Report From Italy
REPORT FROM ITALY
CARLO PERELLI
GOOD NEWS for private riders! Next year, Aermacchi will sell, over the counter, a 125cc two-stroke racer, called the "Golden Wing," together with their highly successful 250cc and 350cc "Golden Wings." Price has not yet been fixed, but a factory spokesman said it will be very "interesting." Derived from the new 125 prepared for the USA and now available also in Europe and other countries, the new model has clean lines and simple, functional and robust structure. And this is really a bonus for privateers, since tuning and maintenance will be very easy,while spare parts, as with the bigger bikes, will be quickly available, at low cost.
Intensive testing at Monza in June, with Alberto Pagani doing the riding, proved that the prototype, with a four-speed gearbox, lapped faster than the best Honda dohc twin and Bultaco (except Torras' which was a special works machine and was furiously driven to the very limit). The debut came sooner than expected in mid-July on the new Zingonia circuit near Bergamo, in the first Italian Senior Championship event of this year. After a very slow start, Pagani made his way quickly through the field to finish a very promising third, behind the Mondial and the Montesa of the Villa brothers (rotary valve two-strokes with eight-speed gearboxes), but well ahead of another strong Montesa and a horde of other machines, including Honda, Bultaco, Motobi, etc. Looking at this new Aermacchi and examining its inner parts, one wonders how the factory two-stroke wizards succeeded in doubling the power of the touring model, taking it from 10 bhp at 6750 rpm to 20 bhp at 9.200 rpm, rated at the rear wheel. In fact, most engine parts are the same, including the crankshaft and its bearings which have withstood the severest tests without failure. In the cylinder ports, in the flat-top piston and in other vital parts of this absolutely orthodox, twostroke there are no secrets to discover!
Bore and stroke are 56 x 50 and compression ratio is 9.7:1; this latter, like the peak revs figure, is surely unimpressive for a racing 125, but it has proved to be all right. Lubrication is by 5 percent petroloil (20:1 ) which is assured to be sufficient, so there is no need of separate lubrication. Light alloy cylinders with different porting are expected to be available to be matched with various expansion chambers in order to obtain the best performance on a particular type of circuit.
Primary drive, now by helical gears on
the right, will be by straight cut gears, to lower mechanical losses and stress on bearings. The multiplate clutch, also on the right, will be reinforced although the present one has given practically no trouble. But the Aermacchi people prefer to be on the safe side on this detail.
A 27mm Dellorto carburetor is used and ignition is by flywheel magneto on the left, with an external HT coil. The present four-speed gearbox will be changed for the series production with a close-ratio five speed, while the factory is experimenting with an overdrive system (like the Kreidler 50cc GP had) to have eight ratios, four pedal and four grip controlled. The frame has a single top tube with the engine mounted beneath it: already slightly modified from the touring type, it will be further strengthened at the rear. Wheels are shod with 2.50-18 tires front and rear. Ceriani suspension and a 200mm Oldani front brake are employed. The fairing, tank, seat and fenders are fiberglass and this has aided in keeping the weight, in running condition, down" to only 176 pounds.
At the same time the new AermacchiHD racer was unveiled, another racing one-to-five appeared on Italian circuits. More exactly it should be written "reappeared" since we are talking of the Gilera dohc twin, born in 1956 but used little, although brilliantly, before being put to rest in 1957, when the Arcore factory abandoned GP racing together with Moto Guzzi and Mondial, only to be exhumed and proving to still be a force. A description is therefore well deserved since it is an interesting, but little known machine, and because it was overshadowed during its short career by the much more famous 350 and 500cc fours.
Technical layout was quite advanced for mid-fifties; the cylinders, timing gear system and frame were similar to the four cylinders. The machine was very slim and low, although it used the orthodox sized 18-inch tires.
The light alloy cylinders (bore and stroke 40 x 49) were inclined 30 degrees with the cam gears between them; the helical springs were completely enclosed, making the engine appear extremely neat — also a result of its compact dimensions.
The left end of the inlet cam drove the dual control breakers for the coil type ignition (with 10mm plugs); wet sump lubrication, six-speed gearbox in unit, and a geared primary drive are also featured. Power is 22 bhp at 12,500 rpm at the rear wheel; of course, one can't compete against the Japanese with these figures, but for Italian racing they are still ok.
Credentials for this model include various wins (among them at Monza and at the Solitude for the German GP) and above all the world records for the standing start kilometer at 78.7 mph and the one hour at 123 mph,both set up at Monza in fall, 1957, immediately before the motorcycle was put to rest. A 175cc version (25 bhp at 11,500 rpm) was also built.
Nowadays in Italy, even if you drive a Ferrari, you make little "impression" (except on the fisc people!), so more and more chaps prefer to ride around astride powerful motorcycles which actually attract quite a lot more attention, beside putting the rider into the "real men" class.
To outshine all the others, a rich Milan merchant is often seen around on a 500cc "Manx," converted to a roadster, and he says that also because of his bump-starts he is more watched now than he was when he used to circulate in a Maserati!
Main modifications to his mount include a slight reduction in compression ratio and different gearbox and final drive ratios to facilitate use in town, plus a longer, closed megaphone for a reasonable exhaust noise level. Top speed is reported to still be around 125 mph! It's interesting to note that many of the people who turned to motorcycles for snob appeal and personal shows gradually have become ardent enthusiasts!
Extravagantly styled 50cc models are always more popular in Italy for "beat" youngsters who are too young or have no money for bigger or "one-off" bikes but
still want something very peculiar. Painted in gay colors (usually too gay), with plenty of chrome, with many head and tail lamps, exaggerated western style bars, crash bars and, since the "mini" custom is now furiously spreading in Italy, with little wheels (10 or 12 inches), these mounts are all powered by two-stroke, four-speed engines of 4 or 4.5 bhp and will therefore reach speeds in excess of 50 mph. They usually do not set a pattern for good riding position, comfort or road holding, but the youngsters consider them very amusing, especially for use at sea or mountain resorts or going to school, and so the manufacturers try everything to please them. Pictured are the "Go-Go" (Italjet) with "open" frame and spherical tank around the steering column and the "America" (Peripoli). ■
