The hydraulic machines are true masterpieces… and it was also born thanks to an enthusiastic key person, Technical Director Norbert Rueckgauer, that pushed his organisation beyond the comfortable zone. At Bosch-Brueninghaus the engineering staff was up and running with small, effective hydraulic pumps and motors that worked just fine for forest machine and mechanical saws but Öhlins sat down in a meeting with the company and presented the wish-list for a 2WD motor.
The bearings needed to be even more friction efficient, all fittings needed to be more precise and the housing had to be in aluminium instead of steel. It also had to be compact and cope with as much as 14 500 rpm which is the case in hypersport front wheels.
The engineers put their feet down and told it was impossible but Herr Rueckgauer ordered the engineers to make this happen. If the Öhlins guys say so it must be possible he told them.
The first hydraulic system had a 6 litre oil tank but we soon removed the tank and the complete system contains only ½ litres of oil now. In hypersport bikes we need to install a small cooler as the velocity of the hydraulic fluid is really high, pushing the temperature up when the bike travels in full speed.
We also needed to prevent too high pressure inside the system if the bike were to stand in a greasy pothole with the rear tyre, resulting in a massive torque transmission to the front wheel that might exceed 1000 bars at full throttle. It resulted in valves that is activated by temperature and high pressures – leading the hydraulic oil back to the pump inlet without passing the motor.