Read this entire installation manual prior to installing and using your Sprindex coil. Be sure that the Sprindex stroke is at least as long as your shock rating. It is okay if your shock stroke is less than the Sprindex stroke maximum.
Above: Installation on shocks such as Fox, DVO, X-Fusion, Cane Creek, and Ohlins require 2 Performance Adapters (included). Determine which of the included Performance Adapters to use (shock brands are identified on back of Performance Adapters). For Fox shocks, use both their aluminum adapter AND the Sprindex Performance Adapters.
Above: Installation on shocks such as Rockshox do not require any Performance Adapter but we recommend using the Performance Washer Adapter (included).
The Sprindex coil can be installed in either direction and should be installed in the direction that provides the best adjusting access. If your entire shock has good access, then install the Sprindex with the Dial away from the piggyback for easiest hand access.
Direction 1 okay
Direction 2 okay
Sprindex coils fit a wide variety of shocks, but you must use the included Performance Adapters for most of them. Our Performance Adapters both improve the fit between the coil and your shock and are made of low friction Delrin to improve shock performance by allowing the spring to twist during high deflection. Also, the Performance Adapters help prevent the preload ring from self-adjusting due to coil windup. See bottom of Performance Adapter for direction of which adapter you should use. For Rockshox, no Performance Adapter is necessary but we recommend you use the Performance Washer for improved shock function.
5 size Performance Adapters are included to fit a wide variety of shocks.
For most shocks such as Fox, DVO, Cane Creek, and X-Fusion, use one Performance Adapter at each end. Use the Performance Adapter that best centers the coil on the shock at both ends (takes out the most play).
For Rockshox, Performance Adapters are not necessary but we recommend using the included Performance Washer Adapter on the preload ring end to provide a low friction surface for improved shock performance and to increase the coil length if necessary.
Follow your shock maker's instructions for changing coil spring which are typically:
To adjust the spring rate, hold the coil with one hand and twist the Dial with your other hand or vice versa. The spring rate value is identified by the printed number on the coil displayed through the Dial opening (for example, 370 lb/in in the picture above). You can even adjust the spring rate at different points of your ride depending on the trail or conditions. Preload is not a substitute for a spring that is too weak.
After installation, all shock adjustments including preload, sag, and other settings based on your shock maker's recommendations. However, remember that the sag setting is really only a predictor of proper shock setup and that obtaining near full shock travel during your ride is what is most important. So after setting up your sag, which is a good starting point, go ride and then adjust your Sprindex as needed to obtain near full shock travel on whatever is the most extreme area of your ride, without regard for sag percentage. Remember to further stiffen your Sprindex for any trails that will likely cause even more shock travel.
For your first ride, position the rubber shock bumper so that you can see how much travel your shock reaches and adjust your spring rate accordingly. Periodically check the travel of your shock and adjust your spring rate as necessary to provide you your ideal ride.
Make sure that your shock is ready to ride
WARNING: Check for clearance before riding. If you are installing your shock on a bike for which the shock was not original equipment, follow the steps below to ensure proper clearance before riding.
Remove the coil spring from your shock.
WARNING: Rear shock setup and configuration varies greatly between different bicycle manufacturers. Be sure to refer to the owner's manual for your bicycle. Sprindex products should be installed by a qualified bicycle service technician. Improperly installed shocks can fail, causing the rider to lose control, resulting in SERIOUS INJURY OR DEATH.
WARNING: All shock mounting hardware will have some inherent level of axial float which is required to achieve smooth performance. This is normal and is not a safety or performance concern. If your shock mounting hardware exhibits what you believe to be excessive float or makes noise, please contact your shock brand for assistance. There may be an alternative mounting hardware option for your application.
WARNING: Unless your shock brand advises differently, tighten the preload adjuster just until the spring no longer moves, then preload no more than 2 full turns. Preloading the spring more than 2 full turns may cause the spring to coil bind when the shock is bottomed out. This can cause damage to the shock which could lead to a loss of control resulting in SERIOUS INJURY OR DEATH.
WARNING: Shocks should be serviced by a qualified bicycle service technician. If you have any doubt whether or not you can properly service your shock, then DO NOT attempt it. Improperly serviced products can fail, causing the rider to lose control resulting in SERIOUS INJURY OR DEATH.
WARNING: Whether too stiff or too soft, the wrong spring rate can cause your shock to perform poorly, causing the rider to lose control resulting SERIOUS INJURY OR DEATH. Adjust your shock per your shock brand's recommendations.
Installation and using the Yo-Yo Stroke Gauge
Most people riding coil shocks do not achieve full stroke travel, which greatly affects performance. Stroke travel is typically hard to measure with coil shocks. By using this Yo-Yo Gauge, measuring your stroke travel is easy to see and allows you to fine tune your Sprindex to the optimal setting. The Yo-Yo is meant to be used temporarily during rides in order to dial in your Sprindex spring rate.
Step 1. Remove spring. Install shock without spring.
Step 2: Install Velcro. Ideally, install Velcro on or near shock Eyes or in locations that move about the same distance as the shock Eyes.
Step 3: Install Yo-Yo by pushing the centers of Velcro together. Slide stroke Bead towards Reel.
Step 4: Fully compress shock. Note that this includes compressing the rubber Bumper.
Step 5: Fully extend shock. Mark string near stroke Bead with Sharpie pen (shown here marked in red).
Step 6: Install Sprindex per instructions at the top of this page. To reset, slide stroke Bead towards Reel after every Sprindex rate adjustment.
As shown, more stroke is available. If this was after your biggest drop, adjust Sprindex rate lower in order to be able to use more shock stroke.
As shown, full shock stroke was achieved or possibly bottomed out. It is usually best to achieve slightly less than 100% full stroke to be sure you did not bottom out completely. Adjust Sprindex rate higher, especially if you expect to hit the ground harder.
Alternative installation. With some bikes, it is impossible to install the Tab and Reel in locations near the shock Eyes. In those cases, install Tab and Reel in locations that move approximately the same stroke distance as the shock stroke. Be sure to determine full stroke by following steps 3-5.
The Yo-Yo can also be used to determine SAG percentage. But remember that SAG is only based on rider weight and body position. SAG is a starting point but does not consider riding style, how aggressive you ride trails, etc. A much better measure of desireable spring rate is how much shock stroke is used during your ride.