Race Tech Front And Rear Suspension Swap
Ridin' On Caddies
By: Jordan Mastagni, Race Tech, Photography by Jordan Mastagni, Race Tech
Damping Rod Basics
According to Race Tech, Damping rod forks don't work very well in stock form. A damping rod fork controls the oil flow through a series of simple fixed size holes in a tube. The problem is these holes are only the right size for one type of bump so 90 percent of the time they are too big or too small. For instance when the fork encounters a slow speed movement (speed the fork compresses not how fast the bike is going) from a small bump or dip the oil flows un-restricted and too quickly resulting in a vague or mushy feel to the rider. When a high-speed fork movement is required from a large or sharp edge bump the damping rod holes are too small for proper oil flow resulting in harshness due to the fork not compressing fast enough. This effect is referred to as Velocity Squared Damping (V) as the oil velocity squares based on the speed of the fork compression.
When the Gold Valve Emulator is installed the compression holes at the bottom of the damping rod are over-drilled so that they no longer restrict the oil flow through the center of the damping rod. As the oil reaches the Emulator it is first controlled by a small by-pass hole in the Emulator Check plate. This small opening provides for a firm controlled feel to the rider when slow velocity smooth edge bumps are encountered. When a sharp or square edge bump increases the velocity of fork compression the spring loaded check valve on the Emulator controls the oil flow and acts as a variable valve. Based on a combination of spring rate (several check plate spring options are provided with the Gold Valve Emulator kit) and the Emulator check spring preload setting, the damping is no longer a V damping characteristic but instead the damping becomes nearly identical to the way a Cartridge fork performs in a digressive velocity manner offered by modern bending shim stacks found in a cartridge fork. The Gold Valve Emulator controls compression damping completely while rebound damping is controlled by oil viscosity (typically 15-30w) the Emulator offers enough adjustability to work with any weight of oil required for optimum rebound control. So essentially, the harshness is removed from the fork action resulting in a firm yet plush ride with much greater feedback and control to the rider under varying ride conditions.
By Jordan Mastagni, Race Tech
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