Not every upper spring does the same job.
Before comparing tender spring kits, separate the spring’s name from what it does in your shock assembly. This page explains the mechanics; our All Thingz UTV buyer’s guide handles model and kit selection.
Tender springs vs. helper springs
A helper has a very low rate and mainly keeps the main spring seated at full extension. An active tender contributes to the combined spring rate. A factory spring described as a tender may behave more like a helper at normal ride height. Check the actual assembly.
How two springs work together
For two active linear springs in series, the combined rate is (k1 × k2) ÷ (k1 + k2). For example, 200 and 400 lb/in produce about 133 lb/in together. This is an illustration, not a recommended rate for your UTV.
What changes at the crossover?
A crossover can stop further upper-spring compression. Some designs instead transition when that spring reaches its designed block height. The main spring then sets the spring rate. Two linear stages are not the same as a continuously progressive spring.
See Eibach’s spring-system explanation for the helper, tender and transition distinctions.
Spring rate, preload and damping are different
Spring rate describes force per unit of spring compression. Preload is the compression applied at the assembly’s reference position; adding preload does not change the rate of a linear spring. Damping controls suspension motion. Adjustments should follow the instructions for the specific shocks and kit.
What this means when shopping
- Check whether the kit replaces only the tenders or also the main springs.
- Confirm the supported chassis and installed shocks.
- Use the specified hardware and setup procedure.
- Do not diagnose spring failure from a compressed upper spring alone.
Riley recommends All Thingz tender springs for the noticeably more plush ride. His experience helps explain the recommendation; the correct application and setup make it relevant to your machine.
Compare XP 1000 kits, Turbo R kits, and Xpedition kits. Need help preparing for the work? Read our installation and adjustment guide.
Call 801-899-2520 with your year, full model, seat count and shock information. We’ll help you choose your All Thingz UTV tender spring kit.