Oh! I knew you were running the geo correction. I missed the UCA statement and read LCA.
Arizona Rock Crawling Daily Driver
- Thread starter starkey480
- Start date
OP
OP
Couple of crawling clips from last Thursday. Took one of the pole vaulters I coached before he leaves for the air force. Couldn’t quite get up that last waterfall. Typically I can but the rain washed the bottom out deeper and left it muddy. There’s a giant drop on the other side of it so I wasn’t really keen on giving it the skinny pedal 
OP
Thanks! Fun little day. Made me appreciate how much more difficult wheeling is for y’all that have to deal with mud. Even just a little bit robbed so much traction.Great clips!
OP
Going wheeling with my dad today! Running a familiar trail (Elvis), on the way to a new trail called Bad Medicine.
Reason I’m doing Elvis again is I lowered the axle UCA mount holes 3/4” which puts static antisquat at roughly 80% now and I want to test and experiment how it does vs last time on the big waterfall when I had it set around roughly 100%. I still had slight hopping last time though it was better.I’ve mentioned this before but my whole purpose behind doing geometry correction was to get rid of hopping which is a big issue on the trails I wheel. What I’m seeing so far is that I’m not hopeful about short arm geometry changes. The reason is, hardly any climbs out here are flat faces. You always have one side of the axle dropped down. On a short arm, 5” of droop causes a far greater change in antisquat values than a midarm would. So I can get my instant center pointed perfectly at ride height but that all goes to shit once you put the rig on a climb or introduce any kind of axle travel. Not to mention when you’re on a climb there’s less weight on the springs which raises the rear end up and changes the geometry.
That all being said I’m still going to experiment the sake of knowing how changes in geometry affect the rig and how it handles. And hopefully improve hopping as much as I can until I can get a midarm.
Reason I’m doing Elvis again is I lowered the axle UCA mount holes 3/4” which puts static antisquat at roughly 80% now and I want to test and experiment how it does vs last time on the big waterfall when I had it set around roughly 100%. I still had slight hopping last time though it was better.I’ve mentioned this before but my whole purpose behind doing geometry correction was to get rid of hopping which is a big issue on the trails I wheel. What I’m seeing so far is that I’m not hopeful about short arm geometry changes. The reason is, hardly any climbs out here are flat faces. You always have one side of the axle dropped down. On a short arm, 5” of droop causes a far greater change in antisquat values than a midarm would. So I can get my instant center pointed perfectly at ride height but that all goes to shit once you put the rig on a climb or introduce any kind of axle travel. Not to mention when you’re on a climb there’s less weight on the springs which raises the rear end up and changes the geometry.
That all being said I’m still going to experiment the sake of knowing how changes in geometry affect the rig and how it handles. And hopefully improve hopping as much as I can until I can get a midarm.
Not possible. The exact same amount of weight will be on all four springs regardless of how the rig is pointed. The distribution of that weight changes but the total never does and can't.
OP
So even though gravity is pushing straight down, and springs are no longer vertical, the springs will be compressed the same amount? I was under the impression that there would be less force compressing the springs and that some of the weight of the rig would be transferred to the links pushing up through the chassis if let’s say you’re sitting at the bottom of a waterfall with your front end on top of it and the rig is pointed vertical
OP
Well we got to the first obstacle and my dads steering box started pouring fluid out. Will look at that later. We parked his Jeep and I played on some waterfalls that weren’t far up the trail and we went home. My Jeep climbed great but I was hoping to compare it to my dads Jeep.
OP
I moved the axle UCA back up the 3/4”. It felt too loose, rolly, and squatty with it lowered. Plus decreasing the vertical separation at the axle puts more stress on the links and as a result the frame mounts. It was more of a science experiment than anything. After moving it back up the 3/4” I was blown away how much better it felt again with such a small adjustment.
Im keeping the first adjustment I made of moving the frame UCA up 3/4”. That put my static AS right around 100% again. I think if I want less in the future I will raise that mount up a little more but this may be as good as it’s going to get with short arms.
I’m also realizing I’m being too picky about hopping. The Moab climb was an excellent example of geometry related hopping and too much antisquat. But I’m seeing here in AZ that when your front is up on a ledge with very little traction and your rear tires are driving straight into a vertical wall, you can bounce off and there can be traction related hopping there as well regardless of geometry.
I’d like to go back to Moab and try that steep hill with the change I made that reduced AS by 20% and see what happens, but I can also think of some similar climbs here.
Im keeping the first adjustment I made of moving the frame UCA up 3/4”. That put my static AS right around 100% again. I think if I want less in the future I will raise that mount up a little more but this may be as good as it’s going to get with short arms.
I’m also realizing I’m being too picky about hopping. The Moab climb was an excellent example of geometry related hopping and too much antisquat. But I’m seeing here in AZ that when your front is up on a ledge with very little traction and your rear tires are driving straight into a vertical wall, you can bounce off and there can be traction related hopping there as well regardless of geometry.
I’d like to go back to Moab and try that steep hill with the change I made that reduced AS by 20% and see what happens, but I can also think of some similar climbs here.
OP
Filled in the old stock hole and welded the washer on for a little extra strength.
Cut the bottoms off my LCA mounts and boxed it in. Made sure the plate is behind the joint and above the bottom of the joint so a rock can slide from the joint onto the plate and not get hung up.
OP
I have geometry correction brackets. I’ve added some holes though
I was looking and figured you either added some length the axle brackets or did the geo correction brackets. so your final assessment is the best geometry is as follows?
LCA axle is raised 1 5/8”
LCA frame is lowered 1”
UCA axle is raised 2.5”
UCA frame is raised 3/4”
OP
That is what I have arrived at so far. That is all the Jeep west positioning except for raising the frame UCA. I did that to try and decrease the antisquat and make it hop less. I have no data to suggest that any of the configurations climb better than stock but we will see.
OP