BigJ
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Front Stock Fox vs Fox 3.0 vs Icon 3.0 vs King 3.0: Dyno Results
First, the ground rules
1) These results were not derived by me, nor were the tests supervised by me. They were, however, carried out by experts in the field who make their living on producing fair, unbiased, accurate and repeatable results. I will put my name and reputation behind these results as if I had carried out the tests myself. If that's not good enough for you, I encourage you to conduct your own experiments and produce your own results, and to close this thread now. Otherwise read the following with confidence as if I was the guy running the machine.
2) After the debacle that was the Shock Shootout thread, those who ran these tests have demanded total anonymity. Point blank: nobody wants their name associated with the pissing match that unfolded. So, everything here is offered under the condition the 'who ran them' remain totally anonymous. Again, if that doesn't sit well with you by all means stop reading this thread right now, and go do your own tests. Nothing here can't readily be reproduced in your lab with your equipment by your experts.
3) These tests are all specific to front shocks only! Do not use these results when trying to determine differences between companies or products for the rear. Why not test for the rear, too? We might. But for now, the general feeling from several sources is that the rears do not represent so dramatic of differences between the products, as do the fronts.
4) No winner or loser will be chosen here, nor will any conclusions be made about which shock is "best" based on these tests.
5) For now, this thread will be stickyed and left open for comment and discussion. Questions, comments? Please! Post'em up. Constructive discussion is encouraged, and I'll do my best to answer all questions. But... DO NOT TURN THIS INTO ANOTHER PISSING MATCH. If this blows up, ALL offending comments will be deleted (no editing, just mass deletion), the thread will be locked and another golden opportunity to interactively learn together will be lost.
Testing Generals
Finding a dyno to do these tests is no small thing, and even then finding one owned by a group willing to let you use it is an entirely different thing. Without getting crazy technical, most dynos are not large enough to handle the full range of travel and force levels these shocks can produce. The equipment used in these tests was custom built and specifically designed to help develop test and tune many of the best off road shocks the world has ever seen. Suffice it to say, this is one serious piece of kit.
In terms of the actual tests being carried out, extreme care was taken to ensure consistent conditions and procedures between tests and shocks.
Testing Specifics
-There were 3 main categories of tests run on each shock: (1) Hardware and Length Observations and Measurements, (2) Spring Rate and Ride Frequency, and (3) Velocity Cycle testing. The first two are conducted using precise measuring instruments and math to find various lengths at given positions as well as ratios and factors. The last one uses the dyno's abilities to apply force and velocity, and to measure the same throughout the cycle.
-The stock Fox, Fox 3.0, ICON 3.0, and King 3.0 Raptor shocks tested were all "brand new out of the box", and were of current production as of January 2013.
-All shocks where tested at ambient room temperatures (approx 72deg F). See post #57 for a discussion as to why.
Results
1) Hardware and Length Observations and Measurements
https://drive.google.com/open?id=1_oABL2n5gc34nG_yvAahTnqehFh11kcw
Details:
"Extended length" measures the overall length of the shock when extended as far as it will go. "Compressed length" measures the overall length of the shock when it has compressed as far as it will go. "Travel" is the subtraction of "Extended length" minus "Compressed length"; this tells us how far the shock can move from one end of its stroke to the other.
"Piston diameter" measures the diameter of the piston, "Shaft diameter" measures the diameter of the piston shaft, and "Hose size" is the AN size of the hose. "Port size" measures the diameter of the port between the shock body and the hose that connects to the reservoir.
"Upper" and "Lower pivot bolts" describe the size and type of hardware used to connect the shock to the truck, and "Compression Adjuster" and "Position Sensitive" are observations made about the shock's features.
Notes and comments:
1a) The King shock has the shortest compressed length; even shorter than stock. This means the King shock has the most "bump travel"; in other words, the King will travel further during its compression stroke, which means the tire is moving further up into the wheel well and may come into contact with the fender lining. On the other hand, the ICON has the longest compressed length, meaning the shock will travel almost one full inch less 'up' into the well, than will the Kings.
1b) The ICON and Fox 3.0 shocks effectively allow for the same (most) 'down' travel, which will result in the tire staying in contact with the ground longer than the other options.
1c) Unlike the other three options, the Kings are not position sensitive shocks, just velocity sensitive. This essentially means internally to the shock, the damping force is the same for a given velocity regardless of where the shock is in its stroke. The King has a user-settable external compression adjuster to restrict fluid flow into the reservoir. The ICONs are position sensitive and have an external compression adjuster.
2) Spring Rate and Ride Frequency Measurements
"Spring Rate" measures the amount of weight needed to compress a spring a certain distance. In this case, the following data is in terms of "how many pounds does it take to compress the spring one inch?" and is denoted as lb/in.
The Stock Fox springs compress at a rate of 525-550lb/in.
The Fox 3.0 springs compress at a rate of 550lb/in.
The ICON 3.0 springs compress at a rate of 675lb/in. 19% stiffer than stock
The King 3.0 springs compress at a rate of 600lb/in. 10% stiffer than stock
"Ride Frequency" is a calculated value used to help compare various aspects of suspension systems across vehicles. It's found by crunching spring rate, motion ratio, and corner weight through a mathematical black box (the details of which are beyond the scope of this discussion). The numbers of several vehicle types, as well as these shocks are offered here to help provide some perspective.
https://drive.google.com/open?id=11Z68rU1y63UUWSdhgmYS43y_Jp9EmM-2
Notes and comments:
2a) The lower the "spring rate" (the less weight it takes to compress the spring one inch), typically the better for off road applications since it indicates the spring will be more compliant, or forgiving. The less weight it takes to move the spring, the softer that rock in the road will feel. The term "better" here is very subjective, however, since we all have different ideas about what feels best to us.
2b) As you can see by the comparison, those cars that really need to corner like they're on rails will typically opt for a larger ride frequency, while those tasked with absorbing the biggest hits will opt for a system resulting in a lower ride frequency. You decide where you feel most comfortable on the scale.
3) Velocity Cycle Testing
WARNING: This is about to get real technical (relatively speaking).
The goal with this test was to compare how the "position sensitivity" of each shock behaves. In a nutshell, that means cycling the shock and measuring the forces as it makes its way back and forth through each zone. There are many ways to test this, but for our purposes and to keep things as simple as possible:
-a "square wave input" setting was used on the dyno
-the ICON and King shocks' compression damper adjusters were tested at both fully open and fully closed (and not in between). You can effectively infer what the graph would look like in between these extremes.
-the graphs are at 10" per second velocity to show the general shape, denoted as in/s.
-the ends of the curves have some fluctuation due to the acceleration and deceleration of the dyno itself
A note regarding how to read the graphs: The compression stroke is on the bottom and shown as negative numbers. Rebound is on top and shown as positive numbers. "Shock displacement" or stroke (travel) is in the X axis (inches) and force generated by the shock is on the Y axis (pounds)
Another note: the Fox 3.0s show a range of .75" more than the ICON and Kings. I'm hoping to update the graphs to show a consistent range soon.
https://drive.google.com/open?id=1VZB2qrGGv6LdfodZFeGvtP315dHlfG7C
The Fox 3.0 has 3 rebound zones, and 4 compression zones. On the rebound side, the shock generates less force at ride height and more force at both ends of travel. On the compression side the force increases in stages before hitting the final zone.
https://drive.google.com/open?id=1MgtU1h-hAueJvjyQrqHQK25cr9bD13UW
The ICON 3.0 has 3 rebound zones and 3 compression zones. The transition is effectively instantaneous as the secondary piston engages the bottom out cup. This allows for more bottom out control and "rebound stick" when compared to a mono-tube shock.
https://drive.google.com/open?id=11BFr_QlpmslelswXQIic4wPMOLU0qbzg
The King 3.0 is a mono-tube shock with no position sensitivity (1 rebound zone, and 1 compression zone). The forces are the same throughout the travel.
Here they are plotted to show rebound Force vs Velocity at ride height
https://drive.google.com/open?id=1kQqaeTjdVFcZLbxGehApFKEciNidRQSY
Here they are plotted to show compression Force vs Velocity at ride height
https://drive.google.com/open?id=1OsVQXMzeiawLXf3KgU89FPYiou1GnnIv
And here they are plotted to show compression Force vs Velocity within the bump zones
https://drive.google.com/open?id=1Az8_2UQnqF_w3PwZJW5eX8YSSSKHdW3J
Notes and comments:
3a) The theory goes, for off road applications, the more zones the better. The idea being each zone will allow for a step up/down of the force, and therefore allow for less dramatic transitions between travel extremes. The upshot of that approach is more control over the entire travel of the shock because the responses are more gradual. Although, there is clearly a point of diminishing returns; in other words, how many zones do our shocks/trucks really need given your driving style and goals? I leave it to the reader to decide for themselves how many zones is enough for them.
3b) Generally speaking, when tuning for off road vehicles, the rebound forces are kept low to allow for the wheels to "droop out" (move 'down') easier which in turn keep the tires in contact with the ground longer resulting in more traction. "Packing up" is also minimized when hitting multiple successive bumps when rebound forces are minimized.
3c) Generally speaking, when tuning for off road vehicles, the goal is to keep compression (damping) forces at ride height low, to allow the suspension to move freely 'up' with small bumps resulting in a "smoother" ride.
3d) Unlike when at ride height, when in the bump zone generally speaking the goal is to maximize the force to prevent bottom outs while still within the full travel of the shock.
***All the above is the data. The rest of this post is my interpretation of it.***
MyThoughts
The following are MY OPINIONS based on and WHAT I FOUND INTERESTING about all the same data you now have:
-I was surprised by what the data shows regarding one of the stated major advantages of the King 3.0; specifically its external compression adjuster. The numbers show that the adjuster accounts for a total difference in force of about 15%, and even less at slow shaft speeds (daily driving). I was expecting that feature to have a much larger effect.
-Unlike the King adjuster, the ICON adjuster makes a significant difference at ride height, at slow speeds. On the other hand, the adjuster seems to have a minimal effect when at the extremes of travel. If I owned a set of ICONs, based on the data I would fine tune my adjusters when on road, and then set them wide open when off.
-The king force levels are very stiff at ride height. They are 3x stiffer than stock. This will have a negative effect on small bump compliance.
-Both the Fox and Icon shocks have very effective bump zones and soft ride zones.
-I was surprised to see the high spring rates on King, and especially Icon shocks. On the other hand, it was interesting to see that Fox chose to use the same rate on their 3.0s as they do on the stockers.
Like I said right up front, I will not be picking a "winner". That aint the point. So then what is the point? Hopefully this can serve as a reference when considering differences between three of the most popular Raptor shock replacement options, as well as what to expect when upgrading to any from stock. I caution you however: these are notes, measurements, calculations and observations made in a sterile lab environment, miles away from any truck and any dirt. While it's appropriate to use the preceding as a reference, you have to keep in mind its only half of the picture, at best. The other half needs to happen 'out there', in the real world...
I hope you found this informative and interesting! Please feel free to comment and ask questions. But also please remember what I said about keeping this thread active, informative and open...
First, the ground rules
1) These results were not derived by me, nor were the tests supervised by me. They were, however, carried out by experts in the field who make their living on producing fair, unbiased, accurate and repeatable results. I will put my name and reputation behind these results as if I had carried out the tests myself. If that's not good enough for you, I encourage you to conduct your own experiments and produce your own results, and to close this thread now. Otherwise read the following with confidence as if I was the guy running the machine.
2) After the debacle that was the Shock Shootout thread, those who ran these tests have demanded total anonymity. Point blank: nobody wants their name associated with the pissing match that unfolded. So, everything here is offered under the condition the 'who ran them' remain totally anonymous. Again, if that doesn't sit well with you by all means stop reading this thread right now, and go do your own tests. Nothing here can't readily be reproduced in your lab with your equipment by your experts.
3) These tests are all specific to front shocks only! Do not use these results when trying to determine differences between companies or products for the rear. Why not test for the rear, too? We might. But for now, the general feeling from several sources is that the rears do not represent so dramatic of differences between the products, as do the fronts.
4) No winner or loser will be chosen here, nor will any conclusions be made about which shock is "best" based on these tests.
5) For now, this thread will be stickyed and left open for comment and discussion. Questions, comments? Please! Post'em up. Constructive discussion is encouraged, and I'll do my best to answer all questions. But... DO NOT TURN THIS INTO ANOTHER PISSING MATCH. If this blows up, ALL offending comments will be deleted (no editing, just mass deletion), the thread will be locked and another golden opportunity to interactively learn together will be lost.
Testing Generals
Finding a dyno to do these tests is no small thing, and even then finding one owned by a group willing to let you use it is an entirely different thing. Without getting crazy technical, most dynos are not large enough to handle the full range of travel and force levels these shocks can produce. The equipment used in these tests was custom built and specifically designed to help develop test and tune many of the best off road shocks the world has ever seen. Suffice it to say, this is one serious piece of kit.
In terms of the actual tests being carried out, extreme care was taken to ensure consistent conditions and procedures between tests and shocks.
Testing Specifics
-There were 3 main categories of tests run on each shock: (1) Hardware and Length Observations and Measurements, (2) Spring Rate and Ride Frequency, and (3) Velocity Cycle testing. The first two are conducted using precise measuring instruments and math to find various lengths at given positions as well as ratios and factors. The last one uses the dyno's abilities to apply force and velocity, and to measure the same throughout the cycle.
-The stock Fox, Fox 3.0, ICON 3.0, and King 3.0 Raptor shocks tested were all "brand new out of the box", and were of current production as of January 2013.
-All shocks where tested at ambient room temperatures (approx 72deg F). See post #57 for a discussion as to why.
Results
1) Hardware and Length Observations and Measurements
https://drive.google.com/open?id=1_oABL2n5gc34nG_yvAahTnqehFh11kcw
Details:
"Extended length" measures the overall length of the shock when extended as far as it will go. "Compressed length" measures the overall length of the shock when it has compressed as far as it will go. "Travel" is the subtraction of "Extended length" minus "Compressed length"; this tells us how far the shock can move from one end of its stroke to the other.
"Piston diameter" measures the diameter of the piston, "Shaft diameter" measures the diameter of the piston shaft, and "Hose size" is the AN size of the hose. "Port size" measures the diameter of the port between the shock body and the hose that connects to the reservoir.
"Upper" and "Lower pivot bolts" describe the size and type of hardware used to connect the shock to the truck, and "Compression Adjuster" and "Position Sensitive" are observations made about the shock's features.
Notes and comments:
1a) The King shock has the shortest compressed length; even shorter than stock. This means the King shock has the most "bump travel"; in other words, the King will travel further during its compression stroke, which means the tire is moving further up into the wheel well and may come into contact with the fender lining. On the other hand, the ICON has the longest compressed length, meaning the shock will travel almost one full inch less 'up' into the well, than will the Kings.
1b) The ICON and Fox 3.0 shocks effectively allow for the same (most) 'down' travel, which will result in the tire staying in contact with the ground longer than the other options.
1c) Unlike the other three options, the Kings are not position sensitive shocks, just velocity sensitive. This essentially means internally to the shock, the damping force is the same for a given velocity regardless of where the shock is in its stroke. The King has a user-settable external compression adjuster to restrict fluid flow into the reservoir. The ICONs are position sensitive and have an external compression adjuster.
2) Spring Rate and Ride Frequency Measurements
"Spring Rate" measures the amount of weight needed to compress a spring a certain distance. In this case, the following data is in terms of "how many pounds does it take to compress the spring one inch?" and is denoted as lb/in.
The Stock Fox springs compress at a rate of 525-550lb/in.
The Fox 3.0 springs compress at a rate of 550lb/in.
The ICON 3.0 springs compress at a rate of 675lb/in. 19% stiffer than stock
The King 3.0 springs compress at a rate of 600lb/in. 10% stiffer than stock
"Ride Frequency" is a calculated value used to help compare various aspects of suspension systems across vehicles. It's found by crunching spring rate, motion ratio, and corner weight through a mathematical black box (the details of which are beyond the scope of this discussion). The numbers of several vehicle types, as well as these shocks are offered here to help provide some perspective.
https://drive.google.com/open?id=11Z68rU1y63UUWSdhgmYS43y_Jp9EmM-2
Notes and comments:
2a) The lower the "spring rate" (the less weight it takes to compress the spring one inch), typically the better for off road applications since it indicates the spring will be more compliant, or forgiving. The less weight it takes to move the spring, the softer that rock in the road will feel. The term "better" here is very subjective, however, since we all have different ideas about what feels best to us.
2b) As you can see by the comparison, those cars that really need to corner like they're on rails will typically opt for a larger ride frequency, while those tasked with absorbing the biggest hits will opt for a system resulting in a lower ride frequency. You decide where you feel most comfortable on the scale.
3) Velocity Cycle Testing
WARNING: This is about to get real technical (relatively speaking).
The goal with this test was to compare how the "position sensitivity" of each shock behaves. In a nutshell, that means cycling the shock and measuring the forces as it makes its way back and forth through each zone. There are many ways to test this, but for our purposes and to keep things as simple as possible:
-a "square wave input" setting was used on the dyno
-the ICON and King shocks' compression damper adjusters were tested at both fully open and fully closed (and not in between). You can effectively infer what the graph would look like in between these extremes.
-the graphs are at 10" per second velocity to show the general shape, denoted as in/s.
-the ends of the curves have some fluctuation due to the acceleration and deceleration of the dyno itself
A note regarding how to read the graphs: The compression stroke is on the bottom and shown as negative numbers. Rebound is on top and shown as positive numbers. "Shock displacement" or stroke (travel) is in the X axis (inches) and force generated by the shock is on the Y axis (pounds)
Another note: the Fox 3.0s show a range of .75" more than the ICON and Kings. I'm hoping to update the graphs to show a consistent range soon.
https://drive.google.com/open?id=1VZB2qrGGv6LdfodZFeGvtP315dHlfG7C
The Fox 3.0 has 3 rebound zones, and 4 compression zones. On the rebound side, the shock generates less force at ride height and more force at both ends of travel. On the compression side the force increases in stages before hitting the final zone.
https://drive.google.com/open?id=1MgtU1h-hAueJvjyQrqHQK25cr9bD13UW
The ICON 3.0 has 3 rebound zones and 3 compression zones. The transition is effectively instantaneous as the secondary piston engages the bottom out cup. This allows for more bottom out control and "rebound stick" when compared to a mono-tube shock.
https://drive.google.com/open?id=11BFr_QlpmslelswXQIic4wPMOLU0qbzg
The King 3.0 is a mono-tube shock with no position sensitivity (1 rebound zone, and 1 compression zone). The forces are the same throughout the travel.
Here they are plotted to show rebound Force vs Velocity at ride height
https://drive.google.com/open?id=1kQqaeTjdVFcZLbxGehApFKEciNidRQSY
Here they are plotted to show compression Force vs Velocity at ride height
https://drive.google.com/open?id=1OsVQXMzeiawLXf3KgU89FPYiou1GnnIv
And here they are plotted to show compression Force vs Velocity within the bump zones
https://drive.google.com/open?id=1Az8_2UQnqF_w3PwZJW5eX8YSSSKHdW3J
Notes and comments:
3a) The theory goes, for off road applications, the more zones the better. The idea being each zone will allow for a step up/down of the force, and therefore allow for less dramatic transitions between travel extremes. The upshot of that approach is more control over the entire travel of the shock because the responses are more gradual. Although, there is clearly a point of diminishing returns; in other words, how many zones do our shocks/trucks really need given your driving style and goals? I leave it to the reader to decide for themselves how many zones is enough for them.
3b) Generally speaking, when tuning for off road vehicles, the rebound forces are kept low to allow for the wheels to "droop out" (move 'down') easier which in turn keep the tires in contact with the ground longer resulting in more traction. "Packing up" is also minimized when hitting multiple successive bumps when rebound forces are minimized.
3c) Generally speaking, when tuning for off road vehicles, the goal is to keep compression (damping) forces at ride height low, to allow the suspension to move freely 'up' with small bumps resulting in a "smoother" ride.
3d) Unlike when at ride height, when in the bump zone generally speaking the goal is to maximize the force to prevent bottom outs while still within the full travel of the shock.
***All the above is the data. The rest of this post is my interpretation of it.***
MyThoughts
The following are MY OPINIONS based on and WHAT I FOUND INTERESTING about all the same data you now have:
-I was surprised by what the data shows regarding one of the stated major advantages of the King 3.0; specifically its external compression adjuster. The numbers show that the adjuster accounts for a total difference in force of about 15%, and even less at slow shaft speeds (daily driving). I was expecting that feature to have a much larger effect.
-Unlike the King adjuster, the ICON adjuster makes a significant difference at ride height, at slow speeds. On the other hand, the adjuster seems to have a minimal effect when at the extremes of travel. If I owned a set of ICONs, based on the data I would fine tune my adjusters when on road, and then set them wide open when off.
-The king force levels are very stiff at ride height. They are 3x stiffer than stock. This will have a negative effect on small bump compliance.
-Both the Fox and Icon shocks have very effective bump zones and soft ride zones.
-I was surprised to see the high spring rates on King, and especially Icon shocks. On the other hand, it was interesting to see that Fox chose to use the same rate on their 3.0s as they do on the stockers.
Like I said right up front, I will not be picking a "winner". That aint the point. So then what is the point? Hopefully this can serve as a reference when considering differences between three of the most popular Raptor shock replacement options, as well as what to expect when upgrading to any from stock. I caution you however: these are notes, measurements, calculations and observations made in a sterile lab environment, miles away from any truck and any dirt. While it's appropriate to use the preceding as a reference, you have to keep in mind its only half of the picture, at best. The other half needs to happen 'out there', in the real world...
I hope you found this informative and interesting! Please feel free to comment and ask questions. But also please remember what I said about keeping this thread active, informative and open...
Last edited:
at least not what I expected but it makes me happy to see the stock shock performance.
