Progressive Spring Kit (QM))

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SKU: 55319 Category:


Progressive Spring Kit ARS # 55319 for Quarter Midgets Includes:

1- Concial Spring

1- Washer

1- Travel Indicator

10-Split Washers

The 1” tall conical spring provides a progressive spring rate for the quarter midget chassis. The spring fits over the shaft on the shock and works in conjunction with the main 1 5/8” I.D. spring on the shock.  The compromise of choosing the soft spring rate for corner entry and exit with the need for a stiffer rate to rotate the center of the corner is over!  Now, with the combination of the two springs working together, you can create the best of both spring rates.

When using the dual spring combination on the right rear corner of the chassis, a soft spring rate is created causing grip on corner entry and forward bite on corner exit. The progressive spring allows you to establish another rate for the middle of the corner when the right rear is heavily loaded.  This spring combination is ideal for a chassis that is free on corner entry and exit, but is tight in the middle of the corner.

The progressive spring is an advantage for the right front corner on fast, high banked tracks especially in heavier classes. When the chassis has a tendency to be loaded up hard in the center of the corner and scrub off speed, the progressive spring will allow you to prevent pinning the right front suspension in the middle of the corner.


  1. Remove shock eye and jam nut from shock shaft
  2. Install big washer with inside counter bore against shock body
  3. Install travel indicator
  4. Install conical spring with large side towards the shock body
  5. Re-install jam nut and shock eye on shaft
  6. Install split washers between small end of spring and jam nut to compress spring to desired rate

Starting Point:

Watching the travel indicator on your shock, compress the conical spring 3/8” to 1/2” during racing conditions and tune from that point.


While watching the travel indicator on the shock shaft use the split washer to tune the amount of the progressive spring. Using a pair of needle nose pliers, you can add or remove the split washers quickly to adjust the amount of load on the progressive spring.

Additional information

Weight 0.25 lbs
Dimensions 1 × 1 × 1 in
Progressive Spring Kit

Blue, Orange, Yellow