Now that I have a good triple rate spring set (dual rate with helper) up in the rear. It’s time to work on the front shock, going with a zero preload set up to match the rear. This set up will be a helper spring with an 11lb/in rate and a single linier rate spring. The goal here is to match the set up of the rear as not to upset the handling due to the effected change on the front of the machine. I have also mentioned a change in valving, driver ride height, and sag %. It seems I am all over the place with things however it was a plan to change the machine from a dune chaser to an all around area machine with doing static changes in ride height, sag% and adjustments in low, high speed compression and rebound. Basically a turn here and there and good to go without changing: Springs, Caster, Camber and Toe. The lovely wife just shacks her head at me and says you just have to mess with it don’t you. Guess I am never satisfied with the how it performs area to area plus I like to wrench on my Pilot when I can. Just like a Quad or UTV this can impact the handling of the machine.
Since I tend to bla bla bla I took a different approach with modifications to the machine. In each post I place a picture or two and a statement or two leading further to the goal. So reading or skimming thru each leads to another etc. In this case it was the pictures I took and posted on how the pilot looks sitting from the side. Other picture to look over was the shocks and the springs at different setting and compare to the side view.
This leads us to why change the front spring and valving set up to go with the rear other than I used a helper in the rear. The front had a dual rate set up which had a Tender Spring, Main Spring and Cross-Over Spacers. Different from the rear which had a dual rate set up with cross over collars. The difference is the rear can be fine tuned by turning the collars up and down for a given cross over point and the front has to use different length spacers in between the Tender Spring which requires the Spring Stack to be removed from the shock and spacers changed. This was a mistake when I ordered them for Penske years back so that’s my Bad. When new shocks are ordered they will have this ability to fine tune. It’s not more money, so URRRRR. For this set up it’s not good in way of adjustability for different sag %. As I raise and lower the ride height via Static Pre-Load it changes the cross over point on the shock at a different shaft length changing the shocks applied load. So you see it’s not as easy to change the static setting for different areas without upsetting the machines handling.
This leads us to the subject at hand and the way the machine sprung weight sets front to rear or there ride heights. I call this the Chassis Ride Height or Attitude. We see this a lot on our modified suspension for our machines and Bull like to comment on it every time “the front looks a little high”. So what is He talking about and what does it affect. We can imagine a horizontal line just a flat line across the page with no angle to it. In my 250R days we called it a flat liner, so we knew it was most likely not set up right and would handle poorly. Still true today with 450’s and UTV’s and or Rides. Now you see the relationship to for mentioned pictures and the way it set from the side. In the old days (1988 TRX 250R and 1989 FL400 Pilot) we could not make as many adjustments to front end in way of Caster, Camber to offset some of these negative effects. They did make different arms one just could not afford them or I could not. So fixing a flat line was done with sag only front to rear or changing that flat line to a straight line with an angle to it and re-valving the front shock on the 250R and nothing on the FL400. I now Bla Bla BLa, This is why the static preload is so important and one of the first things to do to achieve a desired Attitude of the machine. You can also see why the work shock was a vast improvement over stock on the fl400 and front trx250r. They’re not going to tell you that and why it improved its overall handling. Don’t take my word for just look at FL 400’s that have stock and works you will see a difference. Keep in mind the factory setting on geometry has not changed and is set. This is why 250r and 450r front spindles do not work well on a stock machine; it’s all out of wack. Now you have the base line facts and an idea of the Bla Bla Bla. We can move forward to the change of the front spring set up.
The front Helper spring is an Eibach HELPER200 its Length: 2.83”, ID: 2”, Rate: 11 lb/inch, Block Height: .43”, Travel, 2.40, Weight: Who cares. This spring will set atop an 8” tall linier rate 240 lb/inch spring with a zero pre load and cross over at Block height. Then I can add static preload to set the front at a desired ride height for a given Attitude for a desired sag% without changing the Camber, Caster and Toe. At 11 lb rate the blocked out poundage will not upset my valving too much based on a single rate. As I add static preload to the block height at 240 lb /inch it will not take much to raise it where I need it and maintain a fixed rate. The added static load will affect the rebound portion (get quicker) so a click or three will fix that. What also need to be taken into account is the leverage ratio of the shock and its placement on the arm. Leverage ratio would be shaft movement in inches compared to wheel movement in inches. Example would be shaft 5” wheel 10” it would be a 2 to 1 ratio. If you look at that example now the spring rate of 240 does not look so harsh or 120 per inch of wheel travel. The real world number will vary with my set up is couple different ways. I have two (2) shock positions on my arms which affect three items, Motion Ratio, Shock Angle and wheel rate. Motion ratio was covered already so let’s look at the Angle of the shock and multiplier that would apply. This not a big deal if by moving the shock angle with a few degrees from what you have. If more than 1 or 2 degree you should factor it in. Simple to do in way of COS (cosine) of angle, open up your calculator on your phone enter shock angle in degrees 10 than hit COS button=.984. In my case I am taking the shock from 30 degrees to 25 degrees or .866 to .906 % efficient. This relates to the rate in a way of an increase in rate of 207 to 217.44 or 10.44 lb inches. Now with a rate on the helper of 11 x 2.4(travel) 26.4-10.44=15.96 lbs of change. That was the easy part, the third thing is the placement of the shock on the arm I moved it in which not only changes the motion ration but the wheels rate or the rate the wheel sees. There’s is a little more involved and may loose ya unless you want to hear about it. So I will skip past however take note as I will use it in another post.
Back to Motion ratio, and the impact of the shaft and poundage. At 4-3/4 (4.75) inch shaft and a wheel travel of 12.5 (12” effective) 12/4.75=2.526 which is kind of high I like to stay within 2 to 2.5. The effective spring rate now at 217.44 and a motion ratio of 2.56 were at 96.38 of rate per inch of wheel travel not including the effect of the wheel rate its self. The initial 240 lb/in spring does not look so bad compared to the 96 lb/in calculated. With this I can compare to rear final rate which I will cover later. I can now take the Helper travel of 2.4 and subtract it from the shaft of 4.75 and get a bottom out poundage. I’ll take the shaft length of 4.75-2.4(helper travel) =2.35 inches of shaft times 2.526 (motion ratio) 2.35 x 2.526= 6 inches of wheel travel at zero preload. Darn near 50% which is where the rear is at right now. This allows for adding static pre load for ride height adjustments. If I look at the dual rate number and sag it provides I can easily compute what preload I need and or Block height for the 240 spring to get the correct attitude. For a bottom out poundage for this I would simple take the spring rate of 240 x 2.35=564 not including the bottom out bumper. For this package I would use a progressive rate and add 1100 pound at final by replacing the tall soft bumper with a short stiffer one.
Head hurt yet? Good thing I did not add the wheel rate into it.
As you can see this would require more compression damping and a more aggressive rebound damping. Since I use a single rate on the front valve stack and a high flow linier piston in the shock it’s an easy fix. For compression I go from .050/.007 (thickness) to a straight .008 with rate plate and for rebound I go from a straight .008 to a .010/.015, I also used a 5 wt at 220. PSI this allows me to control from the adjusters. You may ask why so aggressive on rebound. It is due to the motion ratio of the shock to control the leverage ratio of the arm. The force acting on the arm at the wheel will be higher so I need to add damping. This will help keep the attitude in check when hitting the rough sections and dial in the chassis lift from the rear with the adjusters and the changed valving. Yep back to the line thing and its angle. Now you can see the big picture of the testing I did last couple of months it was not all about the clutches. No I am not done yet, you wish, Fat chance!
We should look at the impact on other items due to this change good bad whatever. So when it comes to sag and the attitude we want an attitude that is good for the machines settings, duuuu. First look at what was done. Increased sag; lowered the ride height front to rear which yield a lower center of gravity. I say that is a good thing for corner stability etc. It also allows for the body roll to take set quicker. It allows for more down travel on inside wheels while cornering as not to have great impact on wheel load and straight line surface irregularities or big hole and keep attitude in check not pulling chassis down. Less low speed valving (adjusters) required so ride is not harsh at low vehicle speeds. Most that have a long travel have some sort of bump kit for their steering set up. With a lot of them the steering it harsh or stiff and use a power steering. I have found with a lower ride height the steering tie rod angle is much less and so much easier to turn darn near as good as stock. The down side is a little feedback just like stock I would say there is a trade off there. What I did was take this into account for new Caster Camber and Toe setting along with the attitude setting. Starting in the front I found a good happy medium in the steering and set front ride height. Then I set the attitude from the rear remember the fine tunable cross over and ride height adjusters. Then set camber, then caster then toe. Keep in mind I’m using a 05 TRX 450r front set up. The Camber is ¼” negative, Caster is set at 3 degrees positive, Toe is set at ¼ in. I will not even bring Ackerman into it as you will go “I’m out of here” which I have some adjustment built into the bolt on bump kit. For me I this works well for my Pilot. The rear valving took on new numbers as well. I soften up both compression and rebound as these shock come to stiff from AXIS. The rear adjuster has a ton of room in them. The rebound was just too stiff and was packing and pushing the chassis (kicking) up to much thru the woops. I used a high flow linear 1 degree dish valve (preload on compression) with a .005/.007 straight linier with rate plate for compression. I used a flutter stack .005/.008 - .010/.015 (dual rate) progressive on rebound. This will allow for high rebound shaft speed at low compression shaft speeds and slower rebound shaft speed at high compression shaft speed. With Penske they use a letter system for valving like A, A+ and A-, A is a linier set of one thickness (4- .006). An A- set is two of one (A’s .006) and the next two one smaller (2-.006, 2-.004). An A+ set is is two A’s and the next two larger (2-.006, 2-.008). Then they use a Letter over a Letter for the valving, the first letter being Compression and second Rebound, kind of confusing until you get use to it and wrap your head around it. Fox is much easier. So my new front setting is a B .008 over C .010/E .015. For rebound I could have used a C+ and been close. I left OD out of it to save you the additional pain. Talk about pulling your hair out. TMI?????

Goes to show it’s all about attitude!

First one to the medicine cabinet wins a prize, Prize yet to be determined.

You lost me right at the part where you said: "It’s time to work on the front shock,"
CO

You think I’m gonna read all that you are mistaken. That’s a F’in novel.

Ok
Short version, got front springs.
Lowered the machine and leveled it out some.
Played with the shock valving.
Hope it works
If that don't work I'm coming to post a picture.
Plus I had nothing else to do today.

That's the same philosophy I got.
CO

On my fl617 350 sand monster I ended up using the 350 stock rear springs for the front setup which is running snowmobile shocks and Farr long travel. The suspension angles and leverage required that much spring rate up there. Single rate. That said I don’t mind the single rate setup on my Fl600 Dave-Co long travel Pilot either.

My fl400 has works shocks. I like them. This machine is my middle best.

Time for some attitude
This time I will discuss attitude adjustment, No not a CO party favor. I will try to do better than the rambling I had done previous. This time with pictures for those that can picture read, like me. With the back ground information it’s time to move onto what I left out on purpose which is the RAKE of the front arms. I will start will the bull comment again, “Front looks high”. The higher the front set in the air compared to the rear increases the Rake angle of the front lower and front upper control arms. With a modified 350 that has arms put on it hopefully this was considered prior to setting the ATTITUDE. Most use some type of factory arm set up adapted to the machine. I would recommend as a starting point look at the factory or aftermarket recommendations for this compared to the rake of the ATV. Now for the pilot that is an easy one since we’re adding arms to it and the rake is already established. Using stock hub assembly’s on aftermarket arms can be quite challenging if this is not taken into account. One of the first thing we notice when using aftermarket arms and shocks is the front goes up unless someone made them to be stock replacement with a few changes. Most leave the rear alone or use a works shock or an old Fox. I will use mine as an example 2005 TRX 450r +2+1 fully adjustable with the exception of the lower arm. I was lucky to have a 450R to use as a guide for this so it took a lot of guess work out of it.
Since the rake needs to be taken into account what happens if we do not and the Attitude is way off. The increase in rake angle on the front makes the arms static setting hard to dial in from what in what we consider normal settings. Then as we hit the rough stuff we have to change their settings or not. However it doesn’t turn worth a heck of beans and handle like poo. So a trade off is made or you change the setting to gain a happy medium. So the rake angle plays a part in the front wheel load and most important excessive rake angle cause UNDERSTEER. Starting to make since for what we read and see on the board. Since I changed my set up and added rear sag the front had to change to keep the angle in check with minor static setting proving me with a range of rider sag (30 to 50%) without upsetting the rake angle. A change in the valving also had to correspond with the new sag and spring rates to work in unison as not to upset the load transfer front to rear for CG (center of Gravity). This is where the pictures will show what I just rambled about.
You will noticed a different appearance to the machine almost stock ride height (AKA sleeper), the rake angle mentioned and what I call float height as to maintain this rake angle as not to upset the static settings in a dynamic way. This way I start off true on the static setting then make shock setting changes and not chase my tail. In the pictures it will show that I do need to make one adjustment to the caster due to this rake angle dynamic change in the rear float position. I will need to add 1 to 1.5 degrees of caster to what I already have or add preload changing to attitude. The goal is to keep this rake angle static within 10 to 15 degrees. If cannot be done with preload a spring change will be made to achieve this to keep the tire loading and roll angle in check. You may be going the dude has finally lost it.

Now why the static change in caster and or preload? As the rear floats it decreases the rake angle on the front which in turn reduces the caster angle. The front in under a new heavier load and can past zero caster and we all know negative caster is a no no and it with swap side to side and get sketchy. In the first series of pictures you will see I have the new setup rake angle set at 12.5 to 13 degrees. You will also see the attitude of the machine at a much lower ride height and the tie rod angle mentioned in the other babble novel.

The second series of pictures will show the rear static and front lifted to a rake angle of 15 degrees and the attitude of the machine as well as the change in tie rod and a-arm angles.

The third series will show the front back to static and the rear lifted to a 10 degree rake angle and the attitude of the machine.

The fourth series will show a balance point lift of the machine to a full droop on all four corners from ride height and a number which represents chassis lift/wheel droop times 2 for float height based on 45% free sag. The rider sag will take it closer to 50%. The chassis lift or wheel droop is 5.375 times 2 =10.75 (10-3/4) inches at float from balance point. So the float height is where you lift one wheel up to that number it should leave the other three on the ground and measure your roll angle. I know kinda weird however I’m kinda weird. Then I take this number and compare it to the wheel travel numbers front to back. The average should be within ½” or so. This tells me which to go with the spring rates front to rear. Now I feel confident I can hit the hard stuff fast without tipping over the machine and let it walk through. The next two series will show I’m close to what I projected.

The fifth series is the front float height. The number is right around 10-½ so real close and you can see the role angle is not bad at that attitude.

The sixth series is a little more fun because we factor in Rake angle for front caster dynamic change because of wheel load. You can see that the roll angle is good and the attitude is good or real close. The float number is a touch off at around 10 to 10-1/4 inches. For a static test I can live with it. Most important is the rake angle which is at 6-1/2 to 7 degrees. So a static change in attitude (rake angle) will fix the float number and a static change in the caster will fix the rake angle change by going from 3 to 4.5 maybe even 5 if the under steer is in check. If I did the float test with driver I would probably be even closer.
Based on this I can now use this base line and simple make preload adjustment and change the ride height and clicker for different riding area. This was the goal after all. For fun go do this to you stock pilot and see how it compares. See what the stock rake angle and attitude is with the stock caster. If you have works shocks compare that to the stock shocks. UMMMMMM.

To sum it up, as always I am no professional in any way just a back yard hacker.

Short version

Built me up a set of triple rate spring to try out as well. Zero preload with dual rate to match the rear. Helper, Tender and Main

Now all I need is some warm weather to go play. I did hear it snowed at LS in oklahoma.
Ummmm go bust some caps?

Spent the day doing some fine tuning o the Triple Rate Spring set up. When I was done used the raddle can on the spring and did some bump and jump testing to get a base line adjuster settings. This will make it easy to dial in at the test area. Low speed compression 10 clicks from full open, High speed compression 9 clicks from full open, Rebound 15 clicks from full open. This leaves me a lot of room for adjustment.
No babble so enjoy the pics.

more pics

A final attitude check and done with this set up.

Meticulous! And a sweet machine. Very Nice.

Thank you,
John, I am following your build.