Dual-Rate Spring Kit

I have recently installed a dual-rate spring kit on a Polaris UTV and would like to give some explanation of what it helped and why you would want this type of suspension upgrade.

If you are into side x sides and have had conversations with other riders or your professionals who work service and build these high fast-flying UTV’s, or maybe you are like me, just looking to get a better ride. If so, after a full day of riding and having a blast, you don’t have to get my walker to help me out of my UTV.

If you want a better ride quality out of your UTV or, in my case, make my wife and passengers happy to take a ride with me, you best think coil springs – because this is where it is at!

Most side x sides from the factory come with a nice set of shocks and usually have a single mainspring and might have a tender spring on top. Don’t confuse this tender spring as a dual-rate spring, because it is not. The tender spring’s job is to keep everything in its place when you leap off that hill and the suspension goes into droop – you don’t want the mainspring jumping out of its seat pockets.

So, now I will give you an explanation of why you get a better ride when a dual-rate spring set is installed on your high- end shock absorbers.

I will give the example of the most recent spring kit installed on a Polaris. In order to understand what the dual-rate kit will do, you need to know what your original springs were.  It goes right along with, if you don’t know where you are, then how do you know how to get where you are going.

The original weight springs on this Polaris were:

Front Main Springs300 LBS.
Rear Main Springs205 LBS.

These are the springs that are taking all the pressure from the bumps, rocks, hits, G-outs.

As you can see, it does not matter if it is a small bump or a large bump. The front end is hitting 300 lbs. force on both sides – small or large it is the same.

The rear is hitting at 205 lbs. Small or large bumps this is what you get.

So, with the one spring, the spring has to accommodate small or large bumps so the manufacture installs a middle ground to try and please everyone’s ride style. So, this is when I read about people talking about how junk the original springs are.  This is not always the case. The springs just might not work for your riding style or the middle ground just isn’t good enough for a comfortable ride along with the big hits.

 

Now let’s take a look at the dual-rate spring kit just installed in place of the above springs:

Front lower main spring weight rating350 LBS.
Front upper spring weight rating 535 LBS.
Rear lower main spring weight rating 240 LBS.
Rear upper spring weight rating 190 LBS.

Now we need to know how the dual-rate spring gets a separate rating and here is the formula for figuring this out.

Lower spring X Upper spring ÷ by Lower spring + Upper spring.

Front spring formula

350 X 535 = 187,250

350 + 535 = 885

187,250 ÷ 885 = 212 rounded up

Rear spring formula

240 X 190 = 45,600

240 + 190 = 430

45,600 ÷ 430 = 106 lbs.

Dual-Rate Springs

Dual-Rate Springs Fox Shock Polaris XPT

Dual-Rate Spring Kit

Polaris RZR 900 Fox 2.0 Dual-Rate UTV Spring Kit

Here is how it looks like on spring ratings now:

Front springs, while in small bumps before, engage the crossover rings hitting the bottom spring. It will be hitting at 212 lbs. instead of the original 350 lbs.

Once you hit a larger g-outs and the crossover ring makes contact with the lower mainspring, it will be hitting at 350 lbs. instead of the original 300 lbs.

Rear springs, while in small bumps before, engages the crossover rings hitting the bottom spring.  It will be hitting at 106 lbs. instead of the original spring 205 lbs.

Once you hit a larger g-outs and the crossover ring makes contact with the lower mainspring, it will be hitting at 240 lbs. instead of the original 205 lbs.

After looking at these tables and figures, you can see now that we will, for sure, have a better ride.  While hitting the small bumps, it is riding on softer springs than the originals. When we hit the large springs, there will be a good chance of bottoming out, so we will be using a stiffer spring than the original spring rating.

Don’t forget you will have to get these set up correctly to take full advantage of them.  This includes getting your proper ride height along with adjusting the crossover rings to make sure they are utilizing the dual-rate exactly the way you want them to.

This is the one suspension upgrade that you will notice the most difference in ride quality, and if you read and understand this article it makes for easy proof in the numbers.

If UTV Service can help you get your upgrade on your springs please give us a call.

Until we ride again.