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Hophead
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OK...1st of all I did search :flipoff2: Found some good stuff but wanted to just see if my thinking was flawed or not.

Now that the Samurai is finally soa'ed etc I want to measure for the correct length shocks...ie ones that won't limit my travel. Now for extension I figure I can just hi-lift the side of the truck up till the wheels come off ground, measure that and thats at least as long as I want the shocks to be, that all make sense so far?

Now my real question is with the opposite side be as compressed as it would ever want to go or would/could there be more compression available? I'm just not sure if meauring the low side will give me the correct short length.

thoughts, answers, flames??? :)
 

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Find 2 forklifts, place a forklift at the left rear wheel and one at the front right wheel, lift the vehicle off of the ground (all tires) now take measurements at droop and at compression, should tell you exactly what you need to know.
 

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Slowerthanu said:
Find 2 forklifts, place a forklift at the left rear wheel and one at the front right wheel, lift the vehicle off of the ground (all tires) now take measurements at droop and at compression, should tell you exactly what you need to know.
not quite exactly what you need, you have to take into account weight transfer and extra force from momentum. I would flex on an obsticle then measure each side, then flex the other end of the vehicle and do the same. After you do this add a little extra to the measurments for safety, and or plan your bumpstop location accordingly.
 

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For extended your method sounds good - just add a little bit to the measurement - as it will flex more down if force.

For the compressed measurement - if you could compress it to the bumpstops you'd have a good measurment, subtract a little as the bumpstop will compress. Dare I recomend a ramp to get a full compression situation?? I have seen a forklift used to keep lifting one tire until the opposite side was compressed.
 

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Joe_W said:
OK...1st of all I did search :flipoff2: Found some good stuff but wanted to just see if my thinking was flawed or not.

Now that the Samurai is finally soa'ed etc I want to measure for the correct length shocks...ie ones that won't limit my travel. Now for extension I figure I can just hi-lift the side of the truck up till the wheels come off ground, measure that and thats at least as long as I want the shocks to be, that all make sense so far?

Now my real question is with the opposite side be as compressed as it would ever want to go or would/could there be more compression available? I'm just not sure if meauring the low side will give me the correct short length.

thoughts, answers, flames??? :)

that's pretty much what I did for my cheap monroe shocks.

(just for ref): mine are *aprox* 24" @ full extention/14" at full compression, and about 4.75" of stem showing @ static ride height (I could be off a little with those, but it's close)

no mad flex/travel or anything, but they don't bottom out and limit up or down. works ok for me........for now:D
 

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After I got done with my SAS I took my truck out and crossed a dried mud trench at 45* to get it flexed and then measured and took some digi photos. then I went back to the shop and welded in the bumpstops and measured again. Last I got the longest shocks I could get without breaking the bank and made custom towers to prevent limiting travel in either direction based on my measurements.

Measure twice cut(and weld) once.

It actually came out dead nuts on. I have about an inch before bottoming on compression.
 

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Hophead
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Discussion Starter #7
Ok..leads to further question...bumpstops, at what point should they be installed (point as in at what height?) I've never really understood the science behind them. I understand the are to prevent over-compression (right?) but what is correct height?
 

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Not everybody has two fork lifts available. Another way to do compression is to use a floor jack under the axle. Wrap a chain around the frame and then around the jack. As raise the jack it will squeeze the frame and the axle together. Just be carefull. There are some pretty good forces in effect.

I did it on my Zuke w/ toy axles and was able to get it dead on.
 

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OK here is what I did for compression that worked for me.....
I popped a ball hitch in the rear reciever and connected a car trailer to it...
Then I drove a truck all the way forward on the trailer (Max tung weight)....this method is real safe...and works for the front too if you have reciever mounted up there..
 

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If your upper and lower shock mounts are already in place, then the extended measurement is of little use. Just get the compressed length required by ramping the rig, subtract a little (3/4" to 1") and establish this as the compressed length for the shock. Then refer to the shock catalog and select the longest shock that matches your compresses length number.

The extended length is a consequence......;)

OK, some will say that this could lead to the shocks max traveling on full extension. However, this is a relatively rare situation, only found on rigs with massive travel. Also, on a leaf sprung rig, the hanging weight of the axle is at least partially suspended by the springs, so the shocks won´t see the full pull of the axle weight.

On my coily Samurai, my shocks do in fact max travel on full twist. But full twist is a rare enough occurance for my wheeling that I have had no problems. Also, my suspension starts to bind at around this point, so the down travel velocity is dampened before the Ranchos come to their extended limit.

But I am looking into limiting straps, just the same.....:p
 
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