In May 2015, Hyperco released a limited production of a 14” free length spring with 2.5” end ID’s and a dual rate of 200lb/in transitioning to a secondary rate of 425lb/in. The rate transition started at 625lb of spring load and was complete by 800-825lb of spring load. The part number of this spring is 14B0200/425UHT.

Initially intended for the left rear of pavement late-models running on medium banked tracks, the 14B0200/425UHT quickly found favor on the right front (as well as other locations) of Dirt Late-Models running in series where spring stacking was outlawed. This spring features an extremely linear 200lb/in rate through the first 3.125” of deflection (approximately 625lb of spring load) at which time the rate transitions to the rate through a transition range of 0.750”- 1.00”. Rate transition is completed by the time the spring load rises to 800-825lb, and is fairly linear until coil bind.

The light rate section of the spring is characterized by closely wound coils and the higher rate by wider spaced coils. The wide coil spacing provides excellent opportunity for tuning the second rate with spring rubbers.

In discussions with many racers and chassis builders running in various series; we decided we needed additional variations on this theme; so for 2016 we are offering three additional springs in this line-up:

  • 12B0175/350UHT 12” free length with a 175lb/in initial rate and 350lb/in secondary rate
  • 12B0200/425UHT 12” free length with a 200lb/in initial rate and 425lb/in secondary
  • 14B0175/350UHT 14” free length with a 175lb/in initial rate and 350lb/in secondary rate

These three new springs all have the transition point start at 625lbs and completed in the 800-825lb load range. All springs in this family are built in an “understressed” condition so the closely wound coils can live at coil bind indefinitely without taking set.

NOTE: Hyperco Dual-Rate springs are not Progressive Rate springs. Progressive rate springs have rates that constantly increase as deflection increases. This makes shock valving extremely difficult if not impossible. Hyperco Dual-Rate springs have two distinct linear rate areas connected with a known transition zone. This allows accurate shock tuning because you know what amount of deflection is required to get to the transition point and the width of the transition range. This is a huge advantage in shock tuning.

The 12B0175/350UHT is currently available for shipping. The 12B0200/425UHT and 14B0175/350UHT will be ready for shipping by 4/25/16 if not sooner.

We are ready for the demand for these innovative new springs with a large inventory of all four part numbers. Let’s all have a great 2016!


Dual Rate Spring Design Specifications