Spring Rates

[GrayWolf.Overland]

interesting... I've read that the JKS 1.5" is 130 in the front... slightly higher than the 2.5"-3.5". I Really wish companies would stop trying to hide this info.

Yeah I expected them to be higher too, the info I got is from their tech support team responding to an email I sent asking them for info on spring rates and shock valving.
I was leaning towards getting that kit, now I am not too sure.. I find the 160-front springs from Clayton plush and wont call it firm, so I might go with Clayton again when moving to 2.5 springs

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[AnnDee4444]

When we talk about spring rates, are we talking about the spring rate* (also called the spring constant) in Hooke's Law: F = -kx? Of course assuming non-dual/triple rate springs.

Correct. Rates given are how many pounds it takes to compress the spring 1" (lb./in.). Another common unit of measurement is kg/mm, but I've never seen Jeep springs with metric units.

If so, would that mean that two springs of the same rate would compress (x in the above) the same amount to the same static load regardless of other factors like unsprung length or number of coils?

Assuming the spring isn't binding or beyond it's free length, this is exactly correct.

While wire diameter/material & number of coils influence the spring rate, you can have two springs manufactured completely different from each other end up with the same rate... and they can be assumed to perform identically until their limits of their operation.

 

[OminousSkitter]

Thanks! I was thinking (and hoping) that to be the case. It lets me know the original lift I'm considering might not help fix the issue I'm having and I might need to find springs with a higher rate—either that or my rear springs are shot.

 

[AnnDee4444]

Thanks! I was thinking (and hoping) that to be the case. It lets me know the original lift I'm considering might not help fix the issue I'm having and I might need to find springs with a higher rate—either that or my rear springs are shot.

I know some people will disagree, but I don't see anything wrong using spacers to level the front/back if you don't need/want a higher spring rate.

 

[OminousSkitter]

I know some people will disagree, but I don't see anything wrong using spacers to level the front/back if you don't need/want a higher spring rate.

I have no problem with leveling it with spacers. Mind if I start a new thread with my current setup and problems (to keep this about spring rates) and tag you?

 

[GrayWolf.Overland]

I know some people will disagree, but I don't see anything wrong using spacers to level the front/back if you don't need/want a higher spring rate.

Yep this is true. I started out with the Clayton 1.5 and my front currently sits with an additional 1" teraflex spacer to account for lift lost after a year of settling and steel bumper + winch
The ride quality is just the same as its still leveraging the same spring rate albeit sitting on top of a 1" puck.

 

[AnnDee4444]

I have no problem with leveling it with spacers. Mind if I start a new thread with my current setup and problems (to keep this about spring rates) and tag you?

 

[GrayWolf.Overland]

interesting... I've read that the JKS 1.5" is 130 in the front... slightly higher than the 2.5"-3.5". I Really wish companies would stop trying to hide this info.

I circled back with them again and asked them to state both rates on their progressive coil. I update my table with the latest info from JKS. Sounds like JKS standard is plush riding and in the same ballpark as Synergy. JKS HD springs are very similar to Clayton's

JKS	2.5"/3.5"	110 / 175 (progressive)	144 / 210 (progressive)
JKS	2.5"/3.5" HD	144 / 210 (progressive)	152 / 210 (progressive)

 

[AnnDee4444]

I circled back with them again and asked them to state both rates on their progressive coil. I update my table with the latest info from JKS. Sounds like JKS standard is plush riding and in the same ballpark as Synergy. JKS HD springs are very similar to Clayton's

JKS	2.5"/3.5"	110 / 175 (progressive)	144 / 210 (progressive)
JKS	2.5"/3.5" HD	144 / 210 (progressive)	152 / 210 (progressive)

Interesting that the heavy duty only starts at +8 lb/in more in the rear, ending in the exact same rate as the standard springs... but the fronts heavy duty is very different.

 

[GrayWolf.Overland]

TIL Teraflex Front HD 3.5 springs are 170 lb/in linear

@AnnDee4444 - thats for the last row in your sheet. HD rates for teraflex are not filled in

 

[Fast-n-Furious]

Thanks for the data! I'm looking into spring rates recently, targeted the Clayton 392 performance coils, which essentially is a combination of their JL 1.5" rear coils + JK/JL/JT 2.5" front coils.

Thanks a lot to @GrayWolf.Overland for correcting my misunderstanding on the dual spring rates. More details at https://www.jlwranglerforums.com/fo...ks-springs-experts.121642/page-2#post-2535016

 

[GrayWolf.Overland]

Updates - Clayton HD Springs, Teraflex HD Springs

Manufacturer	Option/Variant	Front lb/in	Rear lb/in
Jeep	JLU Sport	117	172
Jeep	JLU Rubicon	125	174
Jeep	Mopar 2" Lift	132	181
Teraflex	2.5"/3.5"	140	170
Teraflex	2.5"/3.5" HD	170	300
Clayton	1.5"	160	137 / 200 (dual rate)
Clayton	2.5"/3.5"	188	165 / 230 (dual rate)
Clayton	2.5" HD	N/A	165 / 285 (dual rate)
Clayton	3.5" HD	N/A	170 / 285 (dual rate)
Synergy	1"	95 / 120 (dual rate)	115 / 150 (dual rate)
Synergy	2"/3"	110 / 120 (dual rate)	140 / 175 (dual rate)
Synergy	4"	115 / 120 (dual rate)	120 / 180 (dual rate)
Rock Krawler	2.5"	137	175
Rock Krawler	3.5"	140	185
JKS	2.5"/3.5"	110 / 175 (progressive)	144 / 210 (progressive)
JKS	2.5"/3.5" HD	144 / 210 (progressive)	152 / 210 (progressive)
OME	2-2.5" Standard	135	160
OME	2-2.5" Medium	150 (bumper + Winch)	175
OME	2-2.5" Heavy	170	200

 

[Seemego4WD]

Anyone have spring rates for the aev 2.5 and 3 inch.

 

[AnnDee4444]

Anyone have spring rates for the aev 2.5 and 3 inch.

I haven't seen rates published but I do know they claim to be triple-rate.

 

[daverockville]

We have posted it in a few other threads so here's a copy and paste from that, the first few lines refer to stock springs, then our springs:

“JLU Sport - 114/121 Front 171/174 Rear

JLU Rubicon - 123/128 Front 172/176 Rear

Mopar 2" Coils Lift - 131/133 Front 180/182 Rear

Our 2.5" Coil Spring Rates are as follows in the ride zone

137.5 Front at Ride Height

175 Rear at Ride Height

3.5" Coils are already coming in so we will give you those too

140 Front at Ride Height

185 Rear at Ride Height

The stock coils were dyno'd in house as well as at our spring supplier for confirmation of accuracy of rates."

Nice work! I have a 2024 Jeep Wrangler Rubicon X (3.6L) with extreme recon (35s) from factory. Looking at upgrading due towing. Do you know what are the values for the front and back springs for my configuration?

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