Ducati returns to producing a road single-cylinder, 30 years after the legendary Supermono 550.
It is called Superquadro Mono, has a displacement of 659 cc, is equipped with a Desmodromic system and sets itself as the new benchmark in the category in terms of performance.
This single-cylinder, designed by choosing refined materials and solutions for each component, is based on the Panigale 1299 engine, the 1285 cc Superquadro, which represents the maximum evolution of the Ducati street-legal twin-cylinder. The Superquadro Mono inherits the 116 mm diameter piston from the Panigale engine, the shape of the combustion chamber, the 46.8 mm diameter titanium intake valves, the 38.2 mm steel exhaust valves and the Desmodromic system.
The name Superquadro comes from the extreme ratio between bore and stroke which allows, thanks to the very short stroke, to reach rotation speeds typical of racing engines. On the Superquadro Mono this ratio is equal to 1.86 and is the most extreme in the category thanks to a stroke of just 62.4 mm. The record bore of 116 mm allows the adoption of large diameter valves to benefit performance, which however would not be possible without the Desmodromic system. This system, which Ducati also uses on the MotoGP bikes, allows the limits imposed by the valve springs to be overcome, enabling extreme valve lift laws. In this way, the Desmodromic system contributes significantly both to performance and to the possibility of reaching very high rotation speeds.
Thanks to these solutions, the Superquadro Mono delivers a maximum power of 77.5 hp at 9,750 rpm, and is capable of reaching 10,250 rpm*, values never achieved before by a road single-cylinder. The torque, whose maximum value is 6.4 kgm at 8,000 rpm, is distributed in a particularly favourable manner, resulting in linear and exploitable power delivery. All this while respecting the limits of Euro 5 homologation. In racing configuration with Termignoni exhaust, this single-cylinder is finally able to reach the incredible maximum power value of 84.5 hp at 9,500 rpm.
The Superquadro Mono will also be used on motorcycles for A2 licence holders in a detuned version.
At this link you will find the 3D video of the Superquadro Mono engine.
Technical solutions and refined materials for performance and lightness
The 116 mm bore piston is an absolute record for a production single cylinder. Of racing origin, it is characterized by a “box in box” layout like the pistons of the Panigale V4 R, i.e. with a double-truss base to combine rigidity and resistance by reducing the thrust surfaces with the ultimate aim of containing friction. For the same reason, the piston pin is equipped with a Diamond Like Carbon (DLC) surface coating, the same treatment used for the piston skirt of the Panigale V4 R. The compression ratio is equal to 13.1:1.
As on the Desmosedici MotoGP engine, the rocker arms of the Desmodromic system also boast DLC (Diamond Like Carbon) surface coating to reduce friction and increase resistance to fatigue. Distribution is controlled through a mixed “silent” gear/chain system.
Fuel feed is entrusted to a single oval-section throttle body with an equivalent diameter of 62 mm, with an under-throttle injector controlled by a ride-by-wire system that offers three different Power Modes (High, Medium, Low) to adapt the delivery of the engine to different riding situations.
The die-cast engine crankcases integrate the water jacket around the cylinder barrel, made as on the 1299 Superleggera in aluminium rather than steel, with benefits in terms of weight and cooling due to the thinness of the walls. This solution also allows the head to be fixed directly to the crankcase, obtaining a much more compact engine with the same rigidity of the structure. The clutch, alternator and head covers are made by casting magnesium alloy, again to reduce the weight of the engine to a minimum while guaranteeing high mechanical resistance.
The crankshaft is asymmetrical and mounted on differentiated main bearings to contain the weight. Engine balancing is guaranteed by the presence of two balancing countershafts (one front and one rear) mounted on ball bearings inside the crankcase and controlled by gears. The countershafts also control the water and oil pumps.
The layout of the two countershafts, placed on the side of the crankshaft, allows the first order inertia forces to be completely balanced without introducing further unwanted forces or moments. Thanks to this solution the engine is capable of running at very high speeds while maintaining a vibration level comparable to a 90° V-twin.
The Superquadro Mono relies on two lobe pumps, a delivery one which ensures efficient lubrication of the engine, and a recovery one, located in the connecting rod compartment and which takes the oil from the side compartments of the alternator and clutch covers in order to reduce the friction losses of the lubricant with the moving parts. This pump, together with a valve placed in the blow-by circuit, brings the crankshaft compartment under depression as in racing engines, in order to reduce the resistance of the moving parts and to ensure effective recovery of the lubricating oil in any conditions of use of the engine.
The transmission relies on a six-speed gearbox with racing ratios derived from the experience gained with the Panigale V4. The first gear is in fact long to allow its use in slow corners, exploiting the maximum thrust available. The clutch is in an oil bath with progressive interlocking hydraulic control, characterized by a particularly reduced lever load and specifically developed to offer easy and intuitive braking behaviour, with maximum modulability on release and in engine brake management to facilitate power-sliding in corner entry.
The gearbox can be equipped with Ducati Quick Shift (DQS) Up & Down. In this application, the DQS relies on a magnetic hall effect sensor and not the traditional load cell to improve accuracy and reliability.
The Superquadro Mono will equip the bike that will star in the fifth episode of the Ducati World Première 2024 “Live. Play. Ride.” on Thursday November 2nd at 4.00 pm CET on Ducati.com and on Ducati’s YouTube channel.
*In first gear only the limiter is set at 10,000 rpm
Main technical data of the Superquadro Mono
- 659 cc vertical single-cylinder engine
- Bore x stroke 116 x 62.4 mm
- Compression ratio 13.1:1
- Maximum power 57 kW (77.5 hp) at 9,750 rpm – 84.5 hp at 9,500 rpm with Termignoni racing exhaust
- Maximum torque 63 Nm (6.4 Kgm) at 8,050 rpm – 6.8 Kgm with Termignoni racing exhaust
- Aluminium cylinder barrel
- Euro 5+ homologation
- Mixed chain-gear Desmodromic distribution with double overhead camshaft, 4 valves per cylinder. 46.8 mm titanium intake valves, 38.2 mm exhaust valves.
- Asymmetrical crankshaft mounted on differentiated diameter main bearings
- Double balancing countershaft with control function of the water and oil pumps
- Multi-disc oil-bath clutch, servo-driven and with anti-hopping function
- Semi-dry sump lubrication with delivery pump and recovery pump
- Fuel feed via oval section throttle body with an equivalent diameter of 62 mm
- Six-speed gearbox with the possibility of fitting the Ducati Quick Shift (DQS) Up & Down
- Oil change set at 15,000 km
- Check and eventual adjustment of valve clearance set at 30,000 km
Original post on modernclassicbikes.co.uk and published by Frank Duggan. Frank is the Founder and Editor of Modern Classic Motorcycle News, an independent motorcycle publication covering modern classic motorcycles, roadsters, scramblers, cruisers, electric motorcycles and the wider motorcycle industry.
