Shock absorber design was changed slightly in 2005 to incorporate an elevated vent tube to prevent oil loss in the event of a tip-over. The factory-fitted mono shock has three-way dampening, using a combination of internal coil spring, air and hydraulic fluid (oil). Air pressure is used to adjust the mono shock depending on the load at any time. The mono shock is a sealed unit and not able to be repaired or re-built if it fails. Such failures after relatively low mileage were common-place in early years and were replaced under warranty. Third party, after-market replacement units are popular with owners despite the fact they are more expensive than original (OEM), as they are serviceable and can be re-built if necessary.