500cc Grand Prix machines

Posted on by admin

Menus

500cc Grand Prix machines

Royal children

The road world championship is celebrating its birthday: 50 years ago the first race started on the Isle of Man. A foray through the technology of the 500 top class shows how rapidly the machines developed.

A good 50 hp, these days they don’t knock anyone off their feet. Almost every series enduro can do that much. But 50 years ago this performance was the measure of all things in the 500 top class. And it can be assumed that the stars of those days, despite the relatively modest power of their four-stroke engines, got a similar kick while driving as Doohan, Biaggi or Criville do today on their 200-hp rockets. Because the chassis of the machines were miles away from today’s standards, and the riders had to beat their bikes on street courses where safety was an absolute foreign word: ditches at the edge instead of gravel beds, trees, hedges or even walls instead of modern airfences.
The first round of the Motorcycle Road World Championship started on June 17, 1949 on the Isle of Man. The victorious Norton rider Harold Daniell was in the saddle for three hours and achieved an average speed of almost 140 km / h on the infamous mountain course. Bern-Bremgarten, Assen, Spa-Francorchamps and Ulster were the other stops of the season. The first 500cc road world champion in motorcycle history was finally crowned in Monza: Leslie Graham (England) on AJS.
Half a century later, a very special meeting took place on the traditional Monza train at the gates of Milan. On the occasion of the World Cup anniversary, MOTORRAD assembled almost a dozen historic 500cc machines from different decades as well as some drivers and technicians. Moto Guzzi brought a single-cylinder machine and the spectacular eight-cylinder racer from the 50s. Willi Marewski, a passionate motorcycle collector from Frankfurt, contributed a BMW RS 54, a Norton Manx and an MV Agusta from 1962 and 1974. The legendary three-cylinder MV, with which Giacomo Agostini once produced victories and world championship titles on the assembly line, was just as present as Yamaha and Suzuki bikes from the 80s or a Gilera from 1954.
Gilera had been a successful racing driver before World War II. In 1939 Dario Serafini won the European championship on the Rondine with a water-cooled inline four-cylinder and supercharging. For the world championship, designer Piero Remor developed a similar concept: an in-line four-cylinder with two overhead camshafts, but this time air-cooled and, according to the regulations, without a compressor. In 1949 Gilera had to bow to the British competition from AJS, but the following year Umberto Masetti gave the factory from Arcore near Monza its first triumph. Another title for Masetti followed in 1952. Between 1953 and 1955, the combination of Gilera and Geoff Duke was unbeatable in the half-liter class.
Moto Guzzi relied on a single-cylinder engine at that time. But in the 500 World Cup, the single didn’t make a trick, in contrast to the 350 class, which Guzzi almost dominated. In 1956, the factory emerged with a technical sensation: a 500cc machine with a V8 engine. While the spectacular multi-cylinder was able to celebrate successes in free races, the defect devil usually struck in the World Championship. At the end of 1957, Moto Guzzi finally retired from the sport.
In the same year Gilera shut down the racing department. But the concept devised by Piero Remor was still successful, only in a different packaging. The Italian Count Agusta had recruited the successful designer for his new racing team in the early 1950s, so it was not surprising that the MV Agusta four-cylinder engines looked astonishingly similar to the Gilera engines. In 1956, the young Briton John Surtees struck for MV for the first time, and after Gilera withdrew, the way was finally free for the red racers. John Surtees, Gary Hocking and Mike Hailwood raced with the four-cylinder two-valve engine to nine 500cc world championships by 1965 – no engine was ever more successful in the premier class.
MOTORRAD tester and ex-racing driver Siggi Guttner was able to explain the superiority of the MV well after a few trial laps in Monza. “It’s as easy to handle as a bicycle,” he enthused about the qualities of the 1962 MV, which has nothing in common with a capricious, difficult-to-control racing motorcycle, neither in terms of handling nor power delivery.
A German driver also made a name for himself in the Surtee era: Walter Zeller. He won the 500 runner-up world championship in 1956 with a factory-supported BMW. The Munich boxer was also attractive to private drivers. As early as 1954, BMW had built 24 copies of the RS, an exact copy of the factory machine, and sold it to handpicked customers. The piece cost 6,500 marks – at that time roughly the equivalent of two VW Beetles.
Ernst Hiller had one of those. In Monza he celebrated a reunion with one of those production racers that he had successfully driven between 1956 and 1962, although he lacked around 20 horses on the 75 hp MV with the BMW. He proudly presents a photo album that shows him at the 1958 Grand Prix in Assen on the BMW in the front row next to John Surtees. After all, he was fourth at the finish. Ernst Hiller achieved victories in international road races and three German championships with the boxer machine, the chassis of which was considered stubborn. “Many couldn’t get along with the BMW, but I won my first race with it,” recalls the now 70-year-old from near Bielefeld. “You couldn’t touch the handlebars too hard, a sensitive driver was required for this motorcycle.”
The Norton Manx was also very popular with the privateers of that era. The commercial version of the factory machine with which Geoff Duke won his first world title in 1951 was also available for 6500 marks in the 50s. Its plus was the excellent road holding – thanks to the so-called feather bed frame designed by Rex McCandless. The big hit with the double-cam stew was the long-running favorite: up until 1964, private Norton drivers repeatedly managed to get into the top three of the 500 World Championship in the final accounts.
At that time, however, the brand that has remained the epitome of Italian Grand Prix motorcycles to this day was still dominant: MV Agusta. However, the Italians had a strong headwind from Honda in the mid-1960s, which led company boss Agusta to have a new engine built. The then MV race director Arturo Magni, now 73, remembers the history of the development of the three-cylinder engine, which began in 1964 for the 350 class because Honda had since taken over the command there. “The Conte Agusta simply gave the order to develop a three-cylinder engine,” says Magni. “We were finished in just a few months and brought the motorcycle to the Lido island of Venice, where the count was on vacation. He was satisfied with our design, but made it a condition that the machine was driven by an Italian. “
Giacomo Agostini was the chosen one. The combination of Ago and MV three-cylinder won seven 500 titles in a row between 1966 and 1972 – no driver has been able to beat this record series so far. The three-cylinder MV, almost as slim and handy as a 250, has remained Arturo Magnis’ favorite motorcycle to this day – and he is still proud of it: “We got a top speed of up to 298 km / h out of 85 hp, that’s a guarantee . “
The last stage of development was then ignited for the 1973 season. In the early 1970s, MV had come under renewed pressure in the 350 class from the water-cooled two-cylinder two-stroke engines from Yamaha and Aermacchi under riders like Phil Read, Jarno Saarinen and Renzo Pasolini. Reason enough to develop a new engine again. As early as 1971, a filigree inline four-cylinder with two overhead camshafts and four valves per cylinder, which turned up to 16,000 rpm. In 1973 both displacement variants were finally ready for use and immediately won both titles. The 500 crown went to MV newcomer Phil Read, who had disrespected the previous top dog Giacomo Agostini.
Agos Liason with MV came to an end for the time being, but the train in Grand Prix racing after Read’s second 500 title had also left for the factory. The two-stroke engines now also took command in the premier class (see also box “World Cup Chronicle”).
And it was Ago of all people who immortalized himself in the chronicle of the 500 World Championship as the first champion with a two-stroke engine: in 1975 he triumphed on a four-cylinder Yamaha. At the end of this decade, Yamaha’s high-flyer was Kenny Roberts, and a replica of his world champion machine with the inline four-cylinder was available for 45,000 marks. This motorcycle is a good example of chassis development. The rear swing arm is no longer supported by the classic principle with two struts on the frame, but Yamaha used the so-called cantilever system. A triangular rocker arm is linked to the steering head at the front by means of a single spring strut lying lengthways under the tank.
At the beginning of the 1980s, Suzuki was already one step further with its full floater system. This term hides the monoshock suspension, which has long since become standard, with a central shock absorber and rocker arms. In terms of engine layout, Suzuki had an interesting solution to offer at the time: In the so-called Square Four unit, the four cylinders with rotary valve inlet were arranged in a square.
The journey through time through 500 racing history shows that a lot has changed around the extremely powerful engines (see graphic on page 86). The massive drum brakes were replaced by modern disc brakes in the early 1970s. In the second half of the 1970s, treadless slicks replaced treaded roof tires with extremely pointed contours and a large contact surface in an inclined position, but wobbly handling and poor straight-line stability. Since 1981 steel frames have been out and aluminum chassis with ever thicker profiles have been in. Fairings, driver’s suits and helmets got more and more color.
But the four-stroke racers of the past have one thing clearly ahead of the modern two-stroke: their incomparable sound. If a Norton M.anx hammering or turning up a MV, then the asphalt trembles. 50 HP is definitely enough for that.

Grand Prix racing machines of the 500cc class: Chronicle – World Championship chronicle

1949 – 1955 Leslie Graham won the first 500cc World Championship on AJS. But the strongest driver in the early stages of the 500cc World Championship was certainly Geoff Duke. The Briton won four titles – one on Norton, three on Gilera – between 1951 and 1955. 1956 – 1960 An Englishman again dominated the World Cup. John Surtees won the 500 crown four times for MV Agusta and also won three titles in the 350 before he switched to auto racing and became Formula 1 world champion in Ferrari in 1964. German highlight of that era: Walter Zeller’s 500cc Vice World Championship in 1956 on the works BMW. 1961 The Rhodesian Gary Hocking continued the successful streak of the MV Agusta four-cylinder. 1962 – 1965 With Mike Hailwood, another Briton was at the handle for MV Agusta. After four titles in a row, he went to Honda, where he was champion several times in the smaller classes. Hailwood later switched to four wheels, won the Formula 2 European Championship for the Surtees racing team in 1972 and advanced to Formula 1. 1966 – 1972 MV Agusta now relied on the more manageable three-cylinder engine and a young Italian as number one driver: Giacomo Agostini. This combination raced to seven 500 World Championship titles in a row – a unprecedented winning streak in Grand Prix history. Honda was still denied the 500 crown, the Japanese withdrew for the time being. 1973 – 1974 The two-stroke engines got stronger and stronger. Above all, Jarno Saarinen on the factory Yamaha hit MV Agusta with two victories in early 1973. But the Finnish high-flyer had a fatal accident in Monza in the 250cc race. Phil Read was the new star at MV and extended the winning streak of the Italian factory for another two years. 1975 Giacomi Agostini, humiliated by Phil Read at MV, struck back and won the World Championship on a Yamaha – making him the first world champion in the premier class on a two-stroke machine. 1976-1977 Agostini returned to MV and wrote racing history again. His victory in the World Cup final at the Nurburgring was the last triumph of a four-stroke engine. In the World Cup, however, the two-stroke engines had long since taken command. In both years the title went to Barry Sheene on the factory Suzuki. 1978 – 1980 A new star had come to the World Cup from the USA: Kenny Roberts. On the works Yamaha with the in-line four-cylinder, he was ahead of the competition for three years. Barry Sheene, Virginio Ferrari and Randy Mamola only stayed in the championship table. Honda started its comeback with the spectacular oval piston four-stroke engine, but without success. 1981 – 1982 Suzuki drove with the Square Four engine and two young Italians on the road to success. In 1981 the title went to Marco Lucchinelli, the following year it was Franco Uncini‘s turn. Honda slowly got going again with a handy three-cylinder two-stroke engine and the young US boy Freddie Spencer. 1983 The rousing duel between Kenny Roberts and Freddie Spencer marked the season. In the end, Spencer was just two points ahead – Honda was finally on target in the premier class. 1984 Roberts successor Eddie Lawson won on the Yamaha, now equipped with a V4 engine, ahead of the Honda Armada. 1985 The season by Freddie Spencer. With the V4 Honda he won another 500 title and also won the 250 World Championship. The American high-flyer only showed weaknesses in the rain: In Hockenheim the winners Christian Sarron (500) and Martin Wimmer (250) made him look pretty old. 1986 – 1989 Three more titles for Eddie Lawson, one for the Australian Wayne Gardner. Freddie Spencer had already disappeared again. 1990 – 1992 Wayne Rainey won the World Championships on the Yamaha three times in a row. A fall and the resulting paraplegia suddenly stopped his career at the 1993 Misano Grand Prix. In 1993, Kevin Schwantz, extremely popular with fans for his wild driving style, won the World Championship for Suzuki. As a result, many injuries prevented the blonde Texan from triumphing again. 1994-1998 Mick Doohan was the figure of 500 for the last five years. But the dream of the sixth title in a row fell through during training for this year’s Jerez Grand Prix, when the Australian had a hard crash and now has to pause for several weeks.

The performance curves of the GP classes

With the exception of the 500 class, engine performance exploded in the mid-1960s, which testifies to the upgrading of Japanese manufacturers. Constructions such as the 125cc five-cylinder Honda with speeds of up to 22,000 / min, water-cooled four-cylinder two-stroke from Yamaha (125/250 cm³) or the legendary six-cylinder Honda (250/350 cm³) spearheaded this development. The withdrawal of the Japanese factories logically resulted in a drastic drop in output. The reduction of the 50s to one cylinder and the 125s and 250s to two caused performance to collapse, as did the later restriction of the 125s to one pot in 1988. The 500s made strong gains in the mid-70s thanks to the two-stroke engine.

The bikes of the 90s

The technology of the premier class has become very clear. V4 two-stroke engines with diaphragm control are the key to success today. These engines meanwhile mobilize up to 200 hp, but pure power has long ceased to be the topic of the designers in the racing departments. It’s much more about bringing the brute power to the ground. Chassis engineers and tire technicians are therefore particularly in demand. To protect the tires, Honda developed the so-called Big Bang engine in the early 1990s. It no longer ignites regularly after a quarter turn of the crankshaft, but Honda reduced the ignition delay to around 25 degrees. The four candles ignite in quick succession in a range that corresponds to about a quarter of a crankshaft revolution. Since the engine now delivers its power in a compressed area, the tire can be spared in the phases in between and does not degrade as quickly during the race. The competition soon adopted the new principle of smoother power delivery, but now it’s time for Honda: command back. At the request of Michael Doohan, who wanted a more aggressive engine again, conventional ignition technology celebrated its comeback. Three brands shaped the 500 World Championship in the 90s. First, Yamaha was on the trigger with Wayne Rainey, then Kevin Schwantz won a title for Suzuki, and since 1994 the champion has been Michael Doohan on Honda. That will change this year, because the reigning world champion is out of action for a few weeks after his Jerez training crash and has no chance of defending his title.

Leave a Reply

Your email address will not be published. Required fields are marked *