By KevinP on Thursday, March 22, 2001 - 04:05 am: Edit

What is the difference if any between a dual rate or a progressive spring ?

By Troy on Thursday, March 22, 2001 - 05:20 am: Edit

From my understanding, a dual rate spring is a progressive spring. A spring maker, by adjusting either the wire diameter, average wire diameter throughout the spring, or the number of coils, can increase or decrease the spring rate. Though most coils only have one rate througout the entire spring, by adjusting wire diameter and/or the # of coils in a given spring, a spring maker can make a spring that has 2 or more rates.
Troy

By Clint on Thursday, March 22, 2001 - 07:39 am: Edit

They are probably close to the same thing.

A dual rate spring may be composed of two stacked springs each with a different rate. Many coil-over shocks use this techique.

A progressive spring is a single spring that has unevenly spaced coils. This gives it a spring rate that increases as it compresses.

Clint