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DUCATI DARMAH SD / SSD

Article #8, 11 April by Harné Heuvelman

Although the introduction of the 860 GT brought the new ‘square case’ 863cc engine, it was a big misconception. The design was a failure as it still struggles to find a place in hearts and souls of classic Ducati enthusiasts. Sales were never on the forecasted level and the model died a slow death…

Ducati learned from the 860 GT failure, shown by the introduction of the 900 Sport Desmo ‘Darmah’ or 900 SD in 1977. Although the two models were available simultaneously until 1979, the Darmah is regarded as the better sporty touring bike of the two.

A number of improvements were introduced on the 900 SD in 1977. The crankshaft bearings were updated, the crankpin was enlarged and desmodromic camshafts were now standard like on the 900 SS. Perhaps the biggest improvement was the new gearshift selector drum now located on the left side. This meant an end for the rather simply constructed crossover rod to make left-side gearshift possible in 1976. Bosch ignition replaced Ducati’s own and an electric starter motor was standard.

The technical improvements of the 900 SD Darmah saw their way to all other Ducati bevel twins of 1978. The 900 SS and even the troubled 860 GTS (now called the 900 GTS) got the same updates.

Although the frame was much like that of the 860 GT, all bodywork was new. The fuel tank and seat formed a nice partnership by sharing a line all the way over the ‘ducktail’ end of the bike. Instruments were now Nippon Denso and the 900 SD was fitted with gold finished Camagnolo magnesium wheels. Leopoldo Tartarini’s design worked well and reception looked promising in 1977.

The anticipated success came and in 1978 some minor updates were introduced. The 1977 Darmah had a Ceriani front fork, replaced by a Marzocchi front fork in 1978. The wheels were now Speedline. During 1978 the Lafranconi exhaust mufflers were replaced by Silentiums and the kick-start lever was removed.

The success of the 900 SD made Ducati management think about possibilities to add a sporty version to the range. In 1978 the 900 Super Sport Desmo ‘Darmah’ or 900 SSD was introduced, based on the standard 900 SD. The 900 SSD featured clip-on handlebars and a half fairing in 900 Super Sport style. The basic layout of the engine and chassis remained the same, albeit with a slightly higher compression ratio.

For the ‘regular’ 900 SD, a new dual seat with thicker padding was introduced in 1979 and in 1980 FPS aluminium wheels replaced the Speedlines. Along with some minor changes, the final 900 SD Darmah of 1982 received a new colour scheme.

The 900 SSD had only minor updates over the course of its lifetime. It got FPS wheels replacing the Speedlines in 1979 and revised foot pegs in 1980. Unlike the 900 SD the 900 SSD never caught on, probably because it was too heavy for a true sport bike and too sporty for a true tour bike. With the 900 S2 replacing both the 900 SS and 900 SSD, production ended in 1981. It is now one of the rarest bevel twins and with its two-tone blue finish, still a great bike.

The 900 S2 was also meant to replace the 900 SD in 1982. One can argue whether the S2 could ever replace the comfortable features of the 900 SD, but production stopped in the same year. The Darmah is probably the most undervalued of all bevel twins. It offers great handling and performance, especially with 40mm Dell’Orto’s and Conti mufflers (an extra fitted to many Darmah’s at the time), combined with a very comfortable ride. A great bike and great value for money, even now!

Engine

The 863cc ‘square case’ L-twin was introduced on the 860 GT in 1974 and formed the basis for all other ‘square case’ models introduced later on. Although technically based on the 750 ‘round case’ L-twin, this engine had a lot of improvements for faster and simpler assembly. The outer engine cases were designed by Giorgetto Guigiaro of Studio Italdesign. The engine has vertically split aluminium crankcases, a 90 degree L-twin layout with the vertical cylinder inclined at 15 degrees upwards.

With the introduction of the 900 SD Darmah, the crankshaft bearings were updated and the crankpin was enlarged. All Darmah’s have and desmodromic camshafts and 32mm Dell’Orto’s, although from 1978 on the cylinder heads were with the 900 SS, making it possible to fit 40mm Dell’Orto’s. Perhaps the biggest improvement in 1977 was the new gearshift selector drum now located on the left side. This meant an end for the rather simply constructed crossover rod to make left-side gearshift possible in 1976. Bosch ignition replaced Ducati’s own and an electric starter motor was standard.

Frame

The frame was taken from the 860 GT and featured an eccentric pivot chain adjusters and kinked front down tubes, flattened at the end. The chain adjusters got an update in 1982 sharing those of the 900 SS. The front fork was Ceriani until 1978 when it was replaced by a Marzocchi 38mm. 900 SD’s of ’77 – ’79 were fitted with undrilled, four bolt, Brembo disc brakes front and rear. This was changed in 1980 when it received the drilled, six bolt Brembo disc brakes shared with all 900 SSD’s. Only 1977 900 SD’s were fitted with Campagnolo magnesium wheels, replaced in 1978 by Speedline magnesium wheels and, again, in 1980 with FPS aluminium wheels. Only very early 900 SSD’s came with Speedlines, soon to be replaced by FPS’s.

All bodywork was specifically designed for the Darmah and features a 15 litre fuel tank, a duck-tail seat and tiger headed side covers. In 1979 the seat was thickened and hinged side covers were fitted. The 900 SD was available in red/white, from 1978 on also in black/gold. The 1982 900 SD was available in silver, blue or burgundy. All 900 SSD’s are two-tone blue.

References (recommended further reading)

Falloon, Ian (2004) Standard Catalog of Ducati Motorcycles, Iola: KP Books

Falloon, Ian (2008) ‘The Ducati Bible: 860, 900 & Mille All models 1975 to 1986, Dorchester; Veloce Publishing

Falloon, Ian (1998) ‘Ducati Twins Restoration Guide, Bevel Drive 1971 – 1985’, Osceola; MBI Publishing Company

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