Ducati & MV Agusta Rear Suspension Parts
If you'd like to know just exactly what all these different "rear suspension pins" are, then you've come to the right place!Most motorcycles, especially those that aren't designed for high-performance use, have a very simple swingarm suspension. The rear wheel is mounted to the swingarm, which is hinged just behind the engine. A shock absorber (sometimes two) mounts between the swingarm and the chassis. The spring on the shock absorber supports the weight of the rear of the motorcycle and allows some give when the bike travels over a bump in the road.
This system works, but it has serious limitations when it comes to high-speed handling. Modern hypersport motorcycles have a different suspension design which allows the rider to maintain much better control over the bike, whether cruising down the road or barreling down the racetrack at 200 MPH. This revised design uses a rocker mechanism in addition to a shock absorber. This design is used on most Ducati motorcycles and both the MV F4 and Brutale. The following figure shows the rear suspension parts on a Ducati 996. The design is very similar for other models.
This mechanism changes the ratio at which the shock is coupled to the swingarm. Instead of a direct connection as with most "cruiser" type motorcycles, the rocker mechanism creates a rising-rate linkage which means that the shock absorber has a higher displacement than the actual travel of the swingarm. This gives the shock greater control over the rear wheel as it reacts to bumps or dips in the road. However, it also has additional moving parts, the function of which is critical to how the motorcycle handles.
The ROCKER PIVOT PIN is the "hinge pin" that mounts the rocker itself to the motorcycle's frame.
The RIDE HEIGHT ADJUSTER PIN is the pin which connects the top end of the ride-height adjuster to the rocker.
The UPPER SHOCK PIN is the pin which connects the top of the rear shock absorber to the rocker.
the LOWER PIVOT PIN is the pin where both the ride height adjuster and the rear shock join the swingarm. (This is one single part on the Ducati 916 family of bikes. On other models this is two separate bolts).
So why are these parts so important?
First, these parts are all "hinge pins". They secure moving parts which must be able to rotate freely as the suspension works. Consequently it is important that these parts have a smooth, hard surface in order to maintain proper suspension travel. TPO Parts Titanium pins are made from billet 6AL-4V Titanium and are machined to a high quality finish. The strength and hardness of the Titanium allows these parts to function better than the stock steel parts, which are often finished with a rough zinc plating (similar to construction nails). Furthermore, Titanium cannot rust and is extremely corrosion resistant, which keeps these parts working smoothly long after steel parts fail.Second, everything but the rocker pivot is unsprung weight. Unsprung weight is the weight of those parts on the motorcycle which is not supported directly by the suspension. Reducing unsprung weight is an excellent way to improve the handling of a motorcycle becasue it allows the suspension to respond faster, keeping the power on the road and keeping the rider in control. TPO Parts Titanium Pins are approximatley half the weight of the stock steel pins, which keeps your unsprung weight down.
