Dual rate springs: JKS JSPEC dual rate versus Metalcloak dual rate

[Fargo]

You are still operating under the misguided assumption that the custom tuner knows or cares what the spring rate is. If they aren't asking me what it is, what does that mean?

That may just be poorly worded on my part. The tuner wouldn't need to know what the rate is. The rate is whatever it is. I would expect the tuner would be more concerned about vehicle weight and performance requirements. I've never tuned a shock so correct me if I'm wrong.

 

[Fargo]

How confident are you that your springs are really dual rate and not just dual wound? There is a difference. And to the best of my knowledge, there are no commonly available dual rate aftermarket coils available for the TJ.

You can confirm yours with a caliper by measuring the wire thickness across the length of the spring.

As I understand it, different windings will effectively give a different rate. Its a matter of leverage and the length of rod used to make the coil. You can easily test it by compressing the spring. The tighter wound coils will compress under less weight than the further space out coils.

Here is some info from a spring manufacturer. Take it as you will:
https://www.hypercoils.com/tech-tips/linear-vs-progressive-rate-suspension-springs/

The second type of progressive rate suspension springs, the dual-rate spring with two linear rates connected with a rate transition range is a much more sophisticated suspension spring. The design is much more focused on the specific use for the spring. These types of springs are used primarily in road racing and high performance street and GT applications where the vehicle trim package will stay in a very predictable range. These springs are easily identified by having a few closely wound coils at one end and then wider, equal spaced coils at the other end. They have rates described as 200/425lb/in. This means that the spring has an initial rate of 225lb/in through some range of deflection and then the rate transitions to 425lb/in through a deflection range of 1”-1.5.” The big advantage of these springs is that they can provide “roll control” in addition to roll control provided by sway bars.


Let’s discuss roll control provided by springs. For “linear rate springs” the discussion is easy. They provide no roll control! Think about taking curve at a very high speed. The side of the car on the outside of the turn rolls over and the side of the car on the inside tends to roll up. For discussion sake, let’s assume we have 300lb/in linear rate springs on the front of our car and the car is rolling too much and cornering speed suffers. If we move up to a set of 400lb/in springs in an attempt to “stiffen” the suspension, we fail because the linear rate springs provide no roll control. Think about it. As you enter the same curve at the same speed your vehicle is rolling onto a higher rate spring; BUT the inside of the vehicle is being pushed up by a higher rate spring, also. So there is not improvement with roll control. With linear rate springs, all roll control must come from the sway bar (anti-roll bar).


With properly designed progressive rate springs, we can have the springs contribute to the roll control of the vehicle. The key here is to have the vehicle sit in the rate transition range at curb ride height with the designed number of passengers in the vehicle. For racing applications, this is usually one person of a known weight. For GT and high-performance driving this is usually two people of approximately 180lb each and a full tank of fuel.


When the vehicle sits in the rate transition point, the closely wound coils will be closed almost to the solid point. This often necessitates the use of rubber or synthetic coil covering on one or more of the closely wound coils to minimize noise when the coils go solid. Let’s assume we are working with a 200/425lb/in spring. At ride height we will be sitting on the low end of the rate transition range, about 210lb/in. As we enter a high speed turn, the outside of the vehicle will roll into the 425lb/in spring rate and the inside of the vehicle will be pushed up with a much lighter 200lb/in rate. This provides a significant improvement in roll control. The use of a sway bar will supplement roll control and can provide a more focused level of suspension tuning.

 

[mrblaine]

As I understand it, different windings will effectively give a different rate. Its a matter of leverage and the length of rod used to make the coil. You can easily test it by compressing the spring. The tighter wound coils will compress under less weight than the further space out coils.

Here is some info from a spring manufacturer. Take it as you will:
https://www.hypercoils.com/tech-tips/linear-vs-progressive-rate-suspension-springs/


View attachment 324334


The second type of progressive rate suspension springs, the dual-rate spring with two linear rates connected with a rate transition range is a much more sophisticated suspension spring. The design is much more focused on the specific use for the spring. These types of springs are used primarily in road racing and high performance street and GT applications where the vehicle trim package will stay in a very predictable range. These springs are easily identified by having a few closely wound coils at one end and then wider, equal spaced coils at the other end. They have rates described as 200/425lb/in. This means that the spring has an initial rate of 225lb/in through some range of deflection and then the rate transitions to 425lb/in through a deflection range of 1”-1.5.” The big advantage of these springs is that they can provide “roll control” in addition to roll control provided by sway bars.


Let’s discuss roll control provided by springs. For “linear rate springs” the discussion is easy. They provide no roll control! Think about taking curve at a very high speed. The side of the car on the outside of the turn rolls over and the side of the car on the inside tends to roll up. For discussion sake, let’s assume we have 300lb/in linear rate springs on the front of our car and the car is rolling too much and cornering speed suffers. If we move up to a set of 400lb/in springs in an attempt to “stiffen” the suspension, we fail because the linear rate springs provide no roll control. Think about it. As you enter the same curve at the same speed your vehicle is rolling onto a higher rate spring; BUT the inside of the vehicle is being pushed up by a higher rate spring, also. So there is not improvement with roll control. With linear rate springs, all roll control must come from the sway bar (anti-roll bar).


With properly designed progressive rate springs, we can have the springs contribute to the roll control of the vehicle. The key here is to have the vehicle sit in the rate transition range at curb ride height with the designed number of passengers in the vehicle. For racing applications, this is usually one person of a known weight. For GT and high-performance driving this is usually two people of approximately 180lb each and a full tank of fuel.


When the vehicle sits in the rate transition point, the closely wound coils will be closed almost to the solid point. This often necessitates the use of rubber or synthetic coil covering on one or more of the closely wound coils to minimize noise when the coils go solid. Let’s assume we are working with a 200/425lb/in spring. At ride height we will be sitting on the low end of the rate transition range, about 210lb/in. As we enter a high speed turn, the outside of the vehicle will roll into the 425lb/in spring rate and the inside of the vehicle will be pushed up with a much lighter 200lb/in rate. This provides a significant improvement in roll control. The use of a sway bar will supplement roll control and can provide a more focused level of suspension tuning.

You're still talking about springs like it matters, it really doesn't, stop it.

 

[jjvw]

As I understand it, different windings will effectively give a different rate. Its a matter of leverage and the length of rod used to make the coil. You can easily test it by compressing the spring. The tighter wound coils will compress under less weight than the further space out coils.

Here is some info from a spring manufacturer. Take it as you will:
https://www.hypercoils.com/tech-tips/linear-vs-progressive-rate-suspension-springs/


View attachment 324334


The second type of progressive rate suspension springs, the dual-rate spring with two linear rates connected with a rate transition range is a much more sophisticated suspension spring. The design is much more focused on the specific use for the spring. These types of springs are used primarily in road racing and high performance street and GT applications where the vehicle trim package will stay in a very predictable range. These springs are easily identified by having a few closely wound coils at one end and then wider, equal spaced coils at the other end. They have rates described as 200/425lb/in. This means that the spring has an initial rate of 225lb/in through some range of deflection and then the rate transitions to 425lb/in through a deflection range of 1”-1.5.” The big advantage of these springs is that they can provide “roll control” in addition to roll control provided by sway bars.


Let’s discuss roll control provided by springs. For “linear rate springs” the discussion is easy. They provide no roll control! Think about taking curve at a very high speed. The side of the car on the outside of the turn rolls over and the side of the car on the inside tends to roll up. For discussion sake, let’s assume we have 300lb/in linear rate springs on the front of our car and the car is rolling too much and cornering speed suffers. If we move up to a set of 400lb/in springs in an attempt to “stiffen” the suspension, we fail because the linear rate springs provide no roll control. Think about it. As you enter the same curve at the same speed your vehicle is rolling onto a higher rate spring; BUT the inside of the vehicle is being pushed up by a higher rate spring, also. So there is not improvement with roll control. With linear rate springs, all roll control must come from the sway bar (anti-roll bar).


With properly designed progressive rate springs, we can have the springs contribute to the roll control of the vehicle. The key here is to have the vehicle sit in the rate transition range at curb ride height with the designed number of passengers in the vehicle. For racing applications, this is usually one person of a known weight. For GT and high-performance driving this is usually two people of approximately 180lb each and a full tank of fuel.


When the vehicle sits in the rate transition point, the closely wound coils will be closed almost to the solid point. This often necessitates the use of rubber or synthetic coil covering on one or more of the closely wound coils to minimize noise when the coils go solid. Let’s assume we are working with a 200/425lb/in spring. At ride height we will be sitting on the low end of the rate transition range, about 210lb/in. As we enter a high speed turn, the outside of the vehicle will roll into the 425lb/in spring rate and the inside of the vehicle will be pushed up with a much lighter 200lb/in rate. This provides a significant improvement in roll control. The use of a sway bar will supplement roll control and can provide a more focused level of suspension tuning.

I've actually done that and measured it years ago on a set of Currie 3" coils. Unlike your 200/425 example, this was something we can actually use on a TJ. It's a very small difference in rate between fully active coils and when the tightly wound section becomes solid. I suspect these dual wound springs, when implemented properly for our application have far more to do with creating a stable spring with a suffiently long free length for the application. Currie/RockJock being examples of this. Metalcloak and RockKrawler being the parody.

Meaning that the reason for a dual (triple, quadruple) wound spring on a TJ is not what you think it is for.

 

[mrblaine]

I've actually done that and measured it years ago on a set of Currie 3" coils. Unlike your 200/425 example, this was something we can actually use on a TJ. It's a very small difference in rate between fully active coils and when the tightly wound section becomes solid. I suspect these dual wound springs, when implemented properly for our application have far more to do with creating a stable spring with a suffiently long free length for the application. Currie/RockJock being examples of this. Metalcloak and RockKrawler being the parody.

Meaning that the reason for a dual wound spring on a TJ is not what you think it is for.

I put them on a spring dyno, there is naught but a linear rate.

 

[jjvw]

I put them on a spring dyno, there is naught but a linear rate.

I did it by lifting a tire up with a floor jack and measuring the difference in the rate of change between the rising axle pad and the compressing spring. Many things about that could contribute to the apparent rate change I saw. It was small. And it is no surprise to me that a spring dyno would really show a linear rate in a controlled test that isolated the spring.

 

[Fargo]

The JKS front coils are 150/220 the rear coils are 190/240. So a 70lb difference in front and a 50lb difference in the rear. For whatever its worth... It maybe doesn't matter in regards to handling. But that extra 50lbs per spring (x2) gives an extra 100lbs per inch of carrying weight when I load up the LJ. I purchased them for carrying loads, not handling. Any handling improvement is a bonus. I should have been more clear before the discussion got side tracked. As I said before, without testing identical rigs on a skidpad, its really not possible to claim handling benefits. So I won't argue that point other than to say in theory its possible. In reality, as Mr Blaine said, it doesn't matter.

For me, I liked the dual rate to carry the extra load. I mentioned shock choice only because it worked well on my rig with those coils sitting at the advertised 3" of lift. If another rig is similar in weight to mine, it should have similar results. If your lighter or heavier all bets are off.

 

[mrblaine]

The JKS front coils are 150/220 the rear coils are 190/240. So a 70lb difference in front and a 50lb difference in the rear. For whatever its worth... It maybe doesn't matter in regards to handling. But that extra 50lbs per spring (x2) gives an extra 100lbs per inch of carrying weight when I load up the LJ. I purchased them for carrying loads, not handling. Any handling improvement is a bonus. I should have been more clear before the discussion got side tracked. As I said before, without testing identical rigs on a skidpad, its really not possible to claim handling benefits. So I won't argue that point other than to say in theory its possible. In reality, as Mr Blaine said, it doesn't matter.

For me, I liked the dual rate to carry the extra load. I mentioned shock choice only because it worked well on my rig with those coils sitting at the advertised 3" of lift. If another rig is similar in weight to mine, it should have similar results. If your lighter or heavier all bets are off.

You're still talking about springs.

 

[Fargo]

You're still talking about springs.

I'm not sure I follow where your going. Please elaborate.

 

[psrivats]

As I understand it, different windings will effectively give a different rate. Its a matter of leverage and the length of rod used to make the coil. You can easily test it by compressing the spring. The tighter wound coils will compress under less weight than the further space out coils.

Here is some info from a spring manufacturer. Take it as you will:
https://www.hypercoils.com/tech-tips/linear-vs-progressive-rate-suspension-springs/


View attachment 324334


The second type of progressive rate suspension springs, the dual-rate spring with two linear rates connected with a rate transition range is a much more sophisticated suspension spring. The design is much more focused on the specific use for the spring. These types of springs are used primarily in road racing and high performance street and GT applications where the vehicle trim package will stay in a very predictable range. These springs are easily identified by having a few closely wound coils at one end and then wider, equal spaced coils at the other end. They have rates described as 200/425lb/in. This means that the spring has an initial rate of 225lb/in through some range of deflection and then the rate transitions to 425lb/in through a deflection range of 1”-1.5.” The big advantage of these springs is that they can provide “roll control” in addition to roll control provided by sway bars.


Let’s discuss roll control provided by springs. For “linear rate springs” the discussion is easy. They provide no roll control! Think about taking curve at a very high speed. The side of the car on the outside of the turn rolls over and the side of the car on the inside tends to roll up. For discussion sake, let’s assume we have 300lb/in linear rate springs on the front of our car and the car is rolling too much and cornering speed suffers. If we move up to a set of 400lb/in springs in an attempt to “stiffen” the suspension, we fail because the linear rate springs provide no roll control. Think about it. As you enter the same curve at the same speed your vehicle is rolling onto a higher rate spring; BUT the inside of the vehicle is being pushed up by a higher rate spring, also. So there is not improvement with roll control. With linear rate springs, all roll control must come from the sway bar (anti-roll bar).


With properly designed progressive rate springs, we can have the springs contribute to the roll control of the vehicle. The key here is to have the vehicle sit in the rate transition range at curb ride height with the designed number of passengers in the vehicle. For racing applications, this is usually one person of a known weight. For GT and high-performance driving this is usually two people of approximately 180lb each and a full tank of fuel.


When the vehicle sits in the rate transition point, the closely wound coils will be closed almost to the solid point. This often necessitates the use of rubber or synthetic coil covering on one or more of the closely wound coils to minimize noise when the coils go solid. Let’s assume we are working with a 200/425lb/in spring. At ride height we will be sitting on the low end of the rate transition range, about 210lb/in. As we enter a high speed turn, the outside of the vehicle will roll into the 425lb/in spring rate and the inside of the vehicle will be pushed up with a much lighter 200lb/in rate. This provides a significant improvement in roll control. The use of a sway bar will supplement roll control and can provide a more focused level of suspension tuning.

You are making this too complicated for yourself.You are not designing a vehicle from scratch, all you are doing is picking amongst springs that are available in the market.

Instead of thinking about your suspension from spring rate of your coils, think about your desired ride height, compressed and extended lengths of your desired shocks and the overall travel. Once you decide on the ride height and shocks, pair them with springs with the longest** free length you can find that gives you the ride height you want. Unless you have the volume and budget of an OEM, finding (or custom making) a shock that will exactly match the bind and free lengths of your coils (chosen with whatever methodology incl your favorite metric of spring rate) is not straightforward. You might get lucky mixing and matching and come close, but it is easier if you start this looking at the shocks first and thinking about what they do for your ride quality.

There are several threads here that discuss all this in detail, and people compare different brand of shocks and spring free lengths and shock travel. @jjvw's build thread has really excellent information on many aspects on maximizing suspension performance in terms of shock lengths and travel if you want to learn further.

**Note - companies like Currie/Rockjock have already all this figured out

edit - nevermind, you already have decided and have the coils and shocks you desire. I will leave the above just so that someone new to this reading can get some perspective.

 

[Jerry Bransford]

One more saying the same thing... stop worrying about the springs, please don't bring spring rates back into the discussion again as all of that is strictly irrelevant. Carefully read/re-read until you fully understand all of Blaine's comments above, they are the pure truth... not just his personal opinion. Springs control the ride height, shocks control the ride.

 

[jjvw]

The JKS front coils are 150/220 the rear coils are 190/240. So a 70lb difference in front and a 50lb difference in the rear. For whatever its worth... It maybe doesn't matter in regards to handling. But that extra 50lbs per spring (x2) gives an extra 100lbs per inch of carrying weight when I load up the LJ. I purchased them for carrying loads, not handling. Any handling improvement is a bonus. I should have been more clear before the discussion got side tracked. As I said before, without testing identical rigs on a skidpad, its really not possible to claim handling benefits. So I won't argue that point other than to say in theory its possible. In reality, as Mr Blaine said, it doesn't matter.

For me, I liked the dual rate to carry the extra load. I mentioned shock choice only because it worked well on my rig with those coils sitting at the advertised 3" of lift. If another rig is similar in weight to mine, it should have similar results. If your lighter or heavier all bets are off.

The distance of spring travel at ride height between fully active and partially solid is a small distance. Go for a drive without shocks and see if you can perceive the rate change. In addition to that, a simple linearly wound spring that provided the same ride height with a similar free length as your JKS would provide the same function as your current springs. And you wouldn't be trying to attribute any magical features to your boring straight wound linear rate springs because the marketing department isn't trying to make them something they aren't.

 

[Feralkid]

How did this thread start anyway?

Anyway,

My current opinion is,

if u have to ask.... just buy all rock jock stuff and save yourself the head ache attempting to save $300-400 piecing shit together.

 

[jjvw]

....

There are several threads here that discuss all this in detail, and people compare different brand of shocks and spring free lengths and shock travel. @jjvw's build thread has really excellent information on many aspects on maximizing suspension performance in terms of shock lengths and travel if you want to learn further.

**Note - companies like Currie/Rockjock have already all this figured out

The fun part for those who care to follow along for the long haul is that any differences I thought I was finding way back when was done without the perspective of what shocks are capable of doing. Once I had that experience, everything I thought I knew back then changed when I realized the insignificance and likely inaccuracies of my findings of that time.

 

[jjvw]

How did this thread start anyway?

Anyway,

My current opinion is,

if u have to ask.... just buy all rock jock stuff and save yourself the head ache attempting to save $300-400 piecing shit together.

Or just accept what springs really do and choose based on that. Because not everyone wants a 4" spring lift and their are also some who won't build light enough where RockJock 4" is an appropriate option.

 

[psrivats]

The fun part for those who care to follow along for the long haul is that any differences I thought I was finding way back when was done without the perspective of what shocks are capable of doing. Once I had that experience, everything I thought I knew back then changed when I realized the insignificance and likely inaccuracies of my findings.

I used to wonder if there was some level of exaggeration to the claims when it comes to shocks. Then, thanks to a very generous and selfless person, I experienced the same as you in terms of what a good tune can do and how much it can affect the ride quality on our jeeps. And I started seeing the world entirely differently. It changed my worldview for the better and older discussions that I had read before started making way more sense.

 

[jjvw]

I used to wonder if there was some level of exaggeration to the claims when it comes to shocks. Then, thanks to a very generous and selfless person, I experienced the same as you in terms of what a good tune can do and how much it can affect the ride quality on our jeeps. And I started seeing the world entirely differently. It changed my worldview for the better and older discussions that I had read before started making way more sense.

Changes in worldviews are very interesting and very rare with people.

I had to put disclaimers in several older posts in my thread because a few stubborn insufferable assholes around here were holding me to those older more naive statements. Fun times!

 

[Feralkid]

Or just accept what springs really do and choose based on that. Because not everyone wants a 4" spring lift and their are also some who won't build light enough where RockJock 4" is an appropriate option.

In all honesty, jjvw, anyone who doesn’t build their tj in a way that is acceptable to the forum, should be taped to a post and have their bare asses spanked before being shot!

Just sayin

 

[psrivats]

In all honesty, jjvw, anyone who doesn’t build their tj in a way that is acceptable to the forum, should be taped to a post and have their bare asses spanked before being shot!

Just sayin

You forgot your "/s"

 

[Feralkid]

You forgot your "/s"

Omg
Did I mispronoun some person?