The Ducati 450 R/T – inspiration for the firm’s modern-day street scramblers
The progenitor of the Italian firm’s scrambler species was a bike they tagged a ‘motorcycle to be reckoned with’
Modern motorcyclists have embraced a whole new world of ‘street scrambler’ motorcycles in recent years – and Ducati have been at the forefront of this style, since launching their 800cc Scrambler at Intermot in the autumn of 2014.
The Scrambler concept was a revival of a range Ducati had launched in 1962 and was in production until 1974. The factory had been involved in off-road competition from the 1950s, with a range of singlecylinder bikes including an International Six Days Trial medal-winning overhead-valve 65cc, through other capacities from 125cc, 200cc, 250cc and 350cc to 450cc, primarily for the home and US markets.
The 450 R/T, which featured a brand new engine design, was introduced as a more serious off-road bike than the previous Scrambler models – as requested by Ducati’s US importer Berliner. Ducati had employed 1966 Italian scrambles champion Walter Reggioli to assist with the development of the bike and production commenced at the end of 1970.
The engine’s capacity was actually 425.5cc, with a bore of 85mm and a 75mm stroke. It had a compression ratio of 9.3:1 and was fed by a VHB 29mm AD carburettor. The engine produced 27bhp at 6500rpm.
The frame was braced with gusseting along the top tube under the fuel tank. There was also a range of different sprockets available for the bike, to give final drive ratio options for its intended use in competition.
Berliner marketed the stock 1970 Scrambler in the States as the ‘Jupiter’ for just one year, during which it was available in vibrant yellow livery only.
For 1971, though – again at the request of Berliner – the Scrambler came with a 450 desmodromic engine that was the same as that used in the stock 450 Desmo road bike (435.6cc, with a bore and stroke of 86 x 75mm and rev limit of 8500rpm, with an added decompressor fitted behind the bevel shaft) and a Dell’orto 29mm VHB carburettor, with owners supplied with three optional main jets.
This was Ducati’s most serious off-roader. The frame was completely different to any other Ducati single, with a three-tube backbone and taper roller bearing steering head. The forks were 35mm Marzocchi motocross items with seven inches of travel, while the twin shocks were 320mm Marzocchis. The swingarm came with snail-cam rear wheel adjusters and a chain guide. Alloy rims were by Borrani with Pirelli Cross tyres (3.00 x 21in front, 4.00 x 18in rear). Brakes were a 158mm diameter, single-leading shoe, front drum and 160mm rear drum. The mudguards were glassfibre and the machine had an overall weight of 124kg.
The bike was marketed as a 450R/S in Italy, but was known as the R/T in the States, where Berliner’s advertising slogan was: ‘The motorcycle to be reckoned with’. As originally supplied to the US, the bike had no road-going equipment, a short high-level exhaust pipe (though later models came with a low-level pipe) and used magneto ignition. Versions for other markets had a battery, lights, instruments, a different air cleaner arrangement and a low-level silencer.
A handful of 350cc non-desmo versions were also built in 1974 for the domestic market. Pictured is a 1971 US model R/T, restored to near-original spec.
‘1966 ITALIAN SCRAMBLES CHAMPION WALTER REGGIOLI WAS EMPLOYED TO ASSIST WITH ITS DEVELOPMENT’