General Suspension Theory

[fast_man58]

well earlier this afternoon i put together a list of differnt shock companies and a brief description and a picture of both. i just threw it together in a quick 10 minutes and it didnt look all to swell. so iv been doing some thinking and im going to put together a list of manufactures and combos (arms/shocks) that are a good setup.

hopfully i can clear up some questions and will let some people know about how things work. ill give pictures of each brand and the differnt models each company offers. i will also go into detail on adjustments, features, price, customer service, turnaround time, and overall appeal/quality of each shock.

to get started, we must know about the adjustments/features on the shock.
PRE LOAD- this is the spring tension adjustment. it controlls the overall stiffness of shock
RESIVOURS- cylindrical "storage tanks" that are partially filled with oil, and partially filled with compressed nitrogen gas with a diaphram seperating the two. ads extra oil capacity for more controll and less fading of the shock.
COMPRESSION- this adjustment is located somwhere between the body and rezzie of the shock. its basically a glorified needle valve that controlls the amount and the speed of the fluid that is going out to the rezzie. Some Elka shocks offer High and Low speed compression adjustments. these will controll the shocks SHAFT speed. the high controlls the high speed impacts while the low speed controlls the slower less noticable bumps. this adjustment is probably the most needed as far as fine tuning your shocks.
REBOUND- this adjustment controlls how fast/slow the shock shaft returns to its extended position.
CROSSOVERS- these are small "ring" like spacers between different springs. these will only be found on multirate shocks. they controll the progression of the shock.
SPRING RATES- some shocks feature multiple springs. this is called a multirate shock. the theory behind this is that the upper springs are softer and will take the impact of smaller bumps, while the main spring will take the beating of the large jumps and hard landings. again, this is adjusted using differnt crossovers.

Progressive[/i]
Adjustments- preload, compression (H/L), rebound
Features- new "6th-sence" valving technology, Control Valve Technology, position sensitive damping control. very advanced technology. Five controls independently adjust bottom out resistance, low speed compression, high speed compression, rebound, and preload.
Price- $, havent seen a price yet, but im sure its not going to be cheap!
Customer Service- because these shocks are soo adjustable, they dont need to be revalved. thus, almost eliminating Customer Service. but PS has been around for a good number of years and would help you out in geting a great set of shocks
Turnaround- since they have no specific valving (at least to my knowledge) they could simply be shipped directly to you.
Appeal- perhaps the best looking out of our line up. large piggyback rezzies which get their fluid from dual compression adjustments look trick. deffinently should not pass these up on your search for a better suspension!


as you can tell, ading a set of good aftermarket shocks to your machine will greatly enhance the ride quality. its a night and day difference compared to the stock units. but, theres more to it then just shocks alone.

next we will take a look at a-arms.

as far as the design of the arms is concerend, there are only two. standard and long travel. the standard uses a stock lengh shock, and the long travel uses a slightly longer one. the only real difference between the two (becides looks) is the ease of tuneablity of the long travel. because it uses a longer shock, you can notice the shock settings better. concequently, when you make an adjstment on your shock (ex. increase the compression) you will notice it slightly more they you would on a standard travel arm. the long travel arms also offer a slightly better ride quality. close to the same can be acheived with standard arms, but will take alot more skill to adjust and more fine tuning.

in the world of long travel, there are straight arm designs, and gull wing designs. the straight arm design will have the shock mount under the main tube on the lower, where as the gull-wing design droops down allowing the shock mount to stay on top of the arm. there is no real advantage to the gull wing design, as the shock mount point will be in the relative same location as the straight arm. the key to making a suspension work properly is the leverage ratio. the same leverage ratio can be achieved using either style.

heres some info i wrote up along time ago:

lets set up 3 points. we'll call the frame mount point A, the shock mount point B, and the spindle mount point C. the first arm is a basic gull-wing design. the second is a straight arm (Laegers,JB), and the last would be the "loops". i have drawn with the best of my abilities in Paint a light blue line representing a shock. the shock is the same length in all 3 cases. now also note that the mounting points are the exact same in all 3 cases. so if the points are the same and the ball joint position is the same...then what makes a gull-wing design any better?

"there is a point behind it and its usually to run a longer shock which increases travel."
the straight arm can run just as long of a shock as a gullwing arm. notice the mounting of the shock remains undernieth the arm. thus...giving room for a longer shock. however, laegers feels that a shorter shock runs better, but houser on the other hand uses a 18.5" shock on a straight arm design. all they did is change point B down farther on the tube.

"the gullwing is designed to help lower the ride height " in the drawing above, you will see a very fine yellow line running through the red arm. it represents a straight tube design. and also note taht the mounting hole is below the yellow line allowing you to run a longer shock as i stated before. now with point A and C being in the exact same place, how could you get a lower ride height? but maybe my drawings are not representative of what a gibson a-arm really looks like, and maybe their bends do alow for a lower ride height.

i just dont see a real advantage on the gibson arm from a design standpoint. the only way you could tell which one you like best would be to ride both setups and see which one handles better for you. either way, you wont go wrong. both are made to high standards with high quality parts!

the quotes i put in there were objections that another member made in regards to the gull-wing design.

again, i will put together a list of terms that you should know when dealing with A-arms. (these definitions can be long, but are critical to set up any good suspension)
LEVERAGE RATIO- this is a ratio of wheel movment to shock shaft travel. the ideal ratio is 2:1. this allows the best ride quality and the most tuneability. i believe that this is measured from ball-joint or hiem joint on the end of the arm.
SHOCK MOUNT- the shock mount is simply the position of the arm that the bottom bolt of the shock mounts up to. it should be well tied into the arm so the load can be distrubuted evenly, not just some tabs welded to the tube .
WIDTH- as you can imagine, this is how wide the arms will make your quad. they come in +1 +2 +3, and all sizes inbetween. many people are confused by how wide they will really make your quad. simply put, the "+2" label given to the arms means that it will add 2 inches PER SIDE, not over all.
BUMPSTEER- bumpsteer is the tendency of the wheels to toe-in when the arms go through their travel. it is most commonly found when landing hard (making the arms use up all the shock travel) or when the front end is off the ground (having the shocks fully extended). this can be fixed by seting up your front end properly.
CAMBER- Camber is the angle of the wheel relative to vertical, as viewed from the front or the rear of the car. If the wheel leans in towards the chassis, it has negative camber; if it leans away from the bike, it has positive camber. The cornering force that a tire can develop is highly dependent on its angle relative to the track surface, and so wheel camber has a major effect on the track holding of a quad. It's interesting to note that a tire develops its maximum cornering force at a small negative camber angle, typically around neg. 1/2 degree.
CASTER- Caster is the angle to which the steering pivot axis is tilted forward or rearward from vertical, as viewed from the side. If the pivot axis is tilted backward (that is, the top pivot is positioned farther rearward than the bottom pivot), then the caster is positive; if it's tilted forward, then the caster is negative. a slight positve caster is wanted, and comes from the factory like so.
<span style="color:blue">TOE- This is simply the condition of the wheels relative to each other. when a pair of wheels is set so that their leading edges are pointed slightly towards each other, the wheel pair is said to have toe-in. if the leading edges point away from each other, the pair is said to have toe-out. the amount of toe can be expressed in degrees as the angle to which the wheels are out of parallel. toe in is always wanted, and toe out is never a good thing . your quad will basically handle like poo.

because there are so many brands of A-arms out there, i will leave that decision up to you. there are soo many of them to choose from, it can be confusing and hard to find the right one. keep in mind that just because an arm uses a longer shock, dosent mean it will ride better or have more travel. you should try and stick with a 2:1 leverage ratio arm (when dealing with long travel). i personaly dont care for Heim Joints on the lower arm. the spherical ones in arms like Walsh and RPM seem to be designed correctly, but the exposed ones found in arms like Fireball (Janseen, Denton, and SandDragon arms) dont really appeal to me. they claim a greater strength, but the 22,000 puond force rating isnt in the vertical direction, but rather the horizontal direction. AKA the pulling force. heres a crude drawing to give you a better understanding.

again, this is my personal perfrence. keep in mind that the Heim Joints are much more susceptable to dirt, water, and grime getting inside them because they offer no protection as oposed to Ball Joint boots. this causes extreem premature wear and tends to make them fail faster then a quality ball joint.

with this being said, im finished with my small tutorial on suspension. it is clear that aftermarket shocks; no mater if their top of the line Axis, or basic Ohlins will drasticly enhance your machines ride quality. this leads to easier riding which in turn leads to faster lap times at the track, or a better, more enjoyabe day at the dunes .

i think that it would be a good idea if members with aftermarket suspension were to make a brief post about their setup . it could include a picture, their thoughts, and some of the Pros/Cons about it. this way other members could read through and see which set up sounds the most appealing to them.

*prices and availibity are subject to change with out notice*


BUT WAIT, THERES MORE

as per the request of some members on this site, i will be giving some tips on setting up the suspension. (and they're free! )

well lets get started shall we? we're going to be looking at the setup principals as noted above (caster, toe, etc..) the first thing to look at will be seting the proper ride height. for MX, your going to want the back frame rail where the pegs mount up to be 7" off the ground. then, take a measure 5" towards the front of the bike on the lower main rail. this reading should be 7 1/4" meaning for every 5 inches you move up towards the front of the bike, it should raise 1/4". and dont forget, these and all other measurements/adjustments must be done while seated on the quad. this is a 2 person job, so grab a friend or your dog. wait, scratch the dog, intense training would be required . for other types of riding, such as XC or dunes, i slightly higher clearance is needed. and tire size plays a major part in this too . for MX a 20" front should be used, and a 18" rear.

once you have that set up, you can begin to adjust your other features. ill leave that one up to you. adjustment styles are different on different styles of arms. but ill give you some measurements for a baseline.
Camber- MX 2.5-3 degrees negative camber(top of the tire leaning toward the center of the quad). Trail riding and desert, negative 2 degrees.
Caster- MX 5.5-6 degrees positive, trail riding and desert 6-6.5 degrees positive.
Toe- in an 1/8-1/4 inch.

to simplify caster (and not many arms have caster adjustment), the top ball joint/heim should be 5/8" set back from the lower one. this would be from a top down view. again, this is just a baseline reading, and should be fine tuned.

compression and rebound settings are completly up to you. different riding styles and condtions make it extreemly difficult to pin-point which setting will work best without being there. but for a general statment, MX riders will want a rather stiff compression setting, and a some-what fast rebound. XC racers will need soft compression adjustments to soak up all the bumps, and a medium to quick rebound. desert....well, im not gonna lie to you, i have NO CLUE? but i could only assume somewhat soft for compression. if your into TT or ice racing, then you will need stiff compression, and slower rebound. and ovcourse being low is another must.

[bigjosh37]

Nice compalation.

[snox31]

nice work, you must have alot of time or you are just that good with a computer,that would take me so long the shocks would be out dated by the time i was done

[alba450]

Thanks for putting your time in on this. I know plenty of people that are clueless as I was. Now I know where to send them without being biased.

[fast_man58]

Originally posted by snox31@Nov 16 2005, 09:09 PM
nice work, you must have alot of time or you are just that good with a computer,that would take me so long the shocks would be out dated by the time i was done

[snapback]325762[/snapback]

haha well i have a little of both. i can move right around on the computer, but i didnt have skool today now i just gotta get my collection of a-arms and do some "reviews" on thoes.

[walshyfz86]

nice write up I think those 6th sence shocks are 1600

[pigeon-13]

That was a great review. I talked to fox reps. and the fox evols are in the ball park of 1300.00

[domin8]

Nice post FM. meow. Good work.

[xxx]

Good work, it's allready help me out

[YFZ450 Blaster Racer]

U forgot Ishock, i'm still waiting too see how they handle on a yfz.

[Terse]

Good job This should be pinned. This write up would definatly help others who are looking at all the choices and who may have questions about them.

[fast_man58]

sory about the iShock mixup. iv never heard of anybody using them yet, or their customer satisfaction ratings. so i figured id leave them out insead of providing phony info about them.

i believe this will be getting pinned, that is, once E3 gets back

[Earnhard3]

Originally posted by fast_man58@Nov 19 2005, 05:39 PM
i believe this will be getting pinned,* that is, once E3 gets back

[snapback]326924[/snapback]

I'm back sad to say however consider it pinned VERY good INFORMATION

[Duane]

Originally posted by Earnhard3@Nov 20 2005, 07:31 PM
I'm back sad to say however consider it pinned VERY good INFORMATION

[snapback]327281[/snapback]

Welcome back Scott.....welcome back to hell.

Glad you pinned this though...very good info.

[UpOnTwo]

that has to be the longest post ever! just kidding. that was great info. really informative and nonbiased. I will use this to my advantage more than once or twice. I think I speak for everyone here when I say THANK YOU

[fmxer4life]

WOW! thats awsome i will use that alot..i knew some things about suspention and that filled in the gaps thank you very much cant wait to see the a-arms

[fast_man58]

Updated "tips for setup" for thoes who wanted it

[sschmi5519]

Thanks for the "updatation."

[yfzracer86]

first id like to say you have came up with some DAMN good information and from reading your post i have def. learned a few things i did not know myself. I also saw some false information that i would like to clear up.

"for MX, your going to want the back frame rail where the pegs mount up to be 7" off the ground. then, take a measure 5" towards the front of the bike on the lower main rail. this reading should be 7 1/4" meaning for every 5 inches you move up towards the front of the bike, it should raise 1/4".

No, this is totally untrue. There are many variables when it comes to setting up your ride hight. There is no, and will never be a standard Setting for anything on suspention, but there is general rules that you can follow to seting it up right. For your whooped up, deep lined rough track your going to want to set up your ride hight fairly high on your shock settings. On high speed tracks you want your ride hight lower for betting center gravity. For your frame pitch i like it anywhere from 1/2 - 1- 1/2 rise. You dont want It angled too much becouse it can throw off your weight distribution. Basically try it out and find out where its where you need it. If you cant tell the differance then dont worry about it couse you aint going fast enuff yet.

"there is a point behind it and its usually to run a longer shock which increases travel."
just wondering where you got this quote, becouse this is the most untrue statement in this post.
A longer shock does not really make it "longer travle", at ALL. Actually the shock body length has NOTHING to do with your travle.

[fast_man58]

Originally posted by yfzracer86@Dec 10 2005, 04:01 PM
first id like to say you have came up with some DAMN good information and from reading your post i have def. learned a few things i did not know myself. I also saw some false information that i would like to clear up.

"for MX, your going to want the back frame rail where the pegs mount up to be 7" off the ground.* then, take a measure 5" towards the front of the bike on the lower main rail.* this reading should be 7 1/4"* meaning for every 5 inches you move up towards the front of the bike, it should raise 1/4".

No, this is totally untrue. There are many variables when it comes to setting up your ride hight. There is no, and will never be a standard Setting for anything on suspention, but there is general rules that you can follow to seting it up right. For your whooped up, deep lined rough track your going to want to set up your ride hight fairly high on your shock settings. On high speed tracks you want your ride hight lower for betting center gravity. For your frame pitch i like it anywhere from 1/2 -* 1- 1/2 rise. You dont want It angled too much becouse it can throw off your weight distribution. Basically try it out and find out where its where you need it. If you cant tell the differance then dont worry about it couse you aint going fast enuff yet.*

"there is a point behind it and its usually to run a longer shock which increases travel."
just wondering where you got this quote, becouse this is the most untrue statement in this post.
A longer shock does not really make it "longer travle", at ALL. Actually the shock body length has NOTHING to do with your travle.

[snapback]337132[/snapback]

cool yfzracer86 im glad sombody could clear that up. i wasnt 100% sure about the ride height, so i just started reading as many posts as possible and thats what i could come up with. but thanks for getting that clear

about the shock length, i kinda worded it wrong, and its from a long while back. but its just the general statment that the "long travel front ends" are using a longer shock, thus making them "long travel". but the shock body length will have some effect on the travle. iv seen some Elkas with extreemly long bodys and only about 3 inches of shaft exposed (plus the bump stop), and if they were to have a shorter body, then the shaft travle length could be greater, giving you more wheel travle. but perhaps it was just because the design of the arm called out for a shock like that. i dunno?

anyway, thanks for the clarification