Brand: Longacre Racing Products
Spring rubbers are a quick and inexpensive way to adjust spring rate. Instead of taking the time to replace springs (or the expense of carrying around a selection of springs), simply install or remove a spring rubber.
The durable, flexible spacer fits between adjacent coils to change their relative movement. The effect is similar to removing one coil, but without changing static ride height. Multiple hardnesses are available for different effects, and stocking a variety of spring rubbers is much cheaper than stocking a range of springs. It's lighter and takes up less space in the trailer, too! With a little testing and a little practice, you will be able to change spring rates predictably during a pit stop to deal with changing track conditions. This makes them very popular in all levels of NASCAR.
This tall rubber fits between coils spaced 1 1/4" apart. It is long enough to fit 5" - 5.5" springs, but it can be cut shorter to fit smaller springs. The Red color quickly identifies it as medium hardness (40 durometer). Other hardnesses are available, including 15 (soft) and 50 (medium-hard) for different rate changes -- the softer the rubber, the smaller the rate change. Depending on the spring, a softer rubber can provide an effective rate that is between the oficially manufactured rates. Sold individually.
Note: The spring rubber is manufactured and shipped as a "donut". You must cut it to create a "C" shape that can be slipped in and out of the spring coils.