Classic bike: Ducati 450 Desmo

Single-cylinder motorcycles were once the mainstay of the British motorcycle industry, but Edward Turner’s Triumph Speed Twin ended that reign. By the 1960s most British singles were consigned to the scrap heap, but in Italy the single-cylinder still dominated. The reason for this was the Italian motorcycle industry grew out of small capacity motorcycles initially created to provide mass transportation in a country devastated by war.

Ducati began in 1946 with the 50cc Cucciolo and over the next decade its single gradually expanded to 100, 125, 175, 200, and then 250cc. By the mid-1960s it was at its limit at 350cc, and a new wide-case Ducati single was displayed at the Cologne Show in September 1967.

This revised engine allowed for the capacity to be eventually increased to 436cc, also allowing Ing Fabio Taglioni to make his dream a reality: to create the first production engine with desmodromic valve gear.

In 1969 the 450 (actually 435.7cc) became available and featured a new crankcase, cylinder, and cylinder-head castings to accommodate the 86mm x 75mm dimensions. Shortly afterwards a desmo 450 appeared, at the time the spearhead of Ducati’s line-up alongside the cosmetically identical 250 and 350. To aid starting the 450 desmo had a slightly lower 9.3:1 compression ratio and a new Dell’Orto VHB 29 square-slide carburetor and, while it was more powerful than the 250, there wasn’t much difference between it and the 350 in outright performance.

Until 1970 the desmo and regular-valve-spring Mark 3 were virtually indistinguishable, but in 1971 the desmo single was given a makeover to become one of the first factory café racers. A gaudy metalflake silver paint scheme was provided for the fibreglass petrol tank, side covers and solo seat, while rear-set footpegs complemented the clip-on handlebars. Later the little desmo acquired the nickname ‘The Silver Shotgun’, the term actually coined by an Aussie bike magazine in a 1974 owner's report.

More improvement was evident with the running gear. Borrani 18-inch alloy rims replaced the previous steel type and the front brake became a Grimeca double-sided leading shoe instead of the rather weak single leading shoe that had been fitted from 1957.

The fork was considerably uprated from the previous spindly 31.5mm units, being a new type of 35mm Marzocchi fork with exposed staunchions. Only the barest concession was made for street legality, with a large white Veglia tachometer dominating the instrument layout.

But the 450 desmo was still a single. Although at around 130kg it was incredibly light, it was no powerhouse. On a good day you might see 160km/h, but the vibration ensured you didn’t hold it for long. And this was not a bike to be riding after dark, as the 6V headlight provided illumination similar to that of a candle.

But get one on a smooth twisty road and these can be one of the most satisfying vintage sports motorcycles to ride. With their long wheelbase and slow steering, the 750s and 900s are renowned for their stability and heavy handling, especially on tighter roads, but not so a desmo single. Compared to a Ducati bevel twin, the singles were light, short and agile. They were not particularly stable on bumpy roads, as I found out to my detriment 25 years ago.

So what is the appeal of the Ducati single? For years they lived in the shadow of the 750 and 900 but now a good desmo single is worth significantly more than some of the lesser twins. The desmo single, particularly the 1971-72 ‘Silver Shotgun’, represented the end of an era for sporting Italian motorcycles. These bikes were expensive to manufacture so they were not built after 1974.

With their loud exhaust and open carburetor they made no concession to noise, emission controls or civility, and they were pared down to the essentials. This was minimalist motorcycling: the 450 desmo represents the end of a never-to-return era.

If you fancy sticking a Silver Shotgun in your own shed, these are the numbers you’ll need to run past your bank manager…

Get this book:
The Ducati Story, available from

This is a great site for Ducati singles:
www.motoscrubs.com/Duc_Technical.htm

There’s a nice gallery of singles here:
www.bevelheaven.com/gallery-singles.htm

There’s more info here:
http://motorbike-search-engine.co.uk/classic_bikes/ducati-classic-motorcycles.php

Story courtesy of Motorcycle Trader