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Discussion Starter · #1 ·
I don't know if my theory is correct or not, but the physics seem correct.

Our quad seem to have a weight balance with a bias towards the rear. Baxter just posted some numbers that show more weight over the rear wheels than the front wheels.

With stock size tires front and back (22" & 21"), our quad sits level with the ground.

I know that I can raise or lower my ride height by adjusting my pre-load on my Elkas.

My idea is to lower the front by 1/4" and raise the back by the same 1/4"... giving a total of 1/2" difference and thereby shifting some weight forward. At times, my front wants to lift a bit when I'm on the power hard... like the low range of 3rd gear... pulling hard, the front wants to get light and can be kinda dicey unless you're going straight. This is not the IRS push issue... more to help the front end stay down better under hard acceleration.

Sound idea? I ask because I've only been riding 3 years and don't know. Thing is... There are members here that know lots more than me. (most members)

roadkill
 

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I don't really know the answer to this, but I know Fox recomends dropping the front 1". When I get my shocks later this week I'm gonna try it and see how it does.
 

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I've tried to come up with an opinion on this, and I'm stumped. Here's the deal--in road cars, the surest way to steer quicker is to move weight BACK. That's why F1 cars and such are mid-engined. If the center of gravity is further back, the steering tires have a longer lever arm to act against, so they can move the front end around easier. But, the less weight up front, the less friction available to the tires, so maybe it becomes something of a balancing act. And maybe normal car behavior doesn't have anything to do with how an off-road vehicle handles stuff. I mean, our rear axle is always locked, so there's always slippage there, so maybe that throws asphalt handling rules out the window.

So, short answer--I don't know, dammit, and now I need a drink.
 

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I know everything I have ever learned, read, etc. about quad setup is you always want the rear of the quad lower then the front. With the rider on the quad, you want to measure from the frame to the ground both at the front and rear of the frame. (For the front, I measure under the front motor mounts, rear under the foot pegs.) You want the front to be about 1/4" to 1/2" higher then the rear. Not really sure why this is the case, but it is pretty common practice in the quad world. I would think lowering the front end would make for some strange handling under hard braking, quad may "stink bug" alot more then normal, but I have never tried it, so it may not be a big deal.

I have been told the front to rear balance of the 700XX is pretty good, it is the fact the stock front end has alot of castor is the reason it doesn't like to turn. I guess the front coming up is another problem though, but can't say it is a problem I have. I learned long ago on my 450R's that when getting on the gas, I transfer my weight and sit at the front of the seat/rear of the gas tank to help keep the front down, just something I have learned over the years.

One thing I have learned setting up a quad for three different riders is everyone likes something different. It took me a couple of years to find a suspension setup that all three of us were happy with. (happy might be to strong of a word, "live with" might be better!)What one person loves, another will hate. Best thing you can do is experiment, try different things and see what works for you. I know if I was the only one riding my race 450R, it would have a slighly different setup on it.

Doug
 

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i dont think is so much a weight issue as it is being able to adjust your camber and caster of your front tires. when your under power the weight is shifted to the rear even at slow speeds you can see the front end pull up. being able to adjust thoses is what helps the most at high speeds. just some reading ive done.lol
 

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I run 22'' tires all the way around, and w/ the DS450 shocks I have them as low as they go so that the angle between the front to rear isn't not as severe. I did this to try and limit the weight in the rear b/c just the look of the quad you can tell it is heavier in the rear. I agree with Doug about the setup of most quads, but this is not most quads. This is a completely different animal than those SRA's. Just look at how the frame comes back straight the whole way and then how much the rear shocks whether they are stock or aftermarket compress compared to that of a SRA (I am not saying that you don't want that, but w/ this I would think you could go perfectly level). However, if you were to go lower in the front that you are in the rear then I would also think it would be pretty squirrelly under different conditions. I tried to level mine as much as possible, and it still sits up a tad in the front, but it has helped a lot w/ the accelleration out of corners to prevent the wheelies and stuff. This is just my 2 cents obviously, but I tried all different things last winter when I had everything tore off from it, including the engine out of it so you can see everything much better. One of those cold winter days where I got bored lol.
 

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I also run 22" all round and run 12" clearance all round. I measure from the rear of the front a-arms and front of rear a-arms. I have also tried far too much on settings for the suspension. I have been trying 14 months and still not figured it out and agree SRA settings dont work.
I found raising the front higher than the rear makes the rear end loose, Good for mx. Lowering the front below the rear makes for scarely accurate steering to the point where the 700xx will make the corner but you may not. I learnt to grip with my knees for this one. Good for tree dodging . Setting equal front and back is a compromise as I use 1st and 5th in the same lap. This maybe just the setup I am running . :D

Also Doug is right about suspension setting , there as personnel as the type of mobile phone you have.
 

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I am gonna try something. I know you can't really compare an sra quad to irs but my buddy races a 450R, and my uncles race dirt track cars. I am going to try to take my buddies ride out to my uncle to scale it, his scales measure how much weight each tire is carrying. Then I'll put mine on dead factory. Se what the difference is. There's gonna be a lot, sounds time consuming but should take like 5 min.
 

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I am gonna try something. I know you can't really compare an sra quad to irs but my buddy races a 450R, and my uncles race dirt track cars. I am going to try to take my buddies ride out to my uncle to scale it, his scales measure how much weight each tire is carrying. Then I'll put mine on dead factory. Se what the difference is. There's gonna be a lot, sounds time consuming but should take like 5 min.

Love to know how you get on !
 

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Im running 23" fronts and 22" tires out back. Right now I have the ride height 1/4" higher up front because that's what i heard was a normal set up. The front is 11-1/4" behind engine mount and the rear is 11" at the pegs and i have elkas in the front and stock rear. I never really experimented with higher or lower front end but would like to know what you guys find.
 

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Are you guys taking the measurements while sitting on the quad in your usual riding position? I was going to measure mine and that seems like the scenario that I should be concerned with.
 

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If ur hard on the gas its gonna be lite on the fronts no matter what. It will be impossible it stop it without crazy suspension mods, cause the irs gets mad traction. Just my thoughts.
 

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My theory.......weight balance front to back is not altered much when changing ride height of the quad. It slightly changes the centre of gravity (COG) of the quad but not much.

IMO the biggest change in COG can occur when you change ride height that makes you change the way you sit on the quad.

A lower ride height at the front will move your body forward changing your COG making the quad more flickable but less stable at speed.

BUT.......

You can change your COG without changing ride height. IMO this is the key to an all round good handleing quad.

So the question is; do you want to change your ride height or do you want to change your COG?

Linc
 

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the ride height changes the weight distribution by the fact that adjusting the preload effects how hard the spring pushes against the ground, the easiest way to see this is get 4 scales and put them under each wheel, with someone similar weight and riding position to you, adjust the preload and watch the scales move, putting more preload on the right hand rear will put more weight on the left hand front tyre, and to take weight off the front you can add more preload or back the preload off the diagnional corner

i have lernt and seen this setting up several sprint cars, super sedan and late models for speedway,
 

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the ride height changes the weight distribution by the fact that adjusting the preload effects how hard the spring pushes against the ground, the easiest way to see this is get 4 scales and put them under each wheel, with someone similar weight and riding position to you, adjust the preload and watch the scales move, putting more preload on the right hand rear will put more weight on the left hand front tyre, and to take weight off the front you can add more preload or back the preload off the diagnional corner

i have lernt and seen this setting up several sprint cars, super sedan and late models for speedway,

OK, so preload affects ride height by eliminating some sag, and moving ride height up in one corner does shift the weight toward the opposite corner. But the whole pushing down harder on the ground thing isn't really possible--you've only got a set amount of weight. Replacing the shocks with a rigid structure of the right compressed-shock length wouldn't affect weight distribution, but adjusting the height of that rigid element would.

Edit: Of course, all this gets thrown out as soon as you're in a dynamic situation. So when you're moving, the different preload absolutely affects how hard the shock pushes against the ground. Is that what you were getting at?
 

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Discussion Starter · #17 ·
Thank you all for your answers and opinions. This is exactly why I asked the question... because it had not been discussed before. Plenty of discussion about front end push and stuff like that... but nothing on ride height and weight balance.

roadkill :thanks:
 

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OK, so preload affects ride height by eliminating some sag, and moving ride height up in one corner does shift the weight toward the opposite corner. But the whole pushing down harder on the ground thing isn't really possible--you've only got a set amount of weight. Replacing the shocks with a rigid structure of the right compressed-shock length wouldn't affect weight distribution, but adjusting the height of that rigid element would.

Edit: Of course, all this gets thrown out as soon as you're in a dynamic situation. So when you're moving, the different preload absolutely affects how hard the shock pushes against the ground. Is that what you were getting at?
its hard to explain, i think you sort of understand what im on about, its the way i had it explained to me, the thing with the scales is a good way to see it in number form but wont really help setting up for the track but it will give you a understanding of how to shift weight,
 

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its hard to explain, i think you sort of understand what im on about, its the way i had it explained to me, the thing with the scales is a good way to see it in number form but wont really help setting up for the track but it will give you a understanding of how to shift weight,

You are right with your preload effects weight balance theory but it's worth noting that preload and ride height are different things have different effects when adjusted.........the big problem with the XX is preload & ride height are adjusted at the same time and this is a huge compromise.

More preload at the front makes the front springs push the wheels on to the ground harder.......weight to the front.........

BUT..........increased ride height at the front will move weight back mainly due to body possition and the change of COG.

If you want to move COG without changing ride height or preload can I suggest that you experement with moving your bars forward or back........a few mm either way can make all the difference.

COG and suspension performance can be effected by just about anything from bar height and sweep to possition of the pegs shape of the seat foam.

Confused........????????.........thats why people get payed to do this stuff. Good subject and great to get everyones personal experience with adjustment and effect.
 

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If ur hard on the gas its gonna be lite on the fronts no matter what. It will be impossible it stop it without crazy suspension mods, cause the irs gets mad traction. Just my thoughts.
Part of this is true, part of this is not. Yes, the IRS gets mad traction. The fronts wont necessarilly be light when you nail the gas. I know you are saying less traction when you accellerate, but if you lower the front to equal the back, you will be having that much more effect of keeping the front end down. Not only that, the A-Arms will be pushed out just a tad wider, therefore depending on tire, a tad more patch of rubber to the ground. Lastly, w/ the front end more level with the rear, your riding position could be more towards the front of the machine than it would normally, making more weight towards the front and helping more so w/ turning and keeping the front end down. To think about it another way, when you do wheelies say in third or fourth gear, you lean and pull backwards to bring it up right. Now when you are say in second gear, you can nail the gas and the front end will come up pretty easily. Now, riding the same speed, hit the gas in second while you are leaning forward some, does it come up? More than likely not unless you're on pavement or something.
 
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