1946 Moto Guzzi Dondolino

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David Roper says the 1946 Moto Guzzi Dondolino puts a smile on his face when he's riding it, and confesses sometimes he even breaks out laughing.
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David Roper's 1946 Moto Guzzi Dondolino's claimed top speed is 110mph, with the fuel capacity of 5gal (19ltr).
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The 1946 Moto Guzzi Dondolino's engine: 498.4cc OHV air-cooled horizontal single, 88mm x 82mm bore and stroke, 8.5:1 compression ratio and 33hp @ 5,500rpm.
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Dave Roper getting in some practice laps on the 1946 Moto Guzzi Dondolino at Cresson, Texas, last March.
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The 1946 Moto Guzzi Dondolino carries its oil in a tank welded on top of the gas tank, a normal Moto Guzzi practice for years.
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Choke lever for the 35mm Dell’Orto on David Roper's 1946 Moto Guzzi Dondolino.

1946 Moto Guzzi Dondolino
Claimed power:
33hp @ 5,500rpm
Top speed: 110mph
Engine: 498.4cc OHV air-cooled horizontal single
Carburetion: 35mm Dell’Orto SSM
Transmission: 4-speed, chain final drive
Weight (dry): 279lbs (127kg)
Fuel capacity: 5gal (19ltr)

This is a landmark year for a couple of reasons. 2011 marks the 65th birthday of the exquisite 1946 Moto Guzzi Dondolino campaigned by veteran racer David Roper, and it’s also the 90th anniversary of the venerable Italian firm, based in Mandello del Lario on beautiful Lake Como.

Moto Guzzi is perhaps best known for the iconic, transverse V-twin engines that have powered its motorcycles since the late 1960s. It’s easy to forget that since 1921, when Carlo Guzzi and his partners began building and selling motorcycles, the factory has produced a wide variety of engines, including inline V-twins, inline fours, parallel twins, inline triples and the crown jewel of their inspired mechanical vision and skill, the Carcano-designed transverse mounted dual-overhead cam 500cc “Otto Cilindri” V8 masterpiece of the mid-Fifties.

The original Moto Guzzis were built around horizontal single cylinder engines. These machines distinguished themselves over several decades beginning in the 1920s, with many victories and a handful of World Championships. In addition to production machines, Moto Guzzi’s race shop designed and built bikes specifically for competition. Some were works racers for factory sponsored riders, others were sold to private racers.

The Gentleman’s Racer

The 1946 Moto Guzzi Dondolino featured here is one of a series of “Gentleman’s Racers” produced to satisfy privateers who wanted to compete effectively in circuit races and other endurance events that were immensely popular in Italy.

1946 was the first year of production for the Dondolino. That year, a Dondolino piloted by Enrico Lorenzetti won the Swiss Grand Prix at Berne. A Dondolino also won the 1946 Spanish Grand Prix in Barcelona, with Nando Balzarotti riding. Dondolinos also won the second-division Italian Championships in 1946, 1948, 1950, 1951 and 1954, as well as third division titles in 1947 and 1948. They won the first division French Championships in 1948, 1949, 1950 and 1951 and the Swiss titles in 1950 and 1951.

Although there were numerous victories in circuit races, the Dondolino really proved itself in such marathon events as the Milan-Taranto race. This event was one of many great Italian long-distance road races extremely popular in the post-war years. While the Dondolino often competed in these events against more powerful machines with greater outright top speed, the Guzzi’s ruggedness and reliability afforded it stellar success in these grueling tests of rider stamina and mechanical stoutness.

The Milan-Taranto race always started on the outskirts of Milan at the stroke of midnight. Riders departed at carefully timed intervals. They raced through the night, into the dawn and through the following day, for hour after hour at full chat. The course took the riders 1,300 kilometers south — from Milan through Bologna, Florence, Siena, Rome, Cassino, Naples and finally to Taranto. People in towns and villages lined the roads, cheering as the riders flew by. Eateries and drinking holes along the route stayed open all night to provide sustenance and comfort for spectators and riders alike. Alberti Amaldo won his class in the last event in 1956, a full five years after Dondolino production had ended.

The Moto Guzzi Dondolino was an evolution of the 500cc Moto Guzzi Condor. From 1921 through the 1960s, the factory produced a succession of 500cc horizontal singles that shared many common design features. The air-cooled 500cc horizontal single has exposed hairpin valve springs and alloy head and barrel. Designed to run on the low octane fuel available in post-war Italy, claimed maximum output was 33 horsepower at 5,500rpm. A distinguishing feature of the Dondolino is Guzzi’s trademark external “Bacon Slicer” flywheel, which has an almost mesmerizing effect when the engine is running.

The Dondolino chassis features girder forks and a single rear spring mounted under the engine and semi-enclosed by a small belly pan. Other special components include crankcases and wheel hubs cast in lightweight magnesium alloy. Top speed was claimed by the factory to be more than 110mph with an open pipe. Dave’s bike weighs 279 pounds, just under the factory-quoted 282 pounds.

Dondolino is Italian for “Rocking Chair” and a charitable interpretation would draw a comparison to the “Featherbed” name given to the famous Norton frame designed by Rex McCandless, aframe renowned for its comfortable ride. The more cynical interpretation attributes the nickname to the tendency of the machine to pogo a bit when the suspension is pushed to its limits.

Motorcycles like the Condor and Dondolino were built in small batches in the Moto Guzzi race shop and their production history is hard to trace due to notoriously disorganized factory records. Built on demand, there is considerable variation in specification between individual machines. The Dondolino was manufactured between 1946 and 1951, and it’s believed 54 machines were produced. It’s hard to know how many Dondolinos were built and how many began life as Condors that were subsequently upgraded to Dondolinos. One thing was constant: you could order your Dondolino in any color you liked, as long as that color was red!

Roper purchased his Dondolino — frame number 10139 and engine number C47658 (“C” denoting “competition”) — in May 2010 from the estate of Ian Gunn, who passed away in 2008. Gunn, a respected physicist and member of the National Academy of Engineering, was also an avid motorcycle collector and racer. Amongst his significant scientific contributions was the Gunn diode, which, ironically enough, made possible the production of radar guns, much to the chagrin of many who ride motorcycles in a spirited fashion.

When Gunn passed away, he left behind a collection of more than 40 race bikes. His collection included 11 Ducatis, ranging from a DOHC racer from the late 1950s to an 888, as well as a rare green-frame 750SS. In addition, there were Manx Nortons, Aermacchis, a Gilera, an MV Agusta and many other exotic motorcycles.

Gunn bought the Dondolino at an auction at the Peterson Museum in Los Angeles in 1996. The Dondolino was shipped to Mt. Kisco, N.Y., where it remained in storage until purchased by Roper, an old friend of the Gunn family. Before putting the bike on track, Roper set about familiarizing himself with the machine, inside and out. The Dondolino was disassembled and its components carefully inspected. Overall, it was in good shape, with a fractured valve spring and a couple of small cracks in the magnesium crankcase and rear hub. The cracks were welded and piston rings replaced with modern items. Oiling to the inlet valve guide was originally by misting, and the exhaust valve guide’s only source of lubrication was oil vapor in the exhaust gases — marginal at best. Dave has since made minor modifications to allow a more adequate supply of oil to reach the guides.

He also added the “Faenza” primary cover with a third main bearing to support the external flywheel. This was a factory modification that was introduced beginning with the 1948 models. The tachometer currently on the bike is not original. The right-angle tachometer drive gearbox that came with the bike was missing a shaft and gear, and Dave hasn’t found replacements yet. He’s running a Smiths instrument until he can find the parts needed to re-install the original tachometer.

Roper’s debut race outing on the Dondolino was in March 2011 at a WERA event at Virginia International Raceway, competing in the 500GP Class. He had a few teething issues at that outing and didn’t finish. Later that month, Roper raced the Dondolino in an AHRMA event at Roebling Road, finishing second to Class C leader Alex McLean on his Norton Manx. He also rode at Cresson, Texas, finishing third in both races. A connecting rod failure at Grattan, Mich., in June, put the Dondolino out of contention for the year, and Roper’s currently putting it back together.

Although the regulations allow significant internal modifications to the machine to enhance output, Dave plans to race the Dondolino pretty much as it was when it left the factory. He’s aware of the rarity of this exceptional motorcycle and treats it with respect. He’s planning to build a second bike based on a 1960s vintage horizontal single cylinder Moto Guzzi, and that bike will be more of a workhorse on which he can test various go-faster bits. In addition to the Dondolino, Roper has a 250cc Moto Guzzi Airone, a 250cc CRTT Aermacchi, a 350cc ERTT Aermacchi and a Honda C100 Cub, all four of which feature the horizontal single-cylinder engine configuration, a cylinder arrangement Roper refers to as a “sacred architecture.”

In comparison to more modern machines he’s raced, Roper says the riding position on the Dondolino is a bit more upright and the low sprung seat gives the bike a unique feel. The narrow, 21-inch diameter tires front and rear give it light steering, and in keeping with its nickname, Dave reports that the rear wheel dances a bit when the bike’s handling is pushed. The powerband is broad and torquey; perhaps not yet as fast as some of the cammy Norton Manxes Roper competes with, but not too far off.

The Moto Guzzi Dondolino looks today much as it did when it left Lake Como 65 years ago. Its history prior to 1996 is uncertain, although it’s likely it was ridden in many events by many riders. Maybe even a Milan-Taranto or two. Privateers like Dave Roper are temporary custodians for machines such as this Moto Guzzi. Unless they’ve met an early catastrophic end — hardly unusual for a race bike — or ended up as a static exhibit, properly cared for machines like the Dondolino can compete for decades, long after their flesh-and-bone caretakers have shuffled off this mortal coil. As fascinating as it is to scrutinize such rare machines in museums, nothing compares to hearing the barking staccato of the exhaust, seeing those frantic external valve springs quiver and watching the bike being ridden in anger, as intended.

Roper says the Dondolino puts a smile on his face when he’s riding it, and confesses sometimes he even breaks out laughing. Does it really get any better than that? I’m sure Carlo Guzzi would approve. Here’s to more birthday celebrations to come. MC 

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