(This Retrospective article was printed in the July 2008 issue of Rider Magazine.)
In the mid-1970s Moto Guzzi’s outlook was affected by Alessandro de Tomaso, an Argentine of Italian background who purchased the factory lock, stock and cylinder barrel.
His marketing types took a look at the line of motorcycles and saw a pleasing array of big twins, running 850- to 1,000cc. They decided that a smaller version had a place in the market, and all hands went to work to build a half-liter model.
The factory’s lead engineer, Lino Tonti, was in charge, and he essentially downsized the 850 everywhere while using the same 90-degree, wet-sump, overhead-valve V-twin, dry single-plate clutch, five-speed transmission, shaft drive and electric starting, although with a new electronic ignition system. The 57.3-inch wheelbase of the 850 Le Mans went down to 55 inches on the V50, the advertised dry weight from 475 pounds to 336 pounds, carburetor size (Dell’Ortos) from 36mm to 24mm.
One major change was in the two-valve heads, 32.5mm intake, 27.5mm exhaust, which now used a Heron design as on the Moto Morini engines. These had the standard screw adjusters at the rocker arms, but while the big twins used slightly angled valves in relation to the piston, the V50 had the valves going straight up and down…with the combustion chamber not in the head itself but in a dished-out portion of the piston. Engineers claimed that this design improved torque characteristics as well as fuel economy, but in truth the main reason was cost, as the head needed only to be planed, not have an expensive hemispherical chamber. Cost was paramount in the mind of De Tomaso in developing this relatively small engine, as it was in redesigns of the bigger twins.
The V50’s bore and stroke was 74 x 57mm, for a total of 490cc. And the speed dropped, needless to say, in comparison to the 844cc Le Mans. We do not have reliable power ratings for these machines, but 71 horsepower at 7,300 rpm for the Le Mans was the official figure, 45 horses at 7,500 rpm for the V50. The 850 was good for over 125 mph, whereas the V50 topped out at a little over 100.
The cradle frame had detachable lower tubes to facilitate engine removal, with the engine now a mildly stressed member, and the whole drivetrain could be removed in less than an hour. Also, the swingarm now pivoted directly in the gearbox, with the right side holding the driveshaft.
The wheels were 18 inches in size, and had three discs. The rear and right front calipers squeezing on the brake discs were linked when using the brake pedal, with a proportioning valve sorting out the difference. The left disc’s caliper was responsive to the brake lever. This linked system was considered pretty high-tech by the motorcycle world, although nobody else seemed to be on that particular bandwagon…at the time.
While Tonti was building the bike, the white-collar boys were looking at the potential market. Italy had just enacted a new tax law, decreasing costs for the under 350cc crowd, so new cylinders with a bore of 66mm, stroke, 50.6mm, were built, with horsepower rated at 33.6 at a very revvy 8,100 rpm. The two models were available at Italian dealers in the early fall of 1977, and were officially presented together at the Milan show a few weeks later. The American importer, Berliner Motor Corporation, showed a distinct lack of interest.
The starter was efficient, though the engine required a bit of warm-up on a cold morning. The gearbox was several notches up on that of the big twins, requiring little effort to shift. Handling was spiffy, considering the tall, skinny tires (90/90 x 18 front, 100/90 x 18 rear), and the brakes, once the rider was accustomed to the linkage, excellent.
Italians being Italians, Tonti’s crew could not resist tinkering, and in 1979 the V50 II appeared with a conventional dual-point ignition and Nikasil coating on the cylinder bores. This nickel and silicon lining was becoming increasingly popular in European machines, as it cut down drastically on cylinder wear. Also the two-liter sump was increased by 10 percent for better lubrication.
The next year a new variant was shown, the V50 Monza, named in honor of the racetrack; a V35 version was called the Imola. The Monza had an even bigger sump, 2.5 liters, bigger valves, 34.5mm on the intake, 30.5mm on the exhaust, and bigger carburetors, now 28mm. The mufflers were tilted up a bit to enhance cornering clearance, and a little bikini fairing, clip-on bars and slightly higher primary gears improved top speed by a couple of miles. Although this put the rider in a very racy crouch…. The fork was a touch more sophisticated, with air/oil teledraulics, and the wheelbase was extended by three-quarters of an inch.
This model had Joe Berliner mildly interested, as did the companion V50 III that showed up (as in the photos) almost at the same time, virtually identical to the Monza except for slightly lower primary gearing, lacking only the fairing and a few other cosmetic touches and having a more comfortable riding position with flat bars. Berliner imported a few of both, most of which sat in showrooms.
The real trouble was the pricing. In 1981 the Monza went for $3,200, the V50 III for $200 less. The Italian jobs were expensive, with the Laverda 500 Montjuic costing $4,300, the Morini 500 Sport going for $3,200. While the Japanese 450 twins cost less than $2,000, and the 550 and 650 fours were under three grand. Which is why the V50 sold very slowly indeed; how many were actually imported to the United States is probably hidden in the dusty Berliner archives.
In Europe the V50 was turned into both a dual-purpose Tuttostrada (All-road) and a popular Custom. Over the years Tonti’s mini-Moto engine was expanded to 650 and even 750cc. The V50 III lasted until 1986, the Monza until 1989.