Gilera Motorcycles and Racing History

GILERA MOTORCYCLES
AND
RACING HISTORY

By Lucien C. Ducret​

Guiseppe Gilera who was born in 1887 started at the age of 15 an apprenticeship with the Bianchi motorcycle company as a mechanic, he went on to further his skill with the Italian branch of the Swiss Moto Reve company including a stage at the factory in Geneva. At the age of 22 in 1909 Guiseppe Gilera built the first motorcycle of his own design in a small shop in Milan. He won the same year a hill-climbing race with this machine. In 1911 he started a modest Gilera racing team and participated in many regional races. Starting to get recognition he met a lawyer who had chronic trouble with his Harley-Davidson; Gilera’s magic hands cured the problem. The lawyer was so impressed that he introduced Guiseppe to wealthy investors who financed a start up company manufacturing of a side valve single motorcycle followed by a twin.

Expansion necessitated a move to Arcore outside Milan. As the business expanded Guiseppe Gilera relied more and more on his family to fill key position. He was also very generous with his employee giving interest free loans and bonuses to built houses in Arcore, earning him a loyal following. In the early 1920’s the racing machines were nothing more than modified street motorcycles until 1924 when a racing push rod O.H.V. was built, this model had a lack luster career, only in 1930 after many modifications did this motorcycle won the International Trophy in Grenoble in the hands of the Gilera team and again in 1931.

As business became profitable the next few years saw very few involvement with racing, however as Mussolini ascended to power he wanted to use involvement in international racing as a political statement henceforth recommending all manufacturers to produce winning racing machines. As luck would have it at the end 1935 Gilera was offered a deal to buy the supercharged 4 cylinders Rondine racers acquired by the Caproni Aircraft company and immediately foresaw their image building potential.

ORIGIN OF THE FAMOUS GILERA
TRANVERSE FOUR-CYLINDER ENGINE

In the early 1920’s two young engineers, Carlo Gianini and Piero Remor came up with the idea of designing a four cylinder engine placed across the frame to alleviate the cooling problems associated with in line four.  With the help of a wealthy businessman Count Bonmartini they started a company named GRB. Their first 490cc engine produced 28 Hp. at 6000 rpm. The company expanded and was renamed OPRA after more capital was found with the addition of a new partner Count Lancelotti. A frame was built and a rider-engineer named Piero Taruffi joined the firm to test the new motorcycle, by 1928 the engine developed 34-hp. witch was at least 10 hp. more than the engines of the period.  This motorcycle was entered in many races but due to insufficient development work and despite greater top speed ended up with malfunctioning or blown engine.

Bonmartini offered to sell the motorcycle but there where no takers. In the early 1930’s Bonmartini started an aircraft factory named C.N.A. after some disagreement the temperamental engineer Remor left. In 1933 the racing motorcycle design was completely redesigned with Gianini as the project engineer and Taruffi as assistant. The new motorcycle was named Rondine, had water-cooled cylinders and was equipped with a supercharger producing 60hp at 8500 rpm.  In 1935 the Rondine finished 1-2 at the Tripoli race in May, however 3 Rondine made a poor showing against the Guzzi team in the Monza race in November.

Few months later with a fairing Taruffi broke the world record on the flying km / mile at 152 mph. In the 500cc. Class. At about this time Bonmartini decided to retire and sold is business to the Caproni aircraft Company including the Rondine motorcycle package. In 1936 Caproni instructed Taruffi to sell the Rondine racers. Taruffi contacted Giuseppe Gilera that readily bought the package with the condition that Taruffi would join the Gilera Company.

Guiseppe Gilera was a talented mechanics but also a tough businessman and foresaw the great marketing impact that a successful racing team would have on the sales of his street motorcycles. He ordered Taruffi to get rid of the reliability problems of the racers, particular attention was given to crankshaft bearings fragility, the problem was solved and modifications were made to the frame and blower.

The Gilera four was campaigned all over the European racing circuit with the final crowning achievement of beating the BMW in 1939. Taruffi went on to break fifty world speed records attaining 170 mph on the flying kilometer on a specially prepared Gilera 4, producing a claimed 70 hp. at 8800 rpm. World war II interrupted all activities that finally resumed in 1946 with the Swiss GP held in Geneva.  As a kid I still remember going to this race with my uncle.  The fierce Omobono Tenni had problems with his Guzzi and stopped right in front of us to change his spark plug.  I still can picture him burning his fingers while replacing the plug and than sticking the wrench in his boot before taking off like a Devil.  Tenni at the age of 43 was later killed at the Bern GP in 1948.

Superchargers were banned on motorcycle in 1946. The Rondines were modified to run with carburetors but were down on power and outdated, for all practical purpose their glories days were over.  Taruffi had rehired Engineer Remor in 1940 to work on the next generation of 500cc racers but instead worked in the interim on a 250cc. 4 cylinders supercharged air-cooled engine. In 1946 Taruffi left to concentrate on car racing. In 1947 Remor with Guiseppe Gilera turned their attention to the 500cc. racer, the final engine design bore a striking resemblance to the 1940 250cc. engine that was built but never raced.

The new 500cc. racer was unveiled in the spring of 1948, compared to the Rondine it was a slick design, weighting only 275 lbs, the pressed steel girder fork was retained, but every thing else was new. The rear suspension was of an unusual design using torsion bar and friction dampers. The Gilera was raced at the Dutch TT in June where prominent Japanese manufacturing representatives took numerous rolls of film of the new racer. The 1949 season was a shake down for the new bike and went on to demonstrate its potential by winning several races but failed to win the manufacturer title that was clinched by one point by Les Graham on AJS.

At the end of the season the temperamental Remor quit Gilera to join MV Agusta possibly over his desire to share into the Company’s profits. According to Masserini, Remor’s reputation was overblown and in fact the design of the transverse 4-cylinder engine should go to the creative Gianini, and hands on engineer Taruffi. Remor was primarily a mathematician unable sometimes to solve practical problems such as when a lubrication defect caused the engine to blow up, the problem was solved by Colombo his assistant. He had connections with the technical department of Alfa Romeo and apparently borrowed some of their design solutions. Before leaving Gilera, Remor pocketed a set of blue prints showing the next phase of design improvements. When the first MV Agusta Racer was shown in the spring of 1950 it displayed an uncanny resemblance to the Gilera racer to the dismay of Guiseppe Gilera.

Taruffi was rehired and the boss promoted Colombo and Passoni from within to reward loyalty and prevent dissemination of the engine’s secrets.  For the 1950 season the design improvements included discarding Remor’s rear suspension and reworking the engine’s head. Masetti went on to win the 500cc. World’s championship with the revised Gilera racer.

In the winter of 1950-1951 Passoni decided to completely revise the frame by adopting a new tubular design with telescopic fork and a pivoting rear suspension with hydraulic shocks.  1951 saw 3 GP victories but the title went to the talented Norton rider Geoff Duke.  In 1952 Masetti again secured the World title. For the first time 2 multis went to foreign racers Georges and Pierre Monneret of the Gilera Agency in France.  The Assen Dutch GP saw Masetti and Duke fighting for the lead during the entire race, only to see Masetti overpowering Duke at the finishing line. The season ended with Masetti regaining his title Taruffi finally broke the rule of using only Italians for the racing team and recruited Reg Armstrong and Dickie Dale. Taruffi masterstroke was played when he signed one of the greatest riders, Geoff Duke which had been sidelined by Norton. This action would insure the complete domination of the Gilera team for many years to come.

Duke made many suggestions to improve the handling of the bike, mainly the frame was lowered and strengthened in order to attempt to duplicate the Norton handling, the engine was left untouched. Duke won the 1953 world 500cc championship and Gilera won the manufacturer title for the second year in a row.

During the winter of 1953-54 Passoni completely redesigned the engine increasing the stroke, changing the valves angle and elongating the sump pump allowing the engine to be lowered reducing the bikes height by 3 inches. Passoni’s engine now produced 64-hp at 10,500 rpm.

The 1954 season was a repeat of 1953 with Duke completely dominating the field. I saw Georges Monneret racing the awesome Gilera multi in the French national race of Clermond Ferrand in 1954 where the show of power was so incredible that Monneret so to speak ran circles around the competition.

During the Dutch TT in 1955 Duke sided with the privateers witch rightly asked for more starting money and consequently was banned to race in two important GP by the mercurial F.I.M. Motor racing has been always extremely popular in Europe drawing as many as 500,000 people for one GP. The organization would collect huge sums of money while the privateers risked their lives for glory and few crumbs.

Duke collected his third World championship in 1955 aboard the fearsome Gilera multi. With such dominance by the Gilera team, Taruffi decided to retire and hand over the manager position to Ferrucio Gilera, the son of Guiseppe Gilera.  Passoni revised the racers again for the 1956 season, introducing a new dustbin fairing, strengthening the frame and increasing the power to 70 Hp. The handicap caused by the F.I.M ban, added to mechanical failure while leading several races, prevented Duke from winning the title, which went instead to Surtees on the MV.

In 1957 Guiseppe’s only son, Ferrucio had a heart attack.  This untimely death caused Guiseppe to loose interest in his business and racing.  The 1957 season began and Duke’s new dustbin fairing required changes in the frame.  His request fell on deaf ears; the racing department had lost its motivation.  During the first race at Imola, Duke and other racers fell, victims of the poor track surface. Duke injured his shoulder and had to miss several races while convalescing. The highlight of the season came when McIntyre broke the magic ton four times in the famous eight-lap Golden Jubilee Senior TT. The last race in Monza saw Libero Liberati confirming his championship title with Duke second and Milani third.  Gilera again finished the season with the coveted manufacturer’s title safely in hand.

As Passoni was getting ready for the 1958 season with new improvements, Guiseppe Gilera pulled the plug, after nearly 50 years of successful racing involvement he decided this was enough and announced the Gilera withdrawal from racing for three seasons. Guzzi and Mondial joined the withdrawal leaving the field clear for MV, Ducati and Morini.  Credit must be given to all the great Gilera 4 riders such as Taruffi, Serafini, Aldrighetti, Pagani, Bandirola, Masserini, Artesiani, Masetti, Liberati, Milani, Colnago, Dale, Armstrong and Duke who made this era such a fascinating one.

Reflecting on Gilera’s tremendous racing successes with the transverse four cylinder engines it is amazing to think that that Gilera never entertained the prospect of creating a road machine based on this design. Cost was certainly a factor but a latent worldwide demand for such a machine existed as shown by the success of the Japanese manufacturers.  Millions of bikes were sold based on the design of the Gilera racer. I own a 1977 Honda CB400F and while dismantling the engine to repair a frozen valve (due to 10 years of inaction) I had to marvel at the quality of the craftsmanship and the beauty and elegance of the design. Guiseppe this could have been yours…….

GILERA 500cc SINGLE CYLINDER RACING SATURNO

The first prototype of the Saturno racing version equipped with a 32 mm. Dell’Orto carburetor was shown on 1940 and Massimo Masserini won the Targa Florio in Palermo on its first race with it. The privateers instantly recognized the potential of this machine.  After the ban on superchargers in 1946, the Saturno racing version was hastily revised as a stopgap measure because the new 4-cylinder machine was not yet ready. The Saturno now featured a blade girder fork and a full width front brake; a 35-mm. carburetor was installed to boost power to 36-hp at 6000 rpm. Raced to first place in 1947 and 1948 by Carlo Bandirola in San Remo, the Sanremo name stuck to this motorcycle model. The Saturno won this race for the next three consecutive years.

This racing machine (the San Remo) was again up-dated in the winter of 1950-1951 with bigger cylinder barrel fins and head, larger sump and telescopic fork.  Nello Pagani gave the Saturno a well-deserved growing reputation by winning the Spanish Montjuich Park GP in 1950.

In 1952 a new tubular frame was designed using telescopic rear suspension, wheel rims were reduced to 19 inches. Power was increased to 38Hp. at 6000 rpm. This new model was renamed Piuma (feather) Good for 120 MPH.  Final revision was made in 1955 increasing the Dell’Orto carburetor to 38 mm. giving 42-hp at 6500 rpm. With a dustbin fairing speed increased to 130 mph.  The racing Saturno was extremely well suited for circuit with a lot of turns and shorter straightway since the Saturno engine had a lot of torque and would give great acceleration after a turn but could not compete in top speed against the Gilera multis, despite this handicap the Saturno gave the multis a run for their money as it did in 1951 at the Barcelona GP in the hands of Alfredo Milani building a great lead over Masetti on the Gilera 4 only to retire with valve problem. The Sanremo placed well in many international races until the Multis that were given top priority in the racing shop became too powerful, however the Saturnos were campaigned successfully in national races such as with Libero Liberati in Italy and Houel in France.​

Gilera’s racing shop was headed by Luigi Gilera, the brother of Guiseppe, built as many as 20 Saturno racers a year throughout the fifties for sale to privateers.  Modified versions of these bikes were still competing in the sixties.  In 1951 Luigi Gilera was pestering Passoni to design a new Saturno twin-cam racer.  With limited time and funds available it was not until 1952 that Passoni got to it. The new engine produced a healthy 45-hp at 8000-rpm using a 38mm Dell’Orto carburetor. The right distribution side of the engine looked massive and fearsome. Only two units were built and were entered in several races in 1953.  However, with lack of development they were plagued with mechanical problems and had to retire. Only Georges Monneret managed to win a race in Bordeaux with the twin-cam. With Duke and the Gilera 4 doing so well, the twin-cam Saturno version became a superfluous money drain. Consequently the two machines were ordered destroyed, by chance or by design one of the two engines managed to escape it’s rendezvous with the crusher.

SATURNO’S RACING SIDECARS OUTFITS

In 1946 and 1947 the Gilera Saturno sidecars won all the Swiss and Italian National races, in 1948 Norton started to offer stiff resistance. In 1949 the Saturno engine was bored out to 582cc. The Saturno outfit went on to win many races but the tactical genius of Oliver on Norton precluded the win of any GP championship, the Italian championship was a different story when the Saturnos won in 1949, 1950, 1951, 1952 and 1954.

GILERA 500 cc SATURNO RACING ENGINE
ADDITIONAL TECHNICAL INFORMATION​

The overhead valves are set at 70 degree with rocker arms activated by 6mm rods terminated by a blind threaded hex nut secured by a jam nut both used to adjust the valve clearance.  Intake valve as a 45mm O.D. and the exhaust valve has the same diameter valve guides are made of bronze and valve springs are of the hairpin style. Valve lifting is 10mm. The aluminum head is hemispheric.

The Dell’Orto monobloc carburetor as a 35mm I.D. and is of the down draft type (enlarged to 38mm in 1955).  The exhaust pipe has a 45mm. I.D. (after 1955 enlarged to 50mm.)  The engine crankshaft is spinning on 3 bearings, one roller bearing on the primary drive next to the crankshaft with a ball bearing supporting the end of the primary gear shaft pressed in the primary drive aluminum cover. The third bearing is a ball bearing supporting the crankshaft on the distribution side. The rod big end is fitted with double roller bearings.

Linear speed of the piston is 18 m/sec at 6000 R.P.M. The aluminum cylinder is fitted with a cast iron sleeve, the large aluminum head is bolted to the engine block with 5 pulling studs featuring differential threads to insure maximum holding strength since the head is designed with  5 blind threaded holes.

The 5 main studs have a hex lower portion with an internal thread fitting over permanently attached threaded studs affixed to the engine block. With the cylinder in place the 5 main studs are threaded home after the head is placed over the tip of the studs, incrementally and sequentially the studs are threaded into the head until tight and finally torque to the proper ft/lbs.

The capacity of the engine sump is 2.5 liter of Castrol R oil. The 4-speed gearbox has sliding gears with cogs. The speed selection is made with a system of cams and ratchet gear actuated by a double-ended heel and toe gear change lever.  The swing arm rear suspension is pivoting on bronze bushings.

OTHER CHARACTERISTICS

The engine block is designed to have all the internals removed except the crankshaft without removing the engine from the frame.  Better running of the engine is obtained by inserting a 10mm Phenolic spacer between the carburetor and the head; a 90mm long conical air intake velocity stack improves efficiency.  The breather must have an 18mm. opening.  Spark plug recommended are KLG-FE80 three electrodes for sport driving and LODGE R-51 Platinum with long thread for racing.

The Gilera Saturno was shown for the first time at the Milan show in 1938, the single unit engine designed by Guiseppe Salmaggi was a departure from the norm of the day. Despite its clean lines all the components were easily removable except the crank-shaft without taking the engine out of the frame.

During World War II the Italian Army used many modified Saturno’s. After the hostilities the Saturno road machine was equipped with a girder fork in conjunction with an unusual rear suspension designed by Guiseppe Gilera in 1934 comprising vertical levers compressing horizontal springs enclosed in tubes integrated in the frame, the back of these tubes had an other set of springs for rebound damping, a set of adjustable friction dampers were connected between the rear fork end the back of the tubes containing the springs. This was quite a sophisticated design since most of the motorcycles of the time had hard tail. This rear suspension was used until 1952. During 1951 a telescopic unit replaced the girder fork. The telescopic rear suspension was introduced in 1953 with a complete new tubular frame.

At the risk of sounding biased, I believe that the Gilera Saturno Sport built in 1953 until 1958 with the elongated double seat and the large tank is probably the best looking classic motorcycle of the after World War II era, marrying sensuous form and function in the Italian legacy of Da Vinci. The Italian craftsmen of large machines (500 cc. was considered large in Europe and specially in Italy) did not think in term of mass marketing or cost cutting, but trying to make a timeless statement. The Saturno engine for instance is a masterpiece of engineering, highly polished aluminum castings hide and seal most of the components such as oil tank (wet sump), oil filter, oil pump, gearbox, totally enclosed primary gear drive. The massive elaborate aluminum head encloses the valves with the hairpin springs and the rocker arms actuated by unusual thin pushrods are guided by bushings installed in a passage in the cylinder barrel. The lubrication of the engine is internal with absolutely no external plumbing. The only exposed separate components are the Marelli magneto and dynamo and of course the carburetor with the gas lines.

The complete package is in two words elegant and beautiful in its simplicity. One would ask why then didn’t the Gilera Saturno take the world by storm! The answer is two fold, first Guiseppe Gilera was primarily involved with the Italian market, which because of the tax scale on motor vehicles, drove customers to purchase mainly 125cc. and 175cc. motorcycles, secondly except for the factory in Argentina Gilera had very few dedicated worldwide agencies. An endemic problem with the factory was the availability of spare parts and marketing support of Agencies. I owned a 1949 Saturno in Geneva Switzerland, after an unfortunate encounter with a car in 1952 my front fork was totally wrecked, it took 4 months to get the parts from the factory.   Inasmuch as the 125cc Gilera was very popular in Geneva at that time, I knew of only 4 Saturnos including mine in a city of 200,000 people. However the 250cc & 500cc.Moto Guzzi Falcone were everywhere because of the very aggressive marketing of the Swiss Guzzi Agency. 

In 1953 my good friend who was riding his father’s motorcycle was ready to get his own, he liked my Saturno a lot and I decided to show him the latest model sitting in the window display of a motorcycle shop. This new model had the telescopic front fork and the telescopic rear suspension, the bulbous gas tank and the double seat, he fell in love with it instantly. After discussing the price with the salesmen he whipped up cash from his pocket and bought it on the spot, I was quite impressed!   While vacationing in Italy with my Saturno friend and another riding a Norton twin, we were surprised to see a crowd of men circling the machines. Where ever we would stop and we got asked all kind of questions, fortunately my Norton friend spoke Italian.  At that time in Italy the prominent mode of transportation were scooters and small motorcycles.

On our way back north I convinced my friends to stop at the Arcore Gilera factory near Milan since I needed spare parts. A men at the gate told us this was not a kid’s nursery and couldn’t let us in. That’s where my friend fluency in Italian came into play buttering him up and explaining how impossible it was to get parts in Switzerland, not to mention all the Lira I would part with. He finally relented and let me go to the stock room were luckily I got all the parts that I requested.

We made an impromptu stop at the Monza racetrack where for a fee we could go few laps around the track; we promptly removed our mufflers and went flat out on the track. Having a Sanremo engine I quickly lost sight of my friends, the feeling was especially terrific since beside my helmet I was wearing only a pair of short and sandals! Everything went well until a rabbit crossed the track which I fortunately missed by a couple of inches, reminding me to close the throttle slightly before the next turn. The next turn never came because I ended up in what looked like a huge parking lot, not knowing where to go I frantically stepped on the brakes and ended up on the grass. I came back to the first corner and saw the tire marks showing the line to take. This was a good lesson in taking it easy until you learn the ins and outs of a track!