Dial in your spring rate
Sprindex Downhill Features
- Adjustable base spring rate with a progressive finish
- Includes spring, adjuster, and 5 performance adapters
- Lightweight (highest grade steel allows less material)
- Available in 6 spring rate range options
- 75mm / 3.0" stroke
- 162mm spring length
Sprindex allows for tool-free, easy adjustment of your coil's spring rate.
Adjusting your shock's spring rate can profoundly improve your bike's handling and suspension. In fact, you may find yourself using different spring rates for different trails, depending on the conditions and type of trail. Or you may increase your spring rate for long climbs and decrease it for down hills.
No expense was spared on the materials or manufacturing processed used. The coil itself is made of super high tensile spring steel similar to "lightweight" springs (which is why Sprindex is lighter than regular springs) in order to handle the stress of the system when adjusted to its highest spring rate setting, as well as reduce coil mass. The Sprindex assembly is made of glass reinforced polymer. The 5 included adapters are made of slippery Delrin.
Spring rate is the force required to move a spring a given distance and independent of preload. For example, a "400 lb/in" spring requires 400 pounds to move the spring 1 inch and 800 pounds to move a spring 2 inches. Preload is how much force is required to start moving the spring. Sprindex is patent pending in many countries.
Follow your shock manufacturer's instructions for preload amount and sag and other shock adjustments. Do not preload your Sprindex more than 3 turns and 1 to 2 turns is preferred.
Your Sprindex coil behaves like a regular coil that has a spring rate the same as your adjusted Sprindex spring rate. Adjusting your Sprindex does not change the length of the coil and so does not change your preload. Preload is adjusted normally and with the threaded ring that came with your shock.
Spring rate is different from preload
- A sprindex coil behaves exactly like a regular coil of the selected spring rate. For example, Sprindex adjusted to 435 lb/in behaves just like a custom made 435 lb/in standard coil.
- Poor small bump absorption resulting in a harsh ride and poor traction because it increases force to start coil movement.
- Either reduces shock travel and/or over-stresses spring.
- Improper SAG. SAG must be achieved by spring rate, not preload.
- Doesn't change coil spring rate. If you bottom out with a spring, heavy preloading may not solve this and will mess up the rest of the stroke.
How does Sprindex adjust spring rate?
The spring rate of a spring is the amount of force it takes to deflect the spring a certain distance (typically pounds per inch or Newtons per mm). Spring rate is a function of 4 characteristics: wire diameter, coil diameter, material, and number of active coils. More active coils causes a lower spring rate and fewer active coils causes a higher spring rate. Think of it like this: the less wire there is to bend, the stiffer the spring. By twisting the Dial, Sprindex works by altering the number of active coils available for deflection. The adjusted spring rate is displayed through a window in the Dial.
Sprindex is compatible with a wide variety of shocks.
There are three different Sprindex lengths and strokes available, and each Sprindex coil can be adjusted through a certain spring rate range. Be sure to use the correct included adapter as described. Make sure that the spring length fits on your shock and that your maximum shock travel is not more than the specified Sprindex coil travel.