes were quicker and somewhat less civilized than the Fours actually delivered into customers' hands back in 1970, and subsequent development has moved the bike further away from the pure performance concept. Smoothness, silence and reliability have been paramount considerations. Their aim was to make an almost perfect bike even more perfect. By this time many other Super bikes are faster and at least a couple handle better, but none were as slick, and reliable, as the Honda C750. True Harleys Sportsters, Triumphs twins and the Norton twins had been in production as long but they never used their long market appearance to improve the bike as Honda did with the CB750. Honda used the time to focus with incredible attention on details.
    [​IMG]
    Honda CB750 K3

    And then it was time for the new version the K4.
    Again hundreds of small changes but none very visible.

    [​IMG]
    HONDA CB750 K4

    Ant the same with K5. Some new colors and many small changes but none visible.

    [​IMG]
    Honda CB750 K5

    And everything continued with the K6 which was also imported to Europe

    [​IMG]
    HONDA CB750 K6

    But then came the K7 for all markets. Everything new except the reliable SHOC engine, but now a little de-tuned. It had a new frame, new tank, new carburetors with acceleration pump for gasoline injection, new exhaust pipes, new front fork, 17 inch rear tire, 630 drive chain. Honda tried to make this model more suitable for cruising and touring in order to improve the sale of their more sporty F-line. Actually the bike got a little boring and dull reputation.

    Anyhow it was a very good bike. I had one and I drove the whole summer season without problems and for the winter season I put on a Watsonian side car and drove 20.000 km in the winter season without any problems. I had great fun with the sidecar (even if an original K7 is not very suitable for side cars without modifications). My biggest problem was that I and the police had different opinions about whether you are allowed to drive the right hand corners with the side car high up in the air. It cost me some tickets and a short suspension of my driving license.

    [​IMG]
    HONDA CB750K7

    And then we have the last K model the K8
    which was only sold in the US. The saddle was more customized and the engine was from the F2 with new pistons, bigger valves and more power.

    [​IMG]
    Honda Cb750K8

    And then we have the F series. Production started in 1975 and ended in 1979 with the F3. I think below is the first model even if it is a 76 model F1 but I think the 75 model and the 76 model were same. Some times the F models were Honda CB750 Super Sports because on the tank there was sticker saying “Super Sports”. Clearly Honda’s intention was to give the F-series a more sporty image while doing the K-series more cruising/touring oriented. F-series was a total different bike with new fram, tank,4-1 exhaust and a double piston rear disc brake.

    [​IMG]
    Honda CB750 F1

    [​IMG]
    Honda CB750 F1

    And then we have the F2 with a more powerful engine with bigger valves, new pistons and a new cam shaft. I bought one in England in 1977 when the pound had collapsed and the bikes were cheap for us. I smuggled it successfully back home with plates from some of my other CB750:s.(the crime is already to old to be investigated so don’t worry)

    [​IMG]
    Honda CB750 F2

    [​IMG]
    Honda CB750 F2

    And then we have the last F model the F3. The bike now got comstar wheels and double brake discs in the front.

    [​IMG]
    Honda CB750F3

    And then we have the A-series
    It was a model only designed for the American market according to the idea that American consumers are used to automatic cars and therefore they want automatic bikes as well. Their plan didn’t work. People driving motorbikes like to dawn gear and up gear manually, that is a part of the fun. So the A-series never took off, despite a huge investment from Honda in both product developments
    and advertising just to give you an idea about the bike and Honda’s philosophy behind the bike I show these ads;

    [​IMG] [​IMG] [​IMG][​IMG]
    [​IMG]
    [​IMG]
    [​IMG][​IMG]

    Honda also had a Police model. I haven’t been able to find any sales figures for these models, so probably they are integrated into the sales figures for the “civil” models. I have seen some Honda papres where they complain that it is difficult to sell the CB750 Police model because, especially in the western world Police didn’t trust the Japanese quality. How wrong they were….Anyhow I saw in 1974 that they had sold the 750 Four police bike to many countries like Iran, Iraq, Pakistan and of course Japan. Enjoy the pictures.

    [​IMG]
    [​IMG]
    [​IMG]

    And in the end of this thread I have collected some of the first ads and brochures for the CB750 SOHC, the bike that changed the motorcycle world.


    [​IMG]

    [​IMG]
    [​IMG]
    [​IMG]

    [​IMG] [​IMG]
    [​IMG]
    [​IMG][​IMG]
    [​IMG]
     
  12. monsterman

    monsterman Ol'Timer

  13. HIKO

    HIKO Ol'Timer

    HI MONSTERMAN.

    Yes everybody is waiting for a CB750 Replica but the pictures you showed are more retro than replica. What people actually want is a close to 100% copy of the first CB750 SOHC. I don't think it would be so difficult for Honda to upgrade the old production line. molds and everything and make a true Replica. Maybe it comes at Tokyo Expo in the Autumn....

    Jerry, being an active motorcyclist in the UK at that time don't you have any memories from The CB750 SOHC?

    In my next post I will present all the chassi modified Honda CB750 SHOC, manufacturers like Rickman Brothers, Seeley, Dresda, Paul Dunstall, Egli, Rau, Bimota, Eckert, Nico Bakker,, Zerchot Honda, Martin Honda etc.... Good old memories.

    HIKO
     
  14. DavidFL

    DavidFL Administrator Staff Member

    Aha, now you're talking - Rickman, Seeley, Paul Dunstall, Egli...
    Hiko bring it on mate. All this modern history is good for us young fellows on the forum. I love it, so please keep it coming. You're a star.
     
  15. monsterman

    monsterman Ol'Timer

    When the CB750 came out I was 11 years old but by the time I got into bikes at 14 they were very common ,I actually preferred the CB500-4 which I rode when I was 19 but my mates brother built a DRESDA CB 750 based on Dave Degens Bol-Dor racer.
     
  16. HIKO

    HIKO Ol'Timer

    Oh sorry Jerry

    when I met you a few times in Pattaya I thought that you looked old......

    Just a joke!!!!

    HIKO
     
  17. irv327

    irv327 Active Member

    All those wasted teenage years lol...
    Having owned a cb750 and a Yamaha xs650 twin, I can say the big advantage was that the Honda did not vibrate at all. I recall sitting at a stoplight feeling each revolution of the 650's crankshaft send a shockwave up and down my spine.
    Part of Triumph's downfall has to do with the Labour party's economic suicide policy in the early 70s. (like we now have with enviro-evangelists)
    It is rather bizarre that England was and still is the centre of formula one engine development, yet nobody at Triumph bothered to tap those resources.
     
  18. HIKO

    HIKO Ol'Timer

    Coming SOON
     
  19. DavidFL

    DavidFL Administrator Staff Member

  20. Hondaman

    Hondaman New Member

    I wish to also thank Hiko! A great story, and not unlike my own!
    I am a huge. lifelong fan of the CB750, since it first appeared in the USA in 1969. It took me until 1970 to be able to get one, and I worked in a Honda shop at the time! Their popularity here can seldom be understood in the rest of the 'modern' world today. I have even written a book on how to rebuild them, and I participate in this with owners all over the world, doing exactly that.

    Thanks, Hiko!
     
  21. DavidFL

    DavidFL Administrator Staff Member

    Sad news, Hiko the author of this post has passed away.

    http://www.gt-rider.com/se-asia-motorcycling/topic/lost-another-rider-and-a-source-of-knowledge

    He was a mine of  info on motorcycles, motorcycling in Thailand &  a wonderful gentleman.

    May he rest Rest In Peace.
     

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