Report From Italy
REPORT FROM ITALY
CARLO PERELLI
FIFTY-CC RACING IS tremendous fun at low cost, provided the organizers stick to a real "sports machine" formula, banning such highly developed but fantastically complicated racers as the Honda, Kreidler and Suzuki, which are not available to privateers. Moreover, fifty-cc racing is ideal for beginners and can be held on short and more easily available circuits, simplifying the myriad of organizing tasks. And success of 50cc racing in this form (contrary to world championship races where participation consists of a few works riders) is evident all over Europe and particularly in France, Belgium and Holland, backed by the easy availability of machines and parts at appealing prices.
Latest addition to these models is the "Vampire," built at Bologna by Italjet, the firm owned by enthusiastic former champion Leopoldo Tartarini, who did a world tour some years ago with a Ducati. The Vampire is sold in Italy for the equivalent of 300 U.S. dollars, fairing included and ready to race. Powered by a hottedup version of the F. B. Minarelli conventional two-stroke engine, it develops 7 bhp at the rear wheel at 11,000 rpm and features a close ratio four-speed gearbox in unit. Bore and stroke are 38.8 x 42 = 49.9cc and compression is 13:1 so that pump gasoline can be used with only 25:1 (4%) oil lubrication.
The flat-topped piston has only one Ltype ring while the combustion chamber is shaped to create a good squish effect. The light alloy cylinder head is deeply finned, with the side fins directed toward the center to improve cooling of the plug. The cylinder, cast in iron as usual, also has square profile fins. Carburetion is by a 20mm Dellorto, ignition by flywheel magneto on the left (where the drive for the tach is also fitted) and external HT coil; primary drive by gears and multiplate clutch in oil bath are both on the right.
The frame design is somewhat unconventional since the double cradle runs above the crankcase, the power unit hanging under it, attached by means of metal plates. This chrome-moly tubular frame weighs only 10V^ pounds; tank, seat and quickly-detachabte fairing are made of fiberglass, pedal controls are of light alloy plate. Total weight is only 121 pounds in full running trim. Orthodox suspension is employed, and worthy of note is the 120mm four-shoe front brake (the rear one, of normal two-shoe type, has a 105mm diameter); tires are 2.00-18.
Short test riding on the Monza autodrome, where the bike was introduced to the press recently, confirmed that the Vampire can offer a lot of fun. In spite of the large bore carburetor, starting is easy and acceleration clean. The best rpm range seems to be between 9000 and 11,000 rpm, even though the engine is quite lively below 9000. Exhaust noise, thanks to the expansion chamber which also aids breathing, is so low that the machine could be used on city streets without offending anyone's ears!
Every control can be quickly and easily actuated; the gearshift lever is on the left (shifting is of the "up for up" type); the tach is at the left of the two-piece handlebar; and the rider can tuck in very well on the bike - protected by the fairing and putting his chin on the comfortable padded tank — provided he's not too tall. Road-holding is basically good but could be improved with better suspension and racing tires. Braking is satisfactory, especially on the front, and top speed has been timed at 80.7 mph, a considerable figure for such a machine.
