Tool-free spring rate adjustment is coming to coil shocks, thanks to Sprindex. The new coil spring system allows riders to fine tune their coil spring rate, instead of having to switch between coils to get the correct spring rate.
Sprindex is backed by freeride legend Richie Schley and original Crankbrothers founders (Carl Winefordner, Frank Hermansen, Andrew Herrick). The company was born out of its founders collective frustration that the limited adjustability of coil suspension was holding them back from the performance benefits of coil.
Coil-sprung shocks once dominated the mountain bike industry. The last decade, though, has been all about air-sprung shocks that are lighter, and more easily adjustable. Many riders would agree that, weight penalty aside, coil shocks provide better performance than air shocks.
Sprindex is looking to solve at least one limitation of coil, by making spring rate adjustable without having to change springs.
How does it work? In Sprindex’s words:
“Spring rate is determined by 4 factors: wire diameter, coil diameter, material, and number of active coils. Fewer active coils makes for a stiffer spring. Twisting the Sprindex adjustment dial varies the number of active coils. Adjustment is done by hand and without tools.”
Effectively, twisting the Sprindex adjustment dial incrementally locks out sections of the coil spring, changing spring rate instead of adjusting preload. This allows for more fine tune adjustment than the usual 50 lb/in, or 25 lb/in differences between different coil springs.
Sprindex is available for an extensive list of current coil shocks. You can see the very long compatibility chart on Sprindex’s website.
Sprindex retails for $140.00 USD. It is available at local bike retailers and through Sprindex.com.