Playing with Spring Lengths - Main and Secondary

wesinls

wesinls

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Most of the Sand Rails look to have equal lengths of the main and secondary springs, but most of the more modern side by sides have a difference. 

In example, my buggy bas two 14 inch springs in the rear.

Where the Can-Am has a 20 inch and a 12 inch in the rear.

There's not much info out there on this topic that I could find, curious if anyone has dealt with this or played with spring lengths on their buggy...going from equal lengths to mixing it up a bit.  I know I know, call shock therapy, call builder, etc - but wondering if anyone on here has first-hand experience. 

 
I would call Schmidty racing before I called the other people... 

 
I have different lengths on mine. 
I couldn’t get the ride height I wanted with equal lengths.
So my uppers are 2” shorter than lowers. 

Most sand rails are over sprung IMO. 

 
Given that's an old Alumicraft, I'd try to find out what Cooley's thoughts are on this.

 
lincster said:
I have different lengths on mine. 
I couldn’t get the ride height I wanted with equal lengths.
So my uppers are 2” shorter than lowers. 

Most sand rails are over sprung IMO. 
Click to expand...
So true. Every car I’ve ever had I’ve had to lower the spring rates by a lot. 

 
It’s mainly to get the ride height and crossover position you want. A longer spring will also be softer, so it could just be a cost cutting measure to use the same wire for both springs. 

If you’re happy with the overall rates, ride height and crossover location, no need to fack with it. :biggrin:

 
This is a great topic and I just went from a 2seat LS to a 4 seat LS. Same shocks, way different outcome. Not only did I learn the ride height angle was different but that my top spring was way long and soft. Sure it rode super soft on the slow stuff but I imagine I was getting coil bind before crossover hits. It was a 18" 275lb over a 16" 400lb on a 16" Shock. Now I'm at 350lb 14" over the same 400lb 16". I have yet to see what it's going to do, but it's much better than my soft spring because on this car, it damn near compressed like 70%.

 
Length of spring will not make it softer. The spring rates are linear for all of the springs we use on the buggy, meaning the rate is for every inch of compression no matter how long or short the spring is. The main reason for the unequal length springs is to overcome a potential for coil bind of the lower spring after crossover. Crossover is the point at which the spring slider hits the crossover collar. If there is more travel left in the shock than the space between each coil of the lower spring (added together), it will go to coil bind and break the slider. I agree with most that a lot of cars are over sprung and it is because the springs are being used to do what the shock valving and bypass tubes should be doing. 

 
Mike E said:
Length of spring will not make it softer. The spring rates are linear for all of the springs we use on the buggy, meaning the rate is for every inch of compression no matter how long or short the spring is. The main reason for the unequal length springs is to overcome a potential for coil bind of the lower spring after crossover. Crossover is the point at which the spring slider hits the crossover collar. If there is more travel left in the shock than the space between each coil of the lower spring (added together), it will go to coil bind and break the slider. I agree with most that a lot of cars are over sprung and it is because the springs are being used to do what the shock valving and bypass tubes should be doing. 
Click to expand...
Yeah, I should've been more accurate: a spring using longer wire will be softer for the same wire diameter.  

 
Last edited by a moderator:
FWIW I purchased internal bypass fox shocks with rebound adjustments on the shafts - but they are side by side shocks...fox doesn't make internal bypass offroad shocks with rebound adjustments nor do they make a front internal bypass shock in offroad that are the correct dimensions for my buggy...people would say just valve shocks for rebound etc, but having the adjustability on the shock itself to me seemed like a better route.

This PDF from fox, if you scroll to the bottom, has all the dimensions on the individual shocks...for the fronts and rear shocks in my case, all dimensions were within a 1/4 inchish.  3.0 internal bypass for the rear and 2.5 internal bypass for the fronts.

FOX_UTV_APP-GUIDE.pdf (ridefox.com)

This is what's led me to the spring questions...I'm going to most likely use the spring length combo used on the particular shock I went with, but adjust weights for my car.

Hoping for the best, it's an expensive gamble that I hope pays off. 

 
wesinls said:
FWIW I purchased internal bypass fox shocks with rebound adjustments on the shafts - but they are side by side shocks...fox doesn't make internal bypass offroad shocks with rebound adjustments nor do they make a front internal bypass shock in offroad that are the correct dimensions for my buggy...people would say just valve shocks for rebound etc, but having the adjustability on the shock itself to me seemed like a better route.

This PDF from fox, if you scroll to the bottom, has all the dimensions on the individual shocks...for the fronts and rear shocks in my case, all dimensions were within a 1/4 inchish.  3.0 internal bypass for the rear and 2.5 internal bypass for the fronts.

FOX_UTV_APP-GUIDE.pdf (ridefox.com)

This is what's led me to the spring questions...I'm going to most likely use the spring length combo used on the particular shock I went with, but adjust weights for my car.

Hoping for the best, it's an expensive gamble that I hope pays off. 
Click to expand...
I did the same thing for my project. Got a set of FOX rebound/compression adjustable from a CanAm. Once the project is complete I'll 4-corner weight it and change the spring rates, then once driving/testing I'll have them revalved too.
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