Shock lengths

[RamJetFSJ]

Need some input on my shock lengths. I have the following: 80 Wag 4" Rusty springs, 1" lift shackle front, 2" block rear. Ford F250 shock towers in front. (may go w/ a zero rate 1" block in the rear, as I have a slight rake right now)

Im trying to measure for and buy a set of Bilstein 5125 shocks. I have yet to only be able to measure ride height shock lengths. I hope to have full droop measurements soon. I double Ill be able to flex the suspension enough to get decent compressed lengths. I need to account for high speed compression too, as this isnt a crawler. I am having a real hard time imagining how much up and down travel these springs will have since they are pretty stiff. So heres the measurements I have, and the shocks i feel are the best bet.

Front:
@ Ride Height = 24.25" eye to eye
Approx 8" uptravel until middle of stock bump stop. If I put on extended bump stops, I figure 6-7" of up travel.
11.94" Travel Shock gives me 5.5" Down travel, 6.3 Up travel.
Next shorter shock (11" travel) would give me 3.75" down travel, 7.25" up travel.

Rear:
@ Ride Height = 20" eye to eye
Hard to approximate rear travel, as I dont remember how thick the original spring pack was, but Im guessing 6-7" of up travel if I put on some very long bump stops (currently 10" up to middle of stock bump)
10.17" Travel Shock give me 6" of Down Travel, 4" of up travel. (doesnt seem like enough up travel)
Next shorter shock (8.6" travel) only gives me 2.5" of down travel, 6.1" up travel.

Looking at the numbers, I figure I really cant make a decision on shock lengths until I can make full droop measurements. Then I can buy the appropriate bump stops to keep the shocks from fully compressing.

Should I worry about up travel? I mean these are pretty stiff lift springs. I cant imagine them compressing much, even w/ a high speed bump/jump. Should I just pick a shock that puts ride height right in the middle of the travel range? Thoughts?

[AwesomeJ10]

I've been reading all about shocks lately. Especially Fox 2.0's. I've basically come to the conclusion that there is no right or wrong answer. It all depends on how you want to use it? What do you want out of it? If you plan to do any high speed 'wheeling, then you will need more compression than droop.

[RamJetFSJ]

Well, I answered half my question myself last night. I drooped the front out to full extension and have a whopping 2" of down travel on the front. So that make picking shocks much easier. (looks like the 11" travel shock will be fine). I figure the back is going to be pretty close to the same, but picking a perfect shock will be a little harder due to how short the shock will be w/ the stock mounts.

Mostly I want something that will travel round fireroads at medium speed semi comfortably, and with some control. I have a few off road only toys (desert buggy, UTVs) that are very capable offroad at speed, and utilize Fox and King shocks, and they are great, but overkill and not ideal for this build.

[pcoplin]

You should really go flex it out without shocks. See where you want your tires when they are stuffed, measure where you want your bump stop to be. Then you can measure how much actual uptravel you may get.

When you flex the Jeep it'll also push down the other side more than the weight of the axle alone will.

[tgreese]

The conventional wisdom says not to allow the shocks to compress fully. If you have to extend the length, you'll likely need to space the frame bumpers down to prevent full compression... or raise the top shock mounts higher so you can use a longer shock.

Measure the distance between both shock pins and subtract the distance between the axle and the fully compressed frame bumper. This is your maximum collapsed length. Somewhat less than twice that is the maximum extended length of the shocks.

[RamJetFSJ]

Definitely wish I could ramp it to see where Im at, but with not front drive shaft, no shocks, very unsafe old bias ply tires, I just don't think Ill be able to drive around trying to find a place to do so safely. So im going to go w/ my best guess this time around and hope for the best.

Yes, I agree, you don't want the shocks to fully compress, but I have gone far enough from stock that I will just have to get the most possible travel out of a shock, and then move the bump stop down to match.

Heres my measurements so far.
Front: 24.25" @ ride height. 26.25" @ full droop. Approx. 8" of up-travel to stock bump-stop.
Planning on using the 11" shock, which will give me 3.75" of shock down travel (which will allow for the axle to be pushed down more by the flex), and 7.25" of up travel. I will get a longer bum-pstop to compensate.

Back: 20" @ ride height. 23.5" @ full droop. This one I have two options...
A. 9.24" shock. 4.35" down, 4.9" up. This will allow full droop, but will limit up travel.
B. 8.6" shock. 2.5" down, 6" up. This will limit down travel, but will not limit up travel as much.
Total travel will be almost exactly the same. Just in a different place. Again, Ill have to build a bump-stop extension to match.

Dont know which is best for the back. Really wish I could get a longer shock in there, but its just not going to happen in this iteration.

[RamJetFSJ]

So just to sum up this thread, I am swapping out the 2" rear blocks for a 1" zero rate add a leaf (steel block that bolts to the spring pack), and went with the 8.6" travel shocks in back, and the 11" travel shocks in front. Ill let you know how it works if I ever get this thing in the dirt.