shock settings

[doubleu82]

Hello all!

Even though I work from my home, I decided to take yesterday and today off to wrench on my bikes. I previously cut up 2" x 3/16 flat iron and made brackets for my footpegs to sit up 2" higher. I had to cut my rear brake foot rest in half so that my kickstarter would clear.

Yesterday I cut up 1 1/4" x 1/8" angle iron to make brackets for my new XMR supplied FastAce shock. All went well and bolted up right. I just rode it around to feel the difference in the shock and I can honestly say I don't know what I'm supposed to feel. :confused: I started out by pumping up the shock to 80 psi since it's rated for 50-200. I've got a static sag of 1 1/4". I have the 750 lb spring that it came with because the x18 spring is too small for the 7 1/2" long shock. I played around with the rebound and compression settings, but I'm not sure what I'm aiming for.

So for those who own air/oil/coil shocks - how should my bike ride when it's set up properly? In what order did you make changes - air, spring, compression, rebound?

[swheels]

Since Blitz has that same shock he should be of some help.But if you can't tell the difference some is definitely not setup right with the shock.The diference should be like night and day.Also you can get a 1500lbs spring off of ebay for dirt cheap.They might be long enough to fit that shock.(ask the seller just incase).

I put over 200psi in the ones i used.If your at 80psi's,i'd go up in 10psi increments until you feel the difference.

[Blitz$M.Inc.$]

well when i raced, it was on soft and i forgot what the rebound was, lol i dont even know the pressure, isnt that bad
ill say this, when i first put it on, i was like wow, it was more 'stable' and Cadillac feeling, so i didnt change anything and just learned how to ride it like it was
i have a 1500lb spring tho, with the 750 it dropped to the floor

[doubleu82]

Blitz maybe yours didn't have much air in it. I pumped it up to 80 before I put it on and it never bottomed out. I measured the eye-to-eye sag and it was only a 1/2 inch or so. It's definitely different than the stock shock. I sat on hubby's bike and it went down fast and sprang back up like a pogo stick. I sat on mine and it eased down and came up also with a controlled movement. I'm just not certain what my end result should be. Is there a feeling that I'm aiming for? When I roll off a curb, what ideally should the suspension do?

[X-18]

I have 5-5/8" Fox Vanilla RX (5/8" too long), but here are some settings that could be a starting point for you. I don't have compression adjustment, but I'll include it incase you do. You could probably search Fox Vanilla and find some PDF's too.

Coil Over Shocks

General Set-Up Instructions

To get the best performance from your FOX Racing Shox, it is necessary to adjust SAG. On the coil-over shocks this is done by adjusting the spring preload or changing springs. SAG is how much the shock compresses when you sit on the bicycle. Increasing spring preload will make the shock compress less. Decreasing the preload will make the shock compress more. The smoothest ride will be achieved with one turn of preload. (Note: it might be necessary to change spring rate to achieve the proper sag setting.) Adjusting sag setting is easiest with two people, the bike rider and an assistant.


Step 1. Measuring SAG

Measurement #1

Measure the distance from the center of one mounting bolt to the center of the other mounting bolt. Record this measurement.

Sit on the bicycle in a normal riding position. Your weight should be on the saddle with your feet on the pedals. It will be necessary to hold yourself up against a wall or post to steady yourself. Make sure your weight is distributed on the saddle and pedals as it would be in your normal riding position. Do not bounce on the pedals or saddle.

Measurement #2

Have an assistant measure the distance from the center of one mounting bolt to the center of the other mounting bolt while you are sitting in the riding position on the bicycle. Record this
measurement.

The difference between measurement # 1 & measurement # 2 is the SAG.

You can determine shock travel by measuring the exposed shaft length of your shock. Slide the bottom-out bumper to the middle of the shaft and measure the exposed length. This is your shock travel.


shock travel----shock travel------SAG--------------SAG
--(inches)------(millimeters)---(inches)-------(millimeters)

---1.00-----------25.4-------------.25--------------6.3
---1.25-----------31.7-------------.31--------------7.8
---1.50-----------38.1-------------.38--------------9.6
---1.75-----------44.4-------------.44--------------11.1
---2.00-----------50.8-------------.50--------------12.7
---2.25-----------57.1-------------.56--------------14.2
---2.50-----------63.5-------------.63--------------15.9
---2.75-----------69.9-------------.69--------------17.5

Step 2. Changing Preload or Spring

To set the preload, you need to adjust the spring preload ring. FOX Racing Shox recommends no more than 2 turns of preload. If more than 2 turns of preload are required to achieve the correct amount of Sag, it is recommended that the spring be replaced with a firmer rate.

Adjust preload by threading the preload ring onto the body. Clockwise turns increase preload which decreases the SAG. Counterclockwise turns decrease preload which increases SAG.
OR
Change the spring (See Installing and Removing Springs). A stiffer spring (higher spring rate) decreases SAG. A softer spring (lower spring rate) increases SAG.

Springs are available from FOX Racing Shox. Numbers are printed on the outside of the spring coils indicating the rate (in pounds) and travel (in inches). Example: 550-1.95 is a 550 pound-per-inch spring rate with 1.95 inches of travel. Please note this number when ordering replacement springs. Also be prepared with the make, model, and year of bicycle, shock travel, rider weight and riding style.

Repeat Steps 1-2 until proper SAG is achieved.

Rebound Adjustment

This adjustment will enable you to tune your shock to any spring rate or riding condition. The proper rebound setting is a personal preference and varies depending upon your weight and riding style.

Rebound Adjustment Guidelines

Rebound should be as fast as possible without kicking back and pushing the rider off the saddle when riding the bike in rough terrain. If the rebound is too slow the suspension will not have time to extend before hitting the next bump.

Compression Setting

The compression damping is changed by turning the blue rebound adjuster knob on the Vanilla RC. The Compression adjuster changes the force required to compress the shock. Turning the blue adjuster knob clockwise increases compression damping (more difficult to compress), while counterclockwise reduces the compression damping (easier to compress). During the first few rides change the compression adjuster and note the different ride characteristics. Your compression adjuster setting may change with different riding conditions.

Note: The smoothest ride will be attained with the compression adjuster in the softest setting.


Hopefully this is not too confusing.

[swheels]

Those settings might not work for a midbike.Simply because the were calculated for a mountain bike.(lighter in weight)Those settings would be to soft.

[X-18]

Is there a feeling that I'm aiming for? When I roll off a curb, what ideally should the suspension do?

"Rebound Adjustment Guidelines

Rebound should be as fast as possible without kicking back and pushing the rider off the saddle when riding the bike in rough terrain. If the rebound is too slow the suspension will not have time to extend before hitting the next bump."

I haven't raced, but I recall some of the racers here talk about the rear becoming un-weighted or bouncing when exiting corners. I guess the Rebound Adjustment Guidelines could be modified by one of Midbike Nations Racers to describe how it should feel exiting corners.

[X7rocks]

thats why with my new suspension im gonna have to have alote of time finding out what will work
all i know is i gotta switc my stock spring from my 18 out to it

[X-18]

Those settings might not work for a midbike.Simply because the were calculated for a mountain bike.(lighter in weight)Those settings would be to soft.

The weights are different, but the desired performance should be the same, IF we were to ride on tough terrain. Since most of us don't, instead of applying the "rough terrain" terminology, apply "exiting corner".

I may be wrong, but this works out in my mind. It's all relative.

[doug@xmr]

doubleu82 you can call any time for tech whatever question you have is a good question. Me personally, I prefer a stiff rear with the rebound set so that the tail almost completely rebounds then slows for the very last inch of movement at the shock. I'll check on saturday for exactly how many turns out my adjusters are at, so you can have somewhere to start from. I'm not sure if that helps but the shocks take a little while to figure out and find the sweet spot but once it's dialed in it makes a world of difference. If you've properly inflated the shock you may not have to switch the spring. In our case we normally swap out the spring and don't bother with the airpressure.

[doug@xmr]

The weights are different, but the desired performance should be the same, IF we were to ride on tough terrain. Since most of us don't, instead of applying the "rough terrain" terminology, apply "exiting corner".

I may be wrong, but this works out in my mind. It's all relative.

Actually your pretty close the shock eliminates the bouncing fealing that you get from the stock suspension. Without the rebound adjustment the suspension would just keep bouncing and the faster you go the more unstable the bike becomes. No imagine that same effect but leaned over in a corner not fun. The more motor you add to the equation along with the stock tires the worse it gets.

[doubleu82]

doubleu82 you can call any time for tech whatever question you have is a good question. .

LOL! I know when I have YOU on the phone and YOU didn't answer it yesterday. bluelaugh It sounded like a younger guy. He needed convincing that I bought the shock from your company. I asked him how much pressure should I put in it and, after putting me on hold so that he could ask someone else, he told me 50 psi. rolleye0010 It's all good though.

Thanks for the help X-18. I actually printed out the Fox manual earlier in hopes of understanding what I should end up with. I figure this is going to end up like my carb experience. That took forever for me to dial in, but once I did I learned the ins and outs of how carbs works. So I'll be a suspension expert after this. thumbsup2

[X-18]

thats why with my new suspension im gonna have to have alote of time finding out what will work
all i know is i gotta switc my stock spring from my 18 out to it

What's up X7. How is it going in Northern - Southern Maryland. Here is that Fox Vanilla RX I told you about when I was up there. It only measures 5-5/8" eye-to-eye, but it still raises the rear too much. Without me on it the chain touches the swingarm pivot. I'll have new mounting eyes welded one day.

[swheels]

The weights are different, but the desired performance should be the same, IF we were to ride on tough terrain. Since most of us don't, instead of applying the "rough terrain" terminology, apply "exiting corner".

I may be wrong, but this works out in my mind. It's all relative.On a smooth track you won't the suspension being stiff.On ruff terrain you want the suspension to soak up the bumps just the opposite.Manufactures making these shocks more than likely had no idea people would be buying them to use for the midbikes.Fisrt off the mids are easily over 120lbs.That plus the rider close to 300lbs the settings are gonna be way different.

[doug@xmr]

LOL! I know when I have YOU on the phone and YOU didn't answer it yesterday. bluelaugh It sounded like a younger guy. He needed convincing that I bought the shock from your company. I asked him how much pressure should I put in it and, after putting me on hold so that he could ask someone else, he told me 50 psi. rolleye0010 It's all good though.

Thanks for the help X-18. I actually printed out the Fox manual earlier in hopes of understanding what I should end up with. I figure this is going to end up like my carb experience. That took forever for me to dial in, but once I did I learned the ins and outs of how carbs works. So I'll be a suspension expert after this. thumbsup2

So does that mean I sound olddunno lol...Sorry was in Jersey all day

[doug@xmr]

What's up X7. How is it going in Northern - Southern Maryland. Here is that Fox Vanilla RX I told you about when I was up there. It only measures 5-5/8" eye-to-eye, but it still raises the rear too much. Without me on it the chain touches the swingarm pivot. I'll have new mounting eyes welded one day.

That shock new is pretty expensive. Jag used this same shock on his x-18 V. Rossi replica with the 100cc 2-stroke motor. Works great!!

[doubleu82]

So does that mean I sound olddunno lol...Sorry was in Jersey all day

Naw! You don't sound like you're waiting for the next wave. bluelaugh

[X-18]

You're welcome doubleu82. I don't post often, especially about techincal stuff, but when I do I try to know what I'm talking about. This one was not from experience, but from reading the post of you racers on here and reading the function of the shock.

bows_smilieKeep up all the good work you're doing doubleu82 (everyone Blitz, sWheels, Nutty, Shooter, X7, x18 (not me "X-18"), Stuntn, and all those I forgot). All of ya'll are an inspriration. I was about to give my X18 to my brother since I've had a couple 1:1's after a feeble atempt to make the X18 street-legal. Then I got on here and had a fire put under my butt, well actually there is smoke, but no fire yet. I'll get there thumbsup2

And Doug, Mr. XMR, thanks for the semi-confirmation:) I must pay you a visit! Since I've been on here I try to think of a reason to drag my fam by your shop on the way to Front Royal. I think I have been back where shop is years ago. I bought a lot of Redline fluid for my car from a race shop, I can't remember the name. But I will find you, I must find you! I'm thinking about that 178cc Scut kit and Takegawa R head with Race Cam and Race Port & Polish. Is that overkilldunno Don't get too happy though. It will be a while before I can make that move. I don't know about the national economy but my personal economy is in a depression, yep with a "d"

[stuntnx7]

You're welcome doubleu82. I don't post often, especially about techincal stuff, but when I do I try to know what I'm talking about. This one was not from experience, but from reading the post of you racers on here and reading the function of the shock.

bows_smilieKeep up all the good work you're doing doubleu82 (everyone Blitz, sWheels, Nutty, Shooter, X7, x18 (not me "X-18"), Stuntn, and all those I forgot). All of ya'll are an inspriration. I was about to give my X18 to my brother since I've had a couple 1:1's after a feeble atempt to make the X18 street-legal. Then I got on here and had a fire put under my butt, well actually there is smoke, but no fire yet. I'll get there thumbsup2

And Doug, Mr. XMR, thanks for the semi-confirmation:) I must pay you a visit! Since I've been on here I try to think of a reason to drag my fam by your shop on the way to Front Royal. I think I have been back where shop is years ago. I bought a lot of Redline fluid for my car from a race shop, I can't remember the name. But I will find you, I must find you! I'm thinking about that 178cc Scut kit and Takegawa R head with Race Cam and Race Port & Polish. Is that overkilldunno Don't get too happy though. It will be a while before I can make that move. I don't know about the national economy but my personal economy is in a depression, yep with a "d"




im sure with gas prices the way they are these bikes will be poppin up street legal more and more often in the next year or 2 so it'll proly start getn easier to get em streetable

[X-18]

On a smooth track you won't the suspension being stiff.On ruff terrain you want the suspension to soak up the bumps just the opposite.Manufactures making these shocks more than likely had no idea people would be buying them to use for the midbikes.Fisrt off the mids are easily over 120lbs.That plus the rider close to 300lbs the settings are gonna be way different.

You are correct. That is why I said it is a starting point and also said to substitute "rough terrain" for "exiting corners". The weight delta will not matter once the proper spring and air pressure are achieve. The designers of the frames, Mountain Bike and mid bikes, took the frame geometry into account to use a shock. If we change shock lenghts, we should keep the frame geometry the same by moving mounts in proper directions or we will have chain issues, at the very least. You should not move the mounts JUST up or JUST down or JUST fore of JUST aft. The after-market shock should retain the original angle of the stock shock unless you want different chassis characteristics not attributed to the rear suspension.

Weight should not matter once the proper sag and rebound are achieve for the rear shock. You do this with springs and pressure (air, nitrogen, any other inert gas you wish use with the proper properties).

Before I said that you were correct, but depending how you look at it you could be wrong.

Q. What is the purpose of a performance shock?
A. To keep the drive wheel on the ground as much as possible to efficiently power the vehicle forward. Be it a Mountain Bike on rough terrain or a Mid Bike on a smooth track.

Hypothetical Situation

Mountain Bike(35) and rider(150) weigh 185 lbs
-to get the proper sag adjust the preload ring 5 turns
-to get the proper rebound add 50 lbs of pressure

Mid Bike(120) and rider(150) weigh 270 lbs (with the same shock)
-to get the proper sag adjust the preload ring to 2 turns
Why only 2 turns? Because the Mid Bike frame is already applying some preload to the spring and the riders 150 lbs has less of an effect on the spring
-to get proper rebound add 100 lbs of pressure
Why 100 lbs? Because the shock has to lift (rebound) more weight

Now that could be looked at as opposite or merely different magnitudes.

Another Hypothetical

I believe that on a smooth track you may not need to soak up the bumps, but you do want to soak up and distribute the power that you are putting down

-Select your optimum riding height of your Mid Bike
-Put a solid bar in there to replace the shock
-Take a competitve run
---What happens with a competitive engine?
------You feel the rear wheel sliding out in corners
---------Why?
------------Sliding left or right has less resistance than going forward or hopping towards the sky
---What happens with an even more competitive engine
------Your rear wheel hops out of the corners
---------Why?
------------Hopping towards the sky has less resistance than going forward or sliding left or right.

Now put a shock in there, even the stock X-18 shock, and you will have less of the hopping and sliding and more of the forward movement.

I am new to the game and have not raced, I am sure that you can some racers, what if my shock is to stiff? Why is my rear wheel hopping coming out of the turns? Why is my wheel sliding out? Answer - If it is not too much rebound, your shock is too stiff

It is all physics pertaining to magnitude and relativity.

OK that is the end of my explainations, guesses, whatever you want to call it.

[CAM2]

Dub I bought The Super GS-57 Air adjustable rearshock;-took out the 750lb spring and swapped in the 1500lb one from the stock shock.The GS-57 shock is air adjustable/height adjustable and rebound is controlled on how much you crank the spring and the amount of air pressure.Shocks with all those other fancy setting are designed mainly for dirtbikes.The height on the GS-57 supershock adjusts from 8 3/4" to 9 1/2".

I Put the shock with 1500 lb spring in my X-15 and set the shock for 9"-9 1/4" and it gave me a footpeg height of 11" from footpeg bottom to the ground.But the bike had a nosedive problem so I added a taller tire in the front a Kenda K413 90/90/10.In the rear I put a Kenda K413 130/70/10 and I dropped the forktubes 1/4" down.I also had to lengthen the kickstand 3" longer so the bike can sit good.The bike handles flawlessly up to 55-65 then the swingarm gets rubbery around 75-80 but still handles relatively stable;-compared to the stock unadjustable suspension it came with. Peace

[doubleu82]

I seriously lucked out and won the 1,500 lb spring off ebay for 20 bucks. Everything is all installed now and I see a tremendous difference between the stock shock and my Fastace shock.

WARNING for those who want to upgrade: finding a 1,500 lb spring was like finding a needle in a haystack. I even called Fox to see if I could order one direct. Nope. They don't make them rated that high anymore. Stick with the 6 1/2" shock so that you can use the X18 spring.

[swheels]

That's great to hear Dubs.At one time they use to have tons of those 1500lbs springs on ebay.The only other bike i could think of that uses such a long 1500lbs spring.Is the x12's i'm soory but it just came to me after looking at some pics of one on ebay.dunno