tc

Been paying more attention to people's bumpstop/limit strap configurations lately, and it made me wonder - Which is more important for 'wheeling - compression or droop?

Seems to me that a long travel in compression would be better - once you hit the bumpstop, that side of the truck is going up...

(Oh - and let's keep this in the realm of rockcrawling, not high speed desert rigs)

4Crawler

iTrader: (3)

For rock crawling I find less compression travel and more droop travel works best. Any extra compression travel is just additional height that raises the center of gravity. I have a little over 4" of up travel and at least twice that in down travel on my front axle, similar in back. Downtravel is what keeps tires on the ground and the vehicle level:



Less downtravel and this is what you get:

deathrunner

Please don't attack me for having an LT kit. I set it up for a bias toward crawling. My plan was to make IFS flex as well as it could. I achieved what I wanted.

Anyway, afterwheeling with stock arms, LT arms with torsions, and LT arms with coilovers, it became apparent that compression is difficult with IFS. Droop is cheap.

Whenever I set my suspension up to have alot of compression, I only ever got to use very little. I was always maxing out droop without a problem.

I found 2 solutions, both of which I did.

1) softer spring rate to ease compression.

2) Less compression travel, so that you can actually use all the travel.

By having the suspension in the middle of the travel, or with slightly more droop, I am able to utilize all of the precious travel.

Flygtenstein

FWIW, I have almost 5 inches of front shaft showing on a 12" shock while I have a bit over 6 in the rear on a 12 thinking it is time for 14's to trade compression for trimming.

On a street driven truck, any less than 2-3" of pure vertical compression rides rough. Shocks are usually outboard of the bumpstops, so there is more articulated wheel travel.

Not enough compression, the tire stuffs and lifts the rig.

Too much and you sacrifice droop.

On leaved trucks, the bias is heavily to droop. Lots of low swapped trucks have 3" up and 9" down.

On a linked truck, hoping you can set it up "ideally" I would shoot for close to even/even.

Intrepid

I would have to say both are pretty important, as 4crawler mentioned, without droop, you lift a tire, however, in the same pic, if that guy had more available compression on the front, he wouldn't be at such an angle because his front driverside would be stuffed leaving him more level.



Not necessarily true, if you cut your fenders out you may have more room for compression without having raised the COG at all.

If I had to take one over the other, I would take downtravel, but a happy medium is best IMO.

joez

Im a big fan of lots of droop. I run 4 up, 10 down up front at the shock, and am very happy with the setup. The rear is 3 1/2 up, 8 1/2 down at the shock. My bumpstops bottom just before the shocks do, which is just where the springs flatten out. The truck rides smooth on the road, could use a little more compression when bombing arround the dunes, and wheels great in the rocks and trails.

AH64ID

I think that the front could compresss more, the weight has just shifted and not allowed the drivers side to compress more due to the lack of droop on the pass side...


I pretty much agree with 4crawler... compression should be set to the min possible for the best street and trail ride, while droop should be as much as possible..

getitdone

This is a great thread for sure. Interesting to hear the different opinions.

How's about this for a question, how do you increase downtravel in a leaf sprung vehicle. Is the only thing to replace the springs?

4Crawler

iTrader: (3)

First is to find out what is limiting down travel, could be a number of things:

Shocks too short or shock bushings binding.
- Use longer shocks and/or orient shock bolts to not bind.

Leaf spring clamps too tight.
- Loosen or modify clamps to allow leaves to move freely.

Main leaves have too little free arch.
- Swap for more highly arched leaves or re-arch leaves. I did both on my '85, using '83 pickup main leaves with more free arch and then re-arched the flatter '85 leaves to match.


Spring/shackle bushings binding.
- Use something like orbit eyes or johnny joints in the spring eyes and/or shackles

And you can always install double shackles or a buggy leaf to increase droop by letting the spring fall away from the frame.