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axle

I think it is at least 6" at the axle.
 

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The biggest rule of thumb I've learned from building link suspensions is that there are no rules of thumb. Every vehicle is going to be different and for that matter every driver is going to like somthing different. A lot of times following the "rule of thumb" on this board can get you into a mess. Just my $.02
 

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You want as much as you can get. Extra verticle seperation at the axle does not prevent you from dialing in any of the good performance features of a link suspension. The only place it hurts you is in making things clear. The good thing it does is reduce the forces, stresses and deflections that the links, joints and tabs see.

6 inches could be fine if you use big heims, with rubber bushings you would want more. the ratio formula from tire size is good it will keep you out of trouble, but if you need to use less for clearance reasons you can design around it, and if you can fit more you should use it.
 

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That is the best description that I have heard in a long time..
 

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badboyblazer said:
Your separation at the axle should be 25% of your tire dia. 40" tires should have approx. 10" of separation at the axle
I had never seen this until the Petersens article, and looking through any book, I've never seen any formula that could be turned into this. I'd love to know where this one came from, as I rarely have seen this much vert separation.

As usual, I like Gordon's answer better.
 

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Gordon said:
The good thing it does is reduce the forces, stresses and deflections that the links, joints and tabs see.
not to pick but...wouldn't the mounts/tabs see more stress in exchange for less force on the links/heims?

The 25% tire thing is just a estimation, a pretty good one. Throw all these rules of thumb out the window and just use the damn 4-link calculator!!!
 

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CJ Lagos said:
not to pick but...wouldn't the mounts/tabs see more stress in exchange for less force on the links/heims?

The 25% tire thing is just a estimation, a pretty good one. Throw all these rules of thumb out the window and just use the damn 4-link calculator!!!
Be more stress where the mount attaches to the axle.
 

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CJ Lagos said:
not to pick but...wouldn't the mounts/tabs see more stress in exchange for less force on the links/heims?

The 25% tire thing is just a estimation, a pretty good one. Throw all these rules of thumb out the window and just use the damn 4-link calculator!!!

the frame side mounts see less stress, since the links see less stress.

on the axle mounts, the highest bending moment on the mount, is at the part closest to where it attaches to the axle. If the lower links are in the same place and the upper link is moved up to increase the verticle seperation then this bending moment remains the same. So for a similar designed bracket the stress would remain the same on the axle side mounting brakcets. If you increase the verticle seperation by lowering the lower links then even those stresses are reduced.
 

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Nope..

:flipoff2:


Gordon beat me to it.... ;)
 

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GoingOffRoading said:
The 25% thing is new to me but I knew about (for the most part) on the axle, more seperation the better. What about at the frame?
do what will get the geometry where you want it.

The axle is applying the force so changing the mounts at the frame isnt going to change the amount of force the axle can assert
 

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I am working on my buggy rear 4 link right now and that calculator thing seems kinda neat. If you know where to plug in all the #s.

There are so many posts about this, it hard to tell good info from the bullshit.
 

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the 4link calculator makes link suspensions so much easier and so much less to learn, but if you want to make things even simpler than that, I've heard many people very pleased with their suspension following the rule of upper links 75% of the length of the lower links and seperation at the frame 75% of seperation at the axle.
 
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