All right AnnDee, now you got me thinking. Every other vehicle like a Ford ranger or my rzr , the shock travels less than the actual tire. On my razor it has 16 inches front travel and 18 inches rear wheel travel. The front shock is an 8 inch stroke and the rear shock is a 12 inch stroke. So the rear is a 1.5 motion ratio. 1.5 wheel travel equals 1 inch of shock travel. 12 inch shock gives you 18 inches of travel.
I just put my tape measure on the rear Jeep frame and it’s 5.75 inches to the bump stop pad. And I marked the shock. I’m going to jack up the frame and see what it does.
Yeah, it was a surprise to me too when I first realized that. I was used to double A-arm and McPherson struts where the shock and spring move less than the wheel, but a live/solid axle is a little different.
@Glamisfan thanks for actually checking, it doesn’t look like the real world results are as extreme as my calculations.
I'm still gonna be researching and the next time I do my rotation I'm gonna mess around with the rear axle and see if the springs start wanting to pop off. When I did the swap to rubi springs I didn't really think of it, but I don't recall dropping the axle too far to even install the springs.
There are a couple measurement you can do before you make a selection.
Shock length at rest center to center.
To get more shock travel the shocks get longer. So you can't just pick one with more travel. If it's not centered at rest you will be limited on one side of the travel. Find one that centers up for your length and see how much travel you can get.
Distance between bump stops F/R.
The upper factory bump stop compresses, not sure how much unfortunately. At stock you will have like 4.5" of travel in the front and 6" of travel in the rear, plus compression. This will limit the spring compression and ultimately the shock compression, giving you the total travel. You can add some lower bump stops if you need to limit the travel too.
I have done a ton of research on this and found that the guys at Accutune in CA are awesome to work with. They have a set-up sheet if you really want to dig into the details, plus they can valve the shocks for your liking if you don't go for adjustable shocks.