SUZUKI RE-5
One upon a time, rotary motors were going to revolutionise the two-wheeled world. Frank Melling recalls why Suzuki’s attempt was less than successful
One upon a time, rotary motors were going to revolutionise the two-wheeled world. Frank Melling recalls why Suzuki’s attempt was less than successful
Motorcycles fail for many reasons. Research and development can be lacking, production facilities inadequate or the launch of the bike poorly executed. Rarely, very rarely indeed, a manufacturer can do everything right and still have a sales disaster on its hands. The Suzuki RE-5 Wankel is such a motorcycle – a catastrophe of such epic proportions that it genuinely threatened the very existence of the Suzuki factory. The biggest problem with the RE-5 is that the engineers actually believed their own PR. Worse than this, they convinced Suzuki management that all their equations, graphs and computer analyses would bring about a sales bonanza the like of which Suzuki had never seen in its fifty year history. They were wrong. When Honda, Yamaha and Suzuki withdrew from Grand Prix racing at the end of 1968, the Japanese lacked a showcase for their skills. During that decade, the Japanese had proven themselves masters of technological innovation with everything from Honda’s iconic, six cylinder 250s to the wondrous, three cylinder 50 produced by Suzuki. If the rider of the day thought about state of the art technology his default position was Japanese. Meanwhile, Concorde and Boeing’s 747 made their first flights, and Neil Armstrong set foot on the moon. In this febrile, can-do-anything atmosphere, engineers in all the Japanese factories became very excited. They were most enthused with the Holy Grail of the internal combustion engine – the ti f wer plant with virtually no moving tion. Enter centre stage the Wankel ngineers really do love Wankel engines e they appeal to their inner purity. any engineer about what excites or her, and they will radiate joy at ngs which work wonderfully well and ve supreme simplicity. On paper, the Wankel engine is just such a creation. The idea is that a rotor, shaped ather like a three sided wedge of cheese, spins round inside an oval shaped chamber. A shaft is mounted eccentrically through the cheese wedge, rather like the camshaft on a four-stroke engine. The volume of ach chamber changes as the rotor pins round so the fuel/air charge can sucked in through a port in the wall he oval chamber, in the manner of o-stroke. In the second part of the ber, the charge is ignited and finally sts through a port, again two-stroke e engine burns the air/fuel mix then haft and power is produced: truly eering.
Wankel advocates play some interesting political games with a rotary engine’s size. When it suits them, they will claim that the capacity of a Wankel is represented by the internal volume of one of the rotor’s segments. In the case of the RE-5, this is 497cc. However, no-one was ever going to pay big bike money for a 497cc engine so Suzuki claimed that the RE-5 was actually a 1000cc multi. I could never quite follow this logic, even if it was demanded by some regulatory authorities. If the capacity of the whole engine was to be measured then surely it should have been a 1491cc triple rather than a 994cc twin? I think the reason that it wasn’t so branded was purely a marketing one. A 1500cc bike producing only 67bhp and a feeble 55ft/lb of torque was a guaranteed sales failure before it ever reached the showroom. Why then not sell it as a hot-performing 497cc single? The problem here was the price point. In the crucial American market, at $2475 the RE-5 was almost 30% more expensive than the stunning Kawasaki Z1B selling at $1895 – a bike which would slaughter the RE-5 in every single department. Honda’s wonderful CB750K3, a somewhat closer competitor in terms of performance, was a thousand dollars cheaper at only $1495. So before anyone had even ridden an RE-5, Suzuki were boxed into a real ‘cost versus perceived value’ corner. Like a lot of internal combustion engines, the Wankel’s origins are German. In 1919, the 17 year old Felix Wankel was pondering how to make a simpler and more efficient engine than the burgeoning two- and four-strokes which were appearing everywhere. The problem was that the young Felix’s dreams were far ahead of the available technology. Regardless, he obtained his initial patent in 1929, but it was 28 years later, in 1957, that a practical rotary engine was first produced by the German NSU concern. On paper, the engine is a delight. There are no four-stroke valves boinging up and down and a complete absence of two-stroke disc-valves whirring round and round. In fact, with only one moving part, the Wankel engine is a wonder of simplicity and engineering elegance.
Except that it isn’t. The problems are manifold and serious too.
First, the tips of the rotors have to seal perfectly on the combustion chamber – and at high speeds too. To achieve this seal, there is a spring-loaded tip on the end of each arm of the rotor. These tips have to make perfect contact with the combustion chamber and so have to be extremely hard and durable. Clearly, the combustion chamber’s surface has to be hard too and this is difficult to achieve. In Suzuki’s case, the solution was to purchase the coating technology from the US firm Platecraft – and this wasn’t cheap.
Despite the apparent simplicity of the rotary engine, it’s not efficient – particularly at lower rpm. To get the RE-5 to make reasonable torque, Suzuki designed a combustion chamber with multiple ports to mimic the boost ports which they knew all too well from the two-stroke technology they had ‘borrowed’ from MZ in 1961. However, boost ports weren’t sufficient on their own and Mikuni were commissioned to produce a unique two-stage carburettor which choked the available fuel at low rpm and then made more available as the revs increased. Simple engines? No, not really.
Then there was the major issue of the heat generated during the Wankel cycle. Rotary
engines run hot – incredibly so – which is why the RE-5 was made to be water- and oil-cooled from the outset. A further issue with water cooling a motorcycle engine and then putting it into an unfaired bike is that, aesthetically, it looks like a generator or car powerplant.
Not that the challenges finished there. The exhaust gases produced by the RE-5 were so hot that a double skinned exhaust had to be used – and even then this had to be force fed with air, via two ducts at the front of the bike.
As the engine got nearer to production, Suzuki increasingly found that Wankel simplicity did not equate to conventional engineering simplicity. Three separate oiling systems were needed to make the engine reliable. One was total loss, for the rotor tips, and this was an immediate cause for concern because the first glimmers of the rising environmental impact sun were starting to be seen on the horizon. A second, completely separate, lubrication system looked after the main bearings while a third lubed the gearbox. In order to operate the dual stage carburettor and the lubrication system, a total of five separate cables had to be opened and closed by the throttle. How simple do you want simple to be?
The final result of the engineering was a hugely complex motorcycle which was expensive to produce and didn’t stack up in terms of performance. Could things get any worse? Actually, yes they could.
It’s important to stress the social and historical context of Suzuki’s Wankel. When project chief Shigeyasu Kamiya launched the RE-5 programme, both Honda and Yamaha were also actively developing Wankels of their own. In fact, Yamaha got as far as producing the first batch of tooling for a twin rotor design. At the launch, Jitsujiro Suzuki, president of the Suzuki Motor Company, had the light truly shining in his eyes when he
said: ‘Our success in realising the RE-5 would have not have been possible without the strong pioneer spirit that has characterised Suzuki since its establishment. But just as much, it relies on our motto: To Make Products of Value.
‘More than an adventure in advanced technology, the Suzuki RE-5 faithfully reflects our wish to respond to the needs of the user, in terms of operational performance and comfort.’
The Suzuki PR staff were just as evangelical. ‘ The RE-5 is confirmation that the several advantages of the rotary type internal combustion engine – smoothness in operation, low vibration, a small number of moving parts greatly reducing maintenance problems…’
And so the eulogy went on and on in the way which only true missionaries can. Oh dear. In Britain, the BSA group had already committed to a twin rotor Wankel as their saviour for the future. In every way, the signposts were pointing towards a rotating future. For their part, Suzuki put the necessary millions of dollars, in terms of engineering and capital investment, to make the RE-5 a success. A brand-new, unique production line was built at Hamamatsu. Mr Kamiya then brought in the world-leading Italian stylist Giorgetto Giugiaro to give the highest of high tech looks to the bike. Giugiaro had the instrument panels covered by a translucent, green cover which rolled back, Star Trek style, to reveal – well, a pair of very ordinary analogue clocks.
Then customers got their hands on the bike…
The RE-5 launch was fronted by American astronaut, Ed Mitchell, who extolled the virtues of this cutting edge motorcycle. However, engine apart, the bike actually wasn’t that advanced. The gearbox was lifted from the Suzuki GT750 triple and was only a five-speeder, and the very conventional chassis struggled to deal with the problem of the huge, heavy lump of an engine which had to be mounted very high in the frame. Suzuki gave the bike a long, 59” wheelbase to add stability, which it did, but this accentuated the bike’s already porky size even more.
Suzuki dealers worldwide were told to go flat out with their own consumer launches. Martin Crooks was then a fourteen year-old who worked after school in his dad’s CrooksSuzuki dealership – at the time the biggest Suzuki franchise in Britain. Martin remembers the launch well. Eddie, his father, hired the Civic Hall in Barrow where ‘we showed off the RE-5 which Suzuki told us we had to stock. There was loads of interest but no-one wanted to part with their own money. Eddie was keen on the RE-5 because he’d already
owned a Wankel-engined NSU car, but even with his enthusiasm, he couldn’t convince customers to buy it. Eventually, we got rid of the one bike and we were glad to see it go.
‘We had a whole board full of Suzuki special tools which I wish I still had but they all got destroyed in a fire, so we really never did make any profit from the RE-5 project.’
Despite all the glitz and glamour of a very posh launch, the RE-5 was a sales disaster. Crooks-Suzuki were not the only ones to hit a concrete wall in terms of sales. Only 65 RE-5s were sold in the crucial German market during 1975 and, as the bike’s reputation developed, this fell to one – as in a single unit – in 1976.
If the RE-5 was a complex beast in the hands of Suzuki development staff, it proved to be plutonium toxic for normal customers. A key problem was the unique NGK A9EFP spark plug. This had a fondness for oiling up, at which point the bike wouldn’t start, and replacement plugs were difficult to obtain and expensive. Then there was the issue of getting all five cables correctly adjusted and keeping a close eye on the three separate oil reservoirs.
But none of these issues was the deal breaker in the bike’s success or, as things transpired, its failure. I have met a few Wankel engineers over the years and they all make one crucial mistake. It is to assume that while rotary engine technology will develop, four-stroke designs will remain static. While Suzuki were ram-raiding their cash reserves for the RE-5 project, they were also developing the truly delightful four cylinder, four-stroke GS750. This bike produced 72bhp compared with the 67bhp of the RE-5, made more torque, weighed slightly less and sold at $2195 – almost 10% cheaper than the Wankel.
The GS750 also handled vastly better than the RE-5 and could be ridden ruthlessly, flat out, all day every day without missing a beat. Suzuki dealers were soon queuing up for the new inline four, and desperately trying to bury any RE-5s they had in stock by doing ridiculous deals. A chap I knew actually swapped a suit of replica medieval armour, and not a very good one either, for an RE-5 – and then immediately regretted the deal. I rode his bike for a couple of hours in 1977 and my overwhelming memory was of wasting a nice afternoon, when I could have been doing something which was much more fun.
The only thing of interest was the very attractive burbling Wankel note – always unmistakable if you have ridden a
rotary-engined motorcycle. The rest of the experience was memorable for its dullness. There wasn’t much power, and the bike’s owner had given me severe warnings about the dangers of over-revving the motor, while the handling continued the theme of utter ordinariness.
Would anyone pay a premium to own a bike like this, even it were the best looking and most reliable motorcycle ever made? The answer was unequivocally in the negative.
Yet today, and in the weird way of the classic world, the RE-5 attracts near fanatical loyalty from its acolytes in the way that quirky motorcycles tend to do. For some brave souls, willing to experiment with an extended test ride and prepared to lavish attention on its unusual engineering, the RE-5 has become an engaging alternative to the usual UJM. They even have a support group, in the shape of the Rotary Owners’ Club…