Honda, Triumph, and the Race For the 750 Superbike

Honda’s own authorised history summarised what Harada’s US visit had revealed: ‘The majority of American riders, it seemed, did not judge motorcycles simply by how fast they could go. They also wanted responsive torque performance so that they could get the power they needed without downshifting.’

The American dealers’ push for bigger motorcycles echoed that of the company’s co-founder, Soichiro Honda. During a visit to Switzerland, Honda claimed that he had noticed how small a Triumph motorcycle appeared with a policeman on board. However, when the rider dismounted, Soichiro quickly realised that it wasn’t the bike that was small but the European rider who was big. Honda now understood that in spite of his company being the largest motorcycle manufacturer in the world, if the Honda Motorcycle Company was to grow, it must make bikes specifically designed to suit an international market rather than sell to those markets bikes made for Japan’s smaller-sized customers.

Soichiro Honda: Racer, Metallurgist, Manufacturer

Soichiro Honda was born in Komyo Village (today called Tenryu City), in Iwata County on 17 November 1906. He was the eldest son of Gihei Honda, a bicycle repair man and blacksmith, and Mika, a weaver. In April 1922, Soichiro left elementary school aged just fifteen to start an apprenticeship at one of Tokyo’s top automobile repair shops, Art Shokai. Under owner, Yuzo Sakakibara, the young Soichiro learned how to repair cars (and motorcycles), deal with customers, the importance of taking pride in your work, thinking for oneself, improvising solutions, and developing new ideas.

In 1923, Sakakibara, his younger brother, Shin’ichi, and some of the apprentices, including Honda, began making racing cars. Their first car employed a second-hand Daimler engine. The Art Daimler was soon followed by another utilising the chassis of an American car, a Mitchell, into which they installed the engine from a Curtiss ‘Jenny’ A1 biplane. On 23 November 1924, the car won its first race with 17 year-old Soichiro, accompanying Shin’ichi Sakakibara, as engineer. The success led to Soichiro becoming a successful racing driver and builder.

In April 1928, aged just 21, Honda finished his apprenticeship and was given the distinction Sakakibara awarded to none of his other students, of opening a branch of Art Shoki in Hamamatsu. However, following a near-fatal car crash in 1936 at Tamagawa Speedway, and a growing dissatisfaction with repair work, Honda set up Tokai Seiki Heavy Industries in 1937. The company manufactured piston rings for Toyota and the Nakajima aircraft company.

In his endless pursuit of improving the product, he went back to school to study metallurgy. During the war, Honda — who was colour-blind and had been deemed unfit for military service when, aged 20, he was called up in the mid-1920s — produced aircraft propellers, but his factories were destroyed by bombing raids and earthquakes and he sold the company to Toyota. After considering manufacturing textile machinery, he chose instead to make bicycles, 500 of which he adapted and installed military-surplus engines. Two years later, and short of funds, Honda secured the financial backing of 38-year-old Takeo Fujisawa and together they founded the Honda Motor Company in September 1948. In August the following year, Honda became the first post-war Japanese manufacturer to produce both an engine and a frame. Called the D-type Dream (after someone at a party to celebrate the first prototype described the machine as a ‘dream’), the 98cc single-cylinder two-stroke became a massive success, due in no small part to co-director Takeo Fujisawa’s marketing acumen.

Honda operated a meritocracy, he encouraged innovation and free thinking in Japan’s still post-feudalist society. The results were simply phenomenal: between 1961 and ’63, Honda’s exports grew from 50,000 to 338,000. By 1967, they had amassed 16 World Championships and 137 Grand Prix victories. At their peak, Honda was making more motorcycles per hour than Vincent produced in its entire 28-year history.

Honda Thinks Big

In February 1968, as Honda’s sales recovered from the recession of 1966-67 (thanks largely to the Z50 Mini Trail and newly-launched CB350 twin), Soichiro appointed Yoshirou Harada to head up a project to build a ‘big motorcycle’. Harada assembled a youthful team of about 20. His team included Masura Shirakura to oversee engine development, Toshio Nozue as frame designer, and Hitoshi Ikeda as chief stylist. Soichiro urged his engineers to think big, telling them: ‘the bigger the better’. However, whilst Honda’s message was emphatic, for Harada it was hopelessly vague.

At that time, the biggest displacement, large-scale production motorcycle manufactured in Japan was the twin-cylinder W650, a thinly disguised copy of the BSA A10 (originally manufactured by Meguro, then Kawasaki after the latter bought the factory). At the outset of the project, the decision on engine capacity remained unclear. However, that did not prevent the team from setting themselves very clear targets for the new machine, the main objective for which was to manufacture a motorcycle that had ‘superior output’ but would make ‘long-range, high-speed touring safer and more comfortable’.

To facilitate the collaborative process, the design engineers and production staff established some common goals, all of which were to incorporate the newly emerging science of ergonomics.

The bike had to remain stable at high speeds (140 to 169kph), yet be manoeuvrable in traffic. Its brakes must be reliable and capable of resisting ‘high loads’. To reduce rider fatigue, Honda’s engineers had to minimize engine vibration and noise and the designers were tasked to provide a comfortable riding position and easy-to-use and simple-to-learn controls. Lights and instruments were to be large and reliable. They had to be designed to help the rider make sound judgments and ensure they were easily visible to other vehicles. The team also had to extend the service life of each component and ensure the bike was easy to maintain. Finally, the design had to be original — yet still easy to mass produce using newer, better materials and production technologies (and it had to be particularly cutting edge in its use of surface-treatment technologies).

After capturing five consecutive World Grand Prix championship titles in 1966, Honda retired from racing the following year to concentrate on designing a new range of road bikes. Their years of campaigning meant the company could call on a wealth of knowledge accrued from developing sophisticated, multi-cylinder GP race-winning machines. But in developing their first large-capacity motorcycle, Honda were not only looking back to their past, they were also looking ahead. The team introduced computer systems — initially to streamline the various steps in the project bike’s development. Eventually, however the system would help them achieve greater efficiency in planning modifications during the prototype stage. It also helped reduce the time taken in designing the production line for the manufacture of the bike.

After considering the merits and demerits of various configurations, including V, horizontally-opposed, and parallel-twin layouts, the decision to proceed with a four cylinder in-line engine reportedly followed a meeting Soichiro Honda had with the head of Honda’s Californian office, Bob Hansen, in early 1968.

Hansen and three other regional managers had been invited by Honda to visit the Japanese factory. After a tour of the plant, the delegation was told that Soichiro was having his English lesson and would be late. Their guide therefore took them to see the research and development department, but not the test area as that was where they were developing the new engine. When Hansen eventually met with Honda, the conversation turned to the new bike. Bob, a plain speaking man who was perhaps bristling a little at not getting to see the rumoured 750 twin, turned to Honda who was sat next to him and responded to the great man’s declaration that they were going to build the ‘King of Motorcycles.’ ‘That’s good,’ said Hansen. ‘I hope it’s not a twin.’ Honda was puzzled. He asked why Bob would say that, and Hansen — mindful of the company’s successful GP-winning multis — told him that it ‘had to be a four, not just another twin’. BSA/ Triumph, he explained, were set to launch a triple very soon. The very least Honda could do, urged Hansen, was to go with a bike that had three cylinders, preferably four. Project leader Harada later wrote to Hansen acknowledging Bob’s influence on Honda’s decision in February of ’68 to go ahead with a four cylinder.

The first prototype was a four-cylinder 650 based on two CB350s. They also tried doubling up Harada’s double-overhead cam CB450, but found twin-overhead cams made the engine too large. Harada therefore elected to begin with a single-overhead camshaft design with a view to upgrading to a DOHC layout in about three years’ time. (The news that BSA/Triumph were developing a 750cc multi also settled the question of the Honda’s capacity.) Harada’s eventual choice of SOHC layout would be the basis of both the CB750’s phenomenal success and its eventual usurpation. The engine proved so successful, that it wasn’t three, but ten years before Honda introduced the DOHC engine, by which time several pretenders to its crown would emerge.

Testing took place at the Arakawa circuit near Tokyo and at the Saitama factory. Pictures of that first prototype appeared in a Japanese magazine in 1968 and show what looks like the SOHC engine fitted in a CB450 chassis.

Road Testing The Ogle-Styled Triples In America

Back in England, Ogle Design had completed drawings and mock ups of their makeover of the BSA/Triumph triples. Head of the company, Tom Karen, had assigned keen motorcyclist Jim English (owner and rider of a Triumph Trophy) to Ogle’s first motorcycle project. English told author Mick Duckworth in an interview thirty years later for the journalist’s definitive history of the triples that when, in summer 1966, Karen took him to the back of a workshop and removed the covers off a P2 prototype at Ogle’s office in Letchworth, the designer, who had joined the company the previous year after training in vehicle design with automobile manufacturer Ford, was excited. English saw what at first glance looked like a Triumph Bonneville. Then he noticed that the bike had three exhausts. It was clear to him that this ‘must be something a bit special’. Karen informed English that this was Ogle’s next project. English was to work alongside a specialist in industrial design, Australian, Byron Fitzpatrick.

BSA’s brief to Ogle indicated that they were after ‘a very flashy American look, like a Cadillac car’ English’s own preference was the aesthetics of the Café racer, a look very popular with. British motorcyclists at that time. Nevertheless, as English would recall many years later, he and Fitzpatrick were really to let their hair down ‘doing futuristic stuff’, out of which would emerge the triples’ signature feature: the silencers. Despite their later notoriety, when English presented early renderings of his ideas to the BSA committee, the triple-piped end pieces to the silencers proved the element they liked most. And although English never actually thought BSA would put his design into production, it did meet Doug Hele’s brief that their volume should be big enough to install reverse-flow internals to mute the triple’s characteristic howl. Both the BSA and Triumph triples would share the ray-gun silencers (as they were later dubbed); and the angular shapes of the fuel tank, seat and side panels — which echoed the Sixties idea of ultra modernity, Ogle’s trademark boxy style, and picked up on Hopwood and Hele’s squared-off engine finning. And Fitzpatrick brought to bear his knowledge of ergonomics for household appliances to the machine’s ancillaries. He designed push-button, handlebar-mounted horn and lighting controls (set into the front brake and clutch lever housings), and direction indicators comprising a single pair of winkers visible from both the front and rear (mounted each side of the headlamp).

Ogle Design’s sister company, Ogle Models, completed mock ups by March 1967. Triumph’s Chief Development Engineer, Doug Hele, was horrified at what he saw (especially the Trident’s square tank). BSA’s Assistant Export Manager, Peter Glover, whose job it would be to sell the Rocket 3, was called to Meriden to choose the best of three designs hanging on the walls of Bert Hopwood’s office. Not finding any of them to his liking, he selected the one he ‘disliked least’. Don Brown, BSA’s East Coast Vice President, was also a vocal critic of Ogle’s designs (he took particular exception to the Ray-gun exhausts, which reminded him of the 1959 Cadillac owned by Triumph’s West Coast distributor, Johnson Motors’ titular head, Bill Johnson). Yet the older Ted Hodgson, a senior BSA executive based in New Jersey, liked them (they reminded him of the pre-war BSA Sloper’s ‘fishtail’ silencers).

In October that year, Doug Hele and his mechanics (Alan Barrett from Triumph and BSA senior engineer, Clive Bennett, and Graham Saunders from Small Heath’s Experimental Department) shipped two Tridents and two Rocket 3s to the home of Triumph’s Western US distributor, Johnson Motor’s vice president, E.W. ‘Pete’ Colman in Claremont, California for secret testing. Using Colman’s home as a base, Johnson Motor’s (JoMo) technicians racked up 2,000 miles on the triples on twisty mountain roads and the scorching desert highways around Palm Springs, San Bernardino and Mexico, with Rod Coates and Ed Nemec of the East Coast distributors, TriCor, flying out of Baltimore to join them. Factory racers Gary Nixon and Gene Romero carried out speed tests at the Orange County Raceway drag strip outside Los Angeles. Key US Triumph and BSA sales staff also got to view the prototypes. The tests highlighted various issues, mainly electrical. However, whilst the Americans praised the triples’ handling, speed, and smoothness, according to Hele, they did not like their ‘bizarre styling’. Be that as it may, whichever components might have to change as a result of the Stateside findings, the tank and silencers could not be amongst them.

All the same, manufacturing requirements and the results from testing meant that not all of Ogle’s designs made it to production (such as Fitzpatrick’s handlebar switches, rejected in favour of Lucas items, which, though antiquated, came with the requisite federal clearances for use in the US; the air scoops on the oil cooler, which testing showed were inefficient; and detailing such as the BSA tank badges, the grab rail and some softening of the edges to the flat-sided side panels). However, not everybody agreed with the changes to Ogle’s design.

Triumph draughtsman Brian Jones told author Mick Duckworth that he thought diluting Ogle’s designs ‘seemed a bit unfair’. Jones felt that making a break from BSA and Triumph’s traditional styling made sense, given that Japanese designs were threatening to make British motorcycles look as archaic as the plants in which they were made (precisely how archaic was being amply demonstrated half a world away).

CB750 Production Hits A Problem

By 1969, Honda had selected the Saitama Factory (today known as the Wako Plant) to produce the CB750 Four’s engine and the Hamamatsu Factory to manufacture the body. Because Honda considered the CB750 strategically important to its plans to increase sales of other models in the US market, Honda America sent two engineers to join the staff at the Saitama Factory to test and check 300 items from a US rider’s point of view. Honda’s ambitions for the American market, however, were not new.

American Honda Motor Corp’s sales manager, Hirobumi Nakamura, shocked Triumph’s West Coast distributor’s Bill Johnson early in the decade when the JoMo boss invited Nakamura to a meeting with him and Don Brown, Pete Colman and Johnson’s business partner, Wilbur Ceder, to discuss Honda’s sales targets for the US. At that time, Triumph’s distributor was selling between 2,000 and 2,500 new motorcycles a year across its Western Territory of 19 US states. Johnson therefore considered Nakumura’s figure of 5,000 — which Johnson described as ‘a lot of motorcycles’ — unfeasibly high. Nakamura flabbergasted the American, however, when he clarified that this was 5,000 new motorcycles a month, not a year.

Honda, though, was much less certain about forecasting the CB750’s sales. As a result, and to keep investment to a minimum, each plant utilised production facilities currently lying idle, overhauling and modifying them to build the CB750.

At the ultra-modern Saitama Factory near Tokyo, where Honda elected to produce the Dream Four’s engine, staff were wrestling with the myriad challenges posed by manufacturing components for a powerplant quite unlike anything they had produced before.

Honda’s previous models used a split-type, press-fit crankshaft with needle bearings. However, the CB750’s four-cylinder engine employed an integrated crankshaft and metal bearings. Moreover, it wasn’t just a question of identifying the machining equipment they required. The team also had to decide on what assembly line configuration was right for manufacturing parts for which they had no experience making. They visited automobile manufacturers to acquire the knowledge they needed to plan the line. All the same, things began badly and efficiency was poor. Against initial production forecasts of 25 units a day, Honda were at first achieving daily volumes of just five (and less).

Things were also not going well in the English Midlands.

Production Of The Triple Begins

As part of BSA Group Chief Executive Harry Sturgeon’s strategy to maximise efficiency, Meriden was to concentrate on producing its twin-cylinder range, particularly Triumph’s cash cow, the 650cc Bonneville (the plant was at full stretch anyhow trying to meet the massive overseas demand for its twins). Anything else the Group produced that wasn’t a Triumph twin, BSA was to manufacture at Small Heath (where, unlike Meriden which relied heavily on outside suppliers for plating and pressing, the Armoury Road plant could produce almost every metal component on a motorcycle). However, nearly a fifth of BSA’s plant was up to 20 years old. According to Alistair Cave, the general manager in charge of production: ‘Some of the machinery to be used for three-cylinder production was the same as had been used to make the M-series BSA side-valve singles and C-series lightweights back in the Fifties.’

Also, despite the Board’s clear edicts at management meetings that the triple was a stop-gap model so production costs were to be kept to a minimum, their decision to produce two engine variants caused Cave headaches. Inclining the cylinder head for the Rocket 3 engine meant the company had to furnish the foundry with two sets of patterns. It also doubled the number of machining operations the large and complex gravity and die-cast aluminium alloy castings required (the crankcases and covers were supplied by outside contractors). The centre section of the crankcase shells alone needed 56 individual machining operations and 48 jigs, settings for which had then to be changed when the machinists switched from milling, drilling, reaming and tapping the A75 castings to swop over to T150 cases. It all added to time and costs.

Cave also lamented the company’s continued adherence to vertically split crankcases, which he and senior engineering and design staff had wanted to abandon for pressure die-cast horizontally-split cases as used by the Japanese. This would have simplified production and helped make engines oil-tight. Unfortunately, the Board over-ruled them, insisting they persist with antique designs based on the capstan lathe machining techniques used to produce the single-cylinder engines from motor-cycling’s earliest days.

Production processes were equally antique. Bob Heath, the racer and visor manufacturer, told Classic Bike magazine that when he worked on the Rocket 3 assembly line at the BSA factory, ‘One of my jobs was to rub the splines in the primary drive shock absorber chainwheel with a carborundum stone, by hand. It had to be done because the splines were slightly undersize, and wouldn’t fit on the clutch shafts. It was a boring job, but if I could do four a day, they could finish four more engines.’

Production of the triples began on 23 August 1968, after staff had returned to work following the plant’s summer closedown. To begin with, BSA set Armoury Road a modest target of 50 units a week, building up to 150 units (which would comprise both BSA and Triumph variants). Meanwhile at Meriden, already working flat out trying to meet demand for its twins, a track was laid to assemble twenty-five Tridents a day. As Cave and his team prepared for production of the triple during the spring, the BSA Group’s development centre in Umberslade Hall instigated a switch from the traditional British thread sizes to the American Unified system being adopted by the UK automotive industry. The move was intended to reduce costs. Instead, it caused disruption and simply added to Cave’s problems as taps, dies and thread gauges had to all be changed and assembly line staff spent time sorting out the correct fastener from amongst an array of similar looking but different thread forms.

Umberslade Hall

BSA Group’s research and design base (or Group Engineering Centre as it was officially known) was situated in a large, brick- and limestone-built country house in Hockley Heath near Solihull. Established by Lionel Jofeh at the suggestion of private consultants McKinsey, staff could peer through its leaded glass windows to see peacocks roaming the grounds and gardens. Jofeh had been appointed Managing Director in February 1967 following Harry Sturgeon’s departure due to ill health (he would pass away of a brain tumour just two months later). Jofeh joined BSA from Sperry Gyroscope’s aerospace division. Like his brainchild, Umberslade Hall, he was remote from most of the staff in Small Heath (which he thought a ‘muck heap’) and Meriden where he was rarely seen (no doubt shocked at the plant’s primitive facilities, especially if compared to what he was used to in the aerospace industry).

The R&D centre was a move to bring modern industrial practices to the BSA Group. However, Umberslade proved ruinously expensive (it cost the BSA Group around £1.5 million a year). Its technicians were non-motorcyclists who worked at a leisurely pace — wags called it ‘Slumberglades’ — producing ideas that paid scant attention to production requirements or customer needs. Although such a facility was an idea Bert Hopwood had wanted to introduce at each of the marques with whom he’d worked, he and his chief engineering assistant, Hele, never actually moved there (Hopwood thought the rooms too dark for draughting, and he missed the noise and din of the factory, which he felt were a useful reminder of where his designs would become reality).

BSA Invest In Plant For The Triple

Manufacturing Hele’s 120 degree throw crankshaft — the biggest BSA had ever dealt with — set the man in charge of production, Alistair Cave, challenges of its own. A one-piece forging, the crankshaft emerged from the drop forge with the three crankpins on a single plane. Following some machining, the crank was then heated up and twisted 60 degrees at a time, a practice which considerably reduced the number of machining operations. As ingenious, unorthodox, and time consuming as the process was, the finished crankshaft proved tremendously strong — if expensive. BSA had to buy a German-made grinding machine at a cost of £80,000 (around half-a-million pounds at post-millenium prices) to eliminate variations in web thickness encountered in early production.

Each of the 150 triple engines BSA were producing at their Armoury Road factory every working week was run briefly on a static test rig, oil was flushed through, drained, and the oil filters replaced. In addition, they checked one in every twenty engine’s output on a dynometer. Later, when production at Armoury Road was fully up and running, the plant selected completed machines at random and took them to the MIRA (the Motor Industry Research Association) testing facility near Nuneaton for comprehensive testing. Triumph had similar arrangements for monitoring the performance of the 200 to 250 Trident powerplants Armoury Road trucked the 12 miles to Meriden for installation in the chassis. Yet, despite the factories’ checking and testing, the early Rocket 3s and Tridents were to be blighted by a catalogue of manufacturing faults that only became apparent after the bikes were in the hands of the press or had left the showroom.

In contrast to producing the engine, manufacturing the triples’ chassis and cycle parts proved straightforward (if needlessly inefficient and expensive).

Each plant made its own frame following its own processes and traditions. BSA MIG-welded the Rocket 3’s chassis from steel tube just as it did for their 500 and 650 twins. Meriden, on the other hand, stuck with hearth brazing forged lugs and lengths of A-grade mild steel tube pre-shaped by Reynolds Tubes of Birmingham (because Meriden didn’t have the equipment to bend them themselves), which, as with Triumph’s twins, they would make up into front and rear frame sections that bolted together.

Production of the Ogle-designed fuel tanks that Doug Hele hated so much was carried out by the BSA Group’s usual supplier, the Homer Company of Birmingham, whilst the Armoury Road plant manufactured the triples’ ray-gun silencers using a 600 ton flat-bed press purchased specifically for the task. With its seamed joins along the top and bottom, Ogle’s design was actually easier to produce than the traditional cigar-shaped mufflers whose joins required considerable polishing to produce a seamless finish before passing to Small Heath’s in-house chromium plating shop. The finished silencer’s large surface area was, however, susceptible to showing up the slightest knock, and its weight, coupled with problems manufacturing the manifolds accurately, made it difficult and fiddly to handle on the assembly line.

BSA/Triumph Unveil Their 750 Superbikes

Rumours of a BSA/Triumph triple had been circulating in the press for some time, but, in early 1968, the US magazine Cycle found evidence of their development in the most unlikely of places. They were testing a BSA 650 twin and found it had three holes in the holder for its two condensers. For the magazine there could be only one ‘possible explanation’. The surplus hole was evidence that Lucas already had hardware in production for a three-cylinder motorcycle and that the two-wheeler itself could not be far behind.

In September 1968, the BSA/Triumph combine ended the years of speculation when they officially revealed the BSA Rocket 3 and Triumph Trident. Small Heath and Meriden had beaten the world’s largest motorcycle manufacturer to the market with a multi-cylinder 750. As the American magazine Cycle World said in their first road test of the Trident in its October issue: ‘… there isn’t another bike like it’.

Six thousand miles away, the Dream Four’s project team had just weeks to finalise the ‘King of Motorcycles’ before its debut at Tokyo’s Motorcycle Show on 25 October… and Harada still hadn’t secured Soichiro Honda’s sign-off of a key (and what would prove signature) component of the bike’s specification.

Reprinted with permission from Superbikes and the 70s by Dave Sheehan and published by Panther Publishing, 2013. Buy this book from our store: Superbikes and the 70s.