Sprindex Adjustable-Rate Coils Allow Mountain Bikers to Quickly Tune Their Spring Rate

It seems like every season another suspension manufacturer comes online with the latest coil-sprung shock, guaranteeing unprecedented ground-hugging rear tire traction. In addition to the two largest brands, there are fantastic options from Extreme Racing, MRP, Push, DVO, X-Fusion, Cane Creek, Öhlins, Fast Suspension, and others. The only suspension brands we could think up that are not producing a modern coil shock are Formula, Manitou, and SunTour, and it’s a good bet that they too have something springy in the works.

Coil shocks are loved by mountain bikers around the world for their lack of stiction, traction providing prowess, and consistent ride feel regardless of weather conditions or descent length. Their faults include some added weight, occasionally inadequate spring rate options, and the cumbersome task of swapping springs between different rides or riders. While most linear spring lovers can deal with the extra grams, adjustability has forever been the bane of the coil. It’s like having an air shock that can only be pumped up to one precise pressure, regardless of the day’s trail or the rider’s evolving riding style. The folks at Sprindex have stepped in to fix that issue.

The company’s patent-pending coil system allows riders to adjust their spring-rate by 30-60 lb/in, depending on the model. Adjustments can be made by clicking between 5 lb/in increments, in a matter of seconds, without the use of a single tool.

With most shock manufacturers offering coils in 25 or 50 lb/in increments, the Sprindex coil allows coil-lovers to tune their spring rate far more precisely. The shock can now be adjusted for a slightly heavier or lighter friend who wants to try your bike, for fluctuations in your own weight or the weight of your gear, for the type of terrain you will be riding, or to more closely dial in the sag on a coil equipped bike.

How does Sprindex adjust spring rate?

Preload exists to take play out of the coil shock system, and should not be used to adjust sag. For that, we need a different spring rate. Gone are the days of sacrificing traction by adding too much preload to artificially set a bike’s sag. With this adjustable system, we can all sag properly. According to Sprindex, “Spring rate is a function of four characteristics: wire diameter, coil diameter, material, and the 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.” In short, it reduces the number of useable coils for a stiffer shock, or increases them for a softer one.

For riders who are coil curious, this contraption could be a great way to test out a coil-sprung shock without losing the adjustability of your air system. For die hard coil-lovers, the Sprindex is likely what you were already asking for, and you can order it up for $140 at your local dealer.