If your shock has 11 inches of travel, would you want it mounted half way (showing 5.5 of shaft) sitting on its own weight?

I have SPOA with my lower mount at the top of the axle tube. Trying to size up my own uppers now. My spring clamp/locating plates have a lower shock mount on them which would raise the shocks another 2 inches or so as an option. Tia

I would make it closer to four inches of up travel, how you mount your shock to your diff depends on the type of driving that you will be doing, on the back side for taking off fast, on the front side for braking hard, one front side one back side for high speed Bumpy roads, you get the idea.

trail tough recommends 2" of up travel

Sizing shock is best done if you know what your suspension travel is. And the best way to do so is to remove your existing shocks and drive one tire up on a ledge or something then measure your distances. <ie full compression and full droop>

Your shock should have a little travel left after you hit your bumpstops so add like a .25-.50".

Generally you will have more down travel then up travel. Up travel is often more important for going fast bumps, jumps, and such. And most "crawlers" have little to no <edit> uptravel.

I am a big fan of 5-6" of uptravel.. I want the suspension to work for my under the rig. Imagine hitting a 4" rock at 35mph on the trail.. with 5-6" of up travel you would feel it but it won't be bad. with 2" of up travel you are really going to feel it.. I ran around with 2" of uptravel for a year or so and it was horrible.. At 5-6" it's way way way better.. But if your building a ramp champ or a hard core comp crawler.. Down travel is king.. I ran my sidekick IFS with 2" of down travel and primarily all uptravel and it worked awesome...

Just depends on what your building your rig for..

I agree with only needing 4 inches or so of up travel. You do need more droop than compression.

Plus if you angle the shocks a little, you get more axle travel than shock travel, but that is more for road driving than off road.

In compression the tires will give a lot and are part of the suspension setup, and you want a bumper of some sort or thing will break!! So between the tire and bump-stop you may really have 8-10 inches of real
 travel with just a 30 inch tire!

Measuring is the key. Make sure the splines don't bottom out or come apart!! Limiting straps might be in order along with bump stops. Don't get a HD shock for such a light vehicle, you want to control rebound is all.


 

Sizing shock is best done if you know what your suspension travel is. And the best way to do so is to remove your existing shocks and drive one tire up on a ledge or something then measure your distances. <ie full compression and full droop>

Your shock should have a little travel left after you hit your bumpstops so add like a .25-.50".
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Listen to this advice (above).

I'm reading a lot of bad advice and opinion (not real world). For example, having 4-6" of uptravel and hitting a 4" rock... has NO RELATION to the shocks travel and if it bottoms out. It would more so if your shocks were in direct 1:1 angle (and then depend on speed, shock valving...etc.etc) to the axle, but they are not (especially the rear).

Let me elaborate;
BEST and only way to determine correct length of needed shock is to get the vehicle to a rack, or forklift one tire to full compression. Measure the shock mounts, center of eye to eye (that would be bolt to bolt with no shocks on the vehicle). While it's in this position, take a measurement of the drooped side and note it too (usually the opposite corner of the vehicle). Do this for ALL 4 corners, as you'll get different measurements at each corner.

Once all 4 measurements are taken, full uptravel and full droop, take the shortest and longest measurements. Use those to calculate shock length.  For example, if you have a 14" length at uptravel, and a 21" length at full droop.... you then need a shock capable of about 8" of travel (full movement). However, the body of the shock now comes into play because you don't want it too long (which would limit uptravel).  With the vehicle sitting static, measure your distances between bump stop and axle. If it's 2", then add 2" for bump stop squish. That means you have about 4" of uptravel at static ride height.  With the shock sitting static, you want about 4.5" of shock shaft showing, and still want the shock long enough to extend out to full droop... 3.5" longer.   Make sense yet???

It's tough to always find the perfect shock, in the perfect length, with the perfect valving (for the light zuke). But it used to be Rancho RS5000 shocks were built with numbers to reference their valving AND lengths. 5010 and 5008 were most often used in multiple shock applications (soft valve), where 5100 series were single shock applications (stiffer valving). I've not used them in a long time... but, that gives you an idea. Also, most of us with missing links installed, will need a long shock capable of severe droop, without effecting uptravel due to the shock canister length.

Here's a quick link for some compressed and extended lengths (L=loop, S=stud)
http://www.my4by.com/rancho-rs5000-shock-specs-a-1.html
... did you use the chart to see which shock the above example needs??  (RS5008 or RS5118 as they are loop-loop)

And a link for mounting codes...etc;
http://www.my4by.com/pdf/RanchoMountingCodes.pdf

... if you've got the extra bucks, the 9000 series would be an awesome choice. As you'd be able to dial in your suspension for the terrain your driving on!

If you want max travel out of a Sidekick rear suspension without going thru rear shocks consider changing the lower shock mounts orientation, as it is designed from the factory, the rear axle travel applies significant side loading to the shock. I found these little gems and will be fabbing up something similar to put a stop to rear shocks blowing their guts in only a few hundred miles. http://www.bits4vits.co.uk/store/vitara-/-x90/shock-repositioners-/-spacers/prod_173.html