Shock travel Ratio

[firefighterjosh]

OK the front of my king quad has 7.1 inches of travel. I can put Stock YFZ450 front shocks on it that have 9.1 inches of travel with no problems with CV joints binding.

Now the rear of my king quad have 8.1 inches of travel but the 9.1 inch travel YFZ450 shocks will bind the CVs.

Now the angle of the shocks after mounting are what cause this. Does anyone know how to mathmeticaly figuer out the shock ratios so I can figer out what shock travel I need for the rear of my king?

Thanks, sorry hard to explain.

[bradley300]

i think i get what your after, so here goes.

you dont need a ratio, all you need is a shock with the correct stroke, extended and compressed length.

measure full extended and full copmpressed lengths (*add a quarter inch each way so you arent landing on the ball joints) if your cv's bind either way before that, stop before they bind and measure from that position.

then subtract the extended from the compressed and that is your stroke.

i would say the YFZ shock has too much extended length and compresses too much, so either problem can be fixed with a re valve once you have the correct numbers to give the shock builder. they will probaly need some other measurements, but they arent hard

[firefighterjosh]

The YFZ450 shocks work up front. Many people have done it. But they say the angle of the front is diffrent then the rear which makes a diffrent ratio which can give it less travel then the shock intends. Its very confusing. But I will try your idea too.

[bradley300]

Originally posted by firefighterjosh
The YFZ450 shocks work up front. Many people have done it. But they say the angle of the front is diffrent then the rear which makes a diffrent ratio which can give it less travel then the shock intends. Its very confusing. But I will try your idea too.

the issue is the shocks dont decide the amount of travel, the frame does. the shocks will travel only as far as the geometry of the quad lets it

i know my way will show you how much travel you have available if the shocks are set up for the quad.

[400exrider707]

You're reverse engineering this... you're supposed to build the shock to work on the quad, not build the quad around a set shock. Have you thought of getting some custom shocks made? May cost a little more but probably well worth it. Or like Bradley said, get the YFZ shocks, get your measurements and get them built to work on your quad. I would call someone and talk to them about it. After all you are going to be paying good money for shock setup, might as well put that money to good use and let the shock builder do all the hard work.:cool:

[firefighterjosh]

Works and Elka make shocks for my quad. I am just trying for a good set-up cheap.

I have YFZ450 fronts.

I will try bradlys way

[firefighterjosh]

Originally posted by bradley300
i think i get what your after, so here goes.

you dont need a ratio, all you need is a shock with the correct stroke, extended and compressed length.

measure full extended and full copmpressed lengths (*add a quarter inch each way so you arent landing on the ball joints) if your cv's bind either way before that, stop before they bind and measure from that position.

then subtract the extended from the compressed and that is your stroke.

i would say the YFZ shock has too much extended length and compresses too much, so either problem can be fixed with a re valve once you have the correct numbers to give the shock builder. they will probaly need some other measurements, but they arent hard

So are you saying just compress the suspension until it bottoms out (still on quad) and measure the shock, then let it hang and and measure to get my numbers?

[bradley300]

Originally posted by firefighterjosh
So are you saying just compress the suspension until it bottoms out (still on quad) and measure the shock, then let it hang and and measure to get my numbers?

completly forget about the shocks for now, you are thinking ahead of your self. get the measurements then have the shocks built to fit, or find shocks that already share the numbers you need. the stock shocks also leave alot more room between when they bottom vs. when the balljoints bottom than the aftermarket companies will, thats why you can get a little more travel with just aftermarket shocks, even with stock a-arms

take the shocks off and lift the rear up so the a-arms hang freely and the balljoints wont go any farther. measure from the upper shock mount to the lower, then subtract a quarter inch. this will be your extended length. (you add the quarter inch to make sure the shock will bottom before the balljoints bind)

for the compresed length keep the shocks off and let the quad sag. w/o shocks it should sag down until the balljoints bind. measure again from the upper shock mount to the lower, then subtract a quarter inch. thats your compressed length.

*you could run into a problem here. if your quads frame sits on the ground before the balljoints bind, measure your compressed length with the rame 1.5 inches of the ground

or the easy thing to do is call elka or works and ask them what they are using for extended and compressed lengths for your quad;)

[firefighterjosh]

Thanks man, Got it!:D

[bradley300]

sweet, glad i could help!