xxxtreme22r

Haven't seen anything really posted like this. So here's another debate thread.

What do you guys feel is more important when off-roading. Droop or uptravel. IFS and SA.

I am pretty sure droop is more important when desert/prerunning. But what about your regular trial riding/crawling.

scuba

Lockers.

xxxtreme22r

lol lockers won't help in a severe off-camber condition. If anything, with a newbie to crawling etc, it might worsen the effects. He might think it's ok to drive on 3 wheels all the time.

xxxtreme22r

no no, not ifs vs SA but droop/uptravel for each. probably the same, but just throwing it out there.

camo31_10.50

i've seen stock IFS with relaxed torsions have some pretty good travel..now it's not but about 4" or 5"..lmao

lotsof LT IFS suspension (for toyota's, without going FULLY CUSTOM) yields about 10-13" i believe..and most people use 14" travel shocks for their SA lifted rigs..so that's about the same right? LMAO

Tofer

i say droop as well.

tc

Depends on the application, but IMHO, you people who say droop are smoking crack and need to explain.

With either rock crawling or high speed whoops, when you bottom out the compression travel, that area of the truck is going up - no way around it.

Rock crawling - the classic IFS scenario: you fully compress the front driver corner and the truck leans over.

High speed - you hit the whoop, bottom out and jump the truck ... tires aren't on ground, you're slowing down.

As in all things, balance is important. Obviously, getting compression travel can result in a higher ride height and COG, and that can lead to other problems with stability.

Remember, that the spring force goes down as the suspension droops - there isn't really any tractive force on that wheel that's just "hanging" there.

The only things droop travel are good for are pictures on the internet and to "catch" the truck as balance changes (if the wheel is off the ground, you free fall a ways, if the suspension is drooped out, you have the shock to control the motion a bit).

xxxtreme22r

thank you TC, this is why I posted this, as low compression (uptravel) will cause lean over. Big problem with the IFS guys. Which in a way actually takes away from your other corner's droop. If you had more up travel then the truck wont lean as much allowing you stay on a more camber ground.

I never thought about the jump scenario with the prerunners. But it makes sense.

Now if you look at some of the hardcore crawlers, alot of them dont even use springs, just a shock. I assume this gives as much uptravel as possible so the body stays more upright and level.

Mountain Cop

Subscribed

tc

Well, it's a bit more complicated than that, as there are numerous other factors, for example spring rate plays a huge role. If you have super stiff front springs and super soft rear springs, the truck is going to lean over too, because it's easier to compress the passenger side rear than the driver's side front (for example).

All vehicles have to have springs to support the weight of the vehicle. What I think you are referring to are gas shocks, that use air pressure inside the shock as the spring.

xxxtreme22r

but as you had mentioned, spring rate means nothing without the ability for the spring to travel because of a bump stop, too short of a shock etc etc.

SoCal4Running

Gonna go out on a limb here and say they are both equally important but if I had to chose one it would be droop. No reason other than I dont want to make a custom engine cage or cut my fenders to get more up travel

PismoJoe

I'm not really a rock crawler kind of guy, so I am speaking IFS

For prerunning you want sufficient droop and uptravel. It's really not a matter of either or, but a sufficient combination of both.

Have your springs to stiff (coil overs), you limit uptravel which results in a rougher ride, but would be better for strictly jumping. More like strictly HUGE jumping

But you can't build a truck that only jumps, it needs to handle different terrain such as whoops, compressing and decompressing at high rates, so you need sufficient droop as well to handle the sudden change is ground height. Again, if you have your rig set up for maximized uptravel, your suspension would be too stiff and would not have enough up travel to smoothly handle terrain such as whoops.

So you see, it's not a matter of 'either or'

Perfect example, Here's a pic of my rig. My droop travel v uptravel is virtually equal, give or take a few cm's or so. Coming up, you need sufficient uptravel to absorb an initial impact, or a change in terrain. If you do not, your rig would be set up too stiff for a scenario like this, which means a rough ride for you!


You just want to make sure that you don't have too much uptravel, which results in bottoming out. Now you can run virtually low uptravel for your primary coil overs if you are running a triple bypass secondary upfront, but that is a different topic in itself.

Here's a pic showing the droop travel needs. You need a suspension that can drooptravel about as much as it can uptravel, giving you the maximum benefits of both types of travel and allowing the truck to rebound sufficiently. Again, here you don't want too much uptravel, or you bottom out. To much drooptravel, and the rebound is not as smooth and conflicts with uptravel needs for various terrain.


BTW- my travel w/ 4WD is 14" stuffed v traveling

My droop travel setup does make a great internet pic, but it also makes for a good all around performing prerunner if its set up correctly

Sorry torsion bar guys, if you're serious about travel, you need to do a coil over conversion.

DethYota

Def subscribed. Thank you PismoJoe for the awesome explanation. I want a prerunner setup so this information is critical. Coilover Conversions are the way to go! One day!

xxxtreme22r

I agree coilovers are better for prerunning and most likely crawling. too bad no one makes a direct fit coilover for the IFS guys. only way to go is an LT setup w/ coils.

xxxtreme22r

I hope noone thinks I am an idiot for posting this, but I just got thinking about this from looking at a lot of built jeeps and how much tire clearance a lot of them have and how little up travel they would have because of it.

PismoJoe

Haha no one thinks your an idiot, it's a good topic!

Gnarly is right though, this topic varies widely on your particular set up.

IFS torsion V IFS coil overs V SAS....all three of these setups are somewhat incomparable when you break them down. Even more incomparable when you factor in what type of wheeling you plan on doing, this can change the game completely.

Volcom

Having all that low un-sprung weight down low really helps keep rockcrawlers stable in the big rocks & tough trails. You've only seen pictures of rigs with big droop rather than actually drive one on a tough trail with big rocks so your comment & opinion about droop is only good for pictures is not credible.

Here's a perfect picture to prove my point.


If he didn't have all that droop, that heavy axle, wheel and tire would be several inches to a foot high on the passenger side thus raising the COG of the rig. In this case, he might have ended up flopping on his driver's side in a huge hole. Having that droop helps him out big time.

scuba

Great explanation. Easy for a noob like myself to understand

4Crawler

iTrader: (3)

I find more droop is quite nice on in the rocks. Having a lot of extra up travel is basically just extra height, raising the COG. Some up travel is good, but too much is not, at least in the rocks, I probably have like 1/4 up and 3/4 down travel.

For high speed pre-running, up travel is good to soak up bumps without launching the truck into the air. Down travel is also important, so those guys probably run more like 50:50 up to down travel.

I've done trails like the Rubicon back when I had some generic 3.5" lift springs with marginal droop and later with more droop (with rear springs up front) and the difference is very big. Below the big drop off in the Big Sluice and the first time I went through, I did about a 3' free fall off that big rock (and that was idling along in 224:1 low range) (sorry no pix of that), and for a while I was teetering on one rear and one front tire. Below is the same spot, 4 tires on the ground the whole time and that spot was almost a non-event:



And more droop also helps keep the rig more level in a lot of situations, here is the Golden Crack at Moab (sorry I don't have pix of both rigs in exactly the same position):