Sprindex Adjustable Coil Rear Spring Parts

Most people agree that a coil shock has some pretty noticeable performance advantages over an air shock. They offer improvements to small bump sensitivity, traction, and better heat management for a more consistent feel during long descents. The issue for many people is that the standard 50lbs increment between springs often makes it impossible to find the perfect spring to suit their body weight. Their shock will never offer the performance it should as they’ll be stuck between having a spring that’s a little too soft, or a little too stiff.

The Sprindex Adjustable Coil Rear Springs allows riders to easily finely adjust their spring rate to find the perfect setting to suit any rider weight, trail type, or riding conditions.

Can’t I do the same thing with preload? No. Preloading does not change the spring rate, but it does change the force to start moving the shock. Mountain bike shocks are designed for as little preload as necessary to take play out of the system. Too much preload dramatically reduces shock performance over smaller bumps, making for a harsher ride and reduced traction.

Sprindex works by altering the number of active coils available for deflection. The spring’s active coils are the coils that can flex as the spring is compressed. Fewer active coils make for a stiffer spring and vice versa. Adjusting the Sprindex does not change the length of the coil so it doesn’t affect the preload. Preload is adjusted normally with the threaded ring that comes with your shock.

Who’s this item for: These springs are for riders that want the ability to fine-tune the stiffness of their spring to suit their riding weight, the trails they’re riding, or to cater to different scenarios they might encounter during their ride.

Material: The coil itself is made of super high tensile spring steel similar to what other brands use on their lightweight steel springs. This ensures that the spring is strong enough to handle the stress of the system when adjusted to its highest spring rate setting, while also reducing coil mass. The adjustment assembly is made of glass-reinforced polymer, and the spring adaptors are made from slippery Delrin.

Spring Sizing: There are three different Sprindex lengths and strokes available, and each Sprindex coil can be adjusted through a certain spring rate range. 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.

• Downhill 75mm: 75mm / 3.0″ stroke – 160mm spring length
• Trail – Enduro 65mm: 65mm / 2.6″ stroke – 142mm spring length
• Light Trail 55mm: 55mm / 2.2″ stroke – 126mm spring length

See the link to the Sprindex compatibility chart under the Links & More Info tab

Compatibility: The included Performance Adaptors allow Sprindex to fit nearly shocks. They improve the fit between the coil and the shock while improving shock performance by allowing the spring to twist during high deflection and helping to prevent the preload ring from self-adjusting due to coil windup.

The Sprindex coil is designed to fit the largest diameter shocks (Rockshox) without an adaptor but it’s still recommended to use the Performance adaptor to increase the shock’s performance and to help prevent preload self-adjustment. All other shocks MUST be run with the correct adaptor to remove any unnecessary play. Fox shocks should use both the standard aluminium adaptor ring AND the Sprindex Performance Adaptor.

Colour and Finish: Black gloss spring with a grey Sprindex adjustment assembly.

What’s in the box: Spring, adjuster, 5 Delrin Performance Adaptors to suit different brand shocks.

Choosing the right Sprindex: Consider which of these categories you fall into.

1. Your current coil seems a little too stiff and you are not quite getting full travel. Choose a Sprindex with the highest end of the range at or just below your current coil. For example, if your current coil is 450, choose about a 400-450 Sprindex.
2. Your current coil seems a little too soft and you occasionally bottom out. Choose a Sprindex with the lowest end of the range at or just above your current coil. For example, if your current coil is 450, choose about a 450-500 Sprindex.
3. Your current coil is way too stiff. Choose a Sprindex with the highest end of the range around 25 to 50 below your current coil. For example, if your current coil is 450, choose about a 350-400.
4. Your current coil is way too soft. Choose a Sprindex with the lowest end of the range around 25 to 50 above your current coil. For example, if your current coil is 450, choose about a 500-550.
5. Your current coil seems to be very close to your ideal for most riding conditions. Choose a Sprindex with your current coil rate somewhere towards the middle of the Sprindex range.