LCoG and long arm lifts

I am curious where the 20/80 split trend came from. Is it that they cannot fit more up because they are trying to stay low? Is it because that is their desired ratio? I’ve heard some mention that uptravel is not important for rock crawling specifically, but I have had many instances where I am balanced on a few boulders and the tires are stuffed way up in the wheel well. Without that uptravel, the body would undoubtedly have leaned over more. The 50/50 split is undoubtedly better for a well balanced multi task rig because it also unlocks go fast ability. But I would argue that I use uptravel a lot even while slow crawling.

I think it comes from several different avenues. One is the Moon Buggies, they are low slung (as low as a 40 inch tire lets you) with very low AS and very high unsprung weight. They want stabilty at all cost and with the high unsprung weight they are not worried about the chassis being upset by the shock bottoming out.

Of course you have the LCOG crowd and I think in a way they looked at Moon Buggies and other vehicles from other sports and saw that a low center of gravity is good for them it has to be good for everyone. The problem is that pesky thing called packaging and especially with a TJ running 35s with 2 inches of lift how do you get any up travel to deal with the higher unsprung weight of the bigger tires? It was such a thing for a while the RE actually made a version of their long arm with only like 2-2.5 inches of lift and had to use rear radius arms to make it work.

And you got those out there that think that if 10-12 inch coilovers are good, then 14-16 inch are better but then how do you mount them and get the right up travel? Do you make the thing taller? Do you move things out of the way and make things fit? Or do you be lazy and say F it I do not need a good shock bias and hope I can tune them to work.
In case anyone is wondering after Brian's comment - I'm at 6 up / 8 down. What's that, 43/57?

And that is one advantage of running longer shock when you can. I doubt you would really notice a difference of an extra inch of up travel for what you use it for and how much work to actually get to 50/50?
As with anything else, shock splits are nothing more than tech and an understanding of how shocks work in relation to the rest of the rig. Several things can be derived from a build by knowing about the shocks and how they are positioned. This is a reason why it comes up so often in the spring threads.

And understanding that most of us are not building single purpose rigs. So to be good at most things striking a balance is really the key to that.
 
It is much easier to build in a way that results in a disproportionate amount of down travel, as shown in your recent efforts to build the opposite and maintain up travel. Very few will go through the effort of moving mounts. Far fewer will go through the effort of understanding why there would be a benefit to moving them in the first place.

It's easier to bolt on a longer shock and pretend that long reach down is functionally awesome. But then you come along using your rig in a way many fantasize about where experience shows the opposite is true.

Kind of like Gen........
 
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And that is one advantage of running longer shock when you can. I doubt you would really notice a difference of an extra inch of up travel for what you use it for and how much work to actually get to 50/50?


Actually, on my rig it would be a piece of cake. Add an inch of preload to the coilovers and I’m at 7/7. No change to my bumps or limit straps, and I don’t think it would create coil bind. Perhaps a slight tweek to my caster in the dront front and pinion in the rear.

But - I like my stance, and as I said I’m happy with how it performs.

All that having been said, would there be an advantage of getting to 50/50?
 
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But - I like my stance, and as I said I’m happy with how it performs.

All that having been said, would there be an advantage of getting to 50/50?

With the weight you carry, it doesn't matter that much. No changes you are going to make to the shock bias will overcome the penalties for being that heavy.
 
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I think it comes from several different avenues. One is the Moon Buggies, they are low slung (as low as a 40 inch tire lets you) with very low AS and very high unsprung weight. They want stabilty at all cost and with the high unsprung weight they are not worried about the chassis being upset by the shock bottoming out.

Of course you have the LCOG crowd and I think in a way they looked at Moon Buggies and other vehicles from other sports and saw that a low center of gravity is good for them it has to be good for everyone. The problem is that pesky thing called packaging and especially with a TJ running 35s with 2 inches of lift how do you get any up travel to deal with the higher unsprung weight of the bigger tires? It was such a thing for a while the RE actually made a version of their long arm with only like 2-2.5 inches of lift and had to use rear radius arms to make it work.

And you got those out there that think that if 10-12 inch coilovers are good, then 14-16 inch are better but then how do you mount them and get the right up travel? Do you make the thing taller? Do you move things out of the way and make things fit? Or do you be lazy and say F it I do not need a good shock bias and hope I can tune them to work.


And that is one advantage of running longer shock when you can. I doubt you would really notice a difference of an extra inch of up travel for what you use it for and how much work to actually get to 50/50?


And understanding that most of us are not building single purpose rigs. So to be good at most things striking a balance is really the key to that.

I'm not sure where it comes from. All I know is as long as I've been seeing pics of builds on the internet, I've been seeing shocks with very little uptravel and worse, almost meeting in the middle on a rear axle to get as much down travel as possible with no other thought given to much else. But there again, I suspect a lot of that is just due to not understanding or caring about shocks well done. I also suspect that as the race tech and competition tech has become more mainstream due to how fast the information can be put on the internet, the overall knowledge about paying more attention to what shocks do has improved significantly. There has always been a group of folks doing it, now it is easier to see and take examples from than ever before.
 
But - I like my stance, and as I said I’m happy with how it performs.

All that having been said, would there be an advantage of getting to 50/50?

With the weight you carry, it doesn't matter that much. No changes you are going to make to the shock bias will overcome the penalties for being that heavy.

This.
 
No, I was right - just at a different level of precision.... :)

{ENGINEERING SNARK FILTER ON}Actually, if you're talking about precision, you should have said 40/60. Your measurements (6 and 8) have only one significant figure of precision. Therefore, the quotient should be stated to one significant digit by rounding. That makes it 40% up, not 43% up.{ENGINEERING SNARK FILTER OFF} ;)
 
I am curious where the 20/80 split trend came from. Is it that they cannot fit more up because they are trying to stay low? Is it because that is their desired ratio? I’ve heard some mention that uptravel is not important for rock crawling specifically, but I have had many instances where I am balanced on a few boulders and the tires are stuffed way up in the wheel well. Without that uptravel, the body would undoubtedly have leaned over more. The 50/50 split is undoubtedly better for a well balanced multi task rig because it also unlocks go fast ability. But I would argue that I use uptravel a lot even while slow crawling.
I don't know why, but I agree with this statement. I say "I don't know why" because I am confused with what I have actually seen on the trail. I currently have 50/50 in the rear but prior to that I just had shocks in the stock locations and my wheels would fully stuff up into the wheel well prior with the stock locations and now with the 6" up. Same thing with the front, I have not touched the front at all and I believe it has pretty short uptravel in the front. However, I see just as much of the front wheel being fully stuffed up into the wheel well as I do with the rear wheel. Commonly see fully stuffed wheel and extended fully on the other side prior to and currently. I honestly just outboarded my shocks in order to get the lower shock attachments higher while maintaining up travel. I have not really seen/felt much benefit on the trail with the outboarded shocks and the 6" up travel (other than the shock lower mounts aren't hitting rocks). Perhaps it is the shocks I chose, or the fact that it sees very little road time that I have not noticed a difference.
 
NashvilleTJ's stance.

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@NashvilleTJ with your current settings what is you belly height?

About 21 at the skid. What keeps the skid there is the tranny pan on the 545RFE is low. Ironically, everything behind that - including the Atlas - is flush with the frame. One of these days I'll get around to building a new skid for it.
 
About 21 at the skid. What keeps the skid there is the tranny pan on the 545RFE is low. Ironically, everything behind that - including the Atlas - is flush with the frame. One of these days I'll get around to building a new skid for it.
That is one beautiful jeep! Looks like it's getting ready to pounce on a Prius or something.