All of the tires are receiving equal torque. @jjvw 's has more torque (and more power overall) than the other one. So this theory doesn't apply here.
Dave Kishpaugh's (Jeep West) geometry correction brackets are now available
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That's actually not how it works at all. The hop is caused by how effectively the power is being transferred to the ground, and that is almost entirely controlled by the geometry. With an anti-squat higher then 100%, that means that as power is applied the suspension lifts the rear of the rig. It then tends to lift it beyond a point of equilibrium, and then it comes back down and starts all over again. This happens even on flat ground, but it is exacerbated on a climb. The higher the anti-squat, the worse the bounce. As we have seen from the calculators earlier in the thread, the anti-squat % is higher on the bracket relocation relative to the mid-arm. That is why the bracket approach bounces more. The anti-squat on the mid-arm is better, but still likely above 100%. That is why JJ's does better, but still bounces just a bit.
To your point on traction, is does change, but it is a consequence of the bounce, not the cause.
But...l've been wrong before...
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In college we built a four wheel drive pulling tractor. During one of the pulls we experienced significant hop that we never saw on our home track.
We had the thing all wired with gauges for testing.
Turns out we hit the harmonic frequency of the track.
Anything could make that difference.
I am not saying this is correct, just that it could be something other than anti-squat and the geometry causing those jeeps to hop.
All four tires should be receiving equal torque (or within tolerances); however, the rear wheels will be applying more force to the ground due to more weight applied to the rear wheel during the climb. This high force causes the tires to lose traction as it is higher than the surface friction and then since the jeep has momentum going fwd (and also is slightly being pulled by front wheels) it regains traction and hops. Not both jeeps have the same torque, but the force being applied at the rear wheels is greater than what the surface/tire combination can handle. you all need stickies
All four tires should be receiving equal torque (or within tolerances); however, the rear wheels will be applying more force to the ground due to more weight applied to the rear wheel during the climb. This high force causes the tires to lose traction as it is higher than the surface friction and then since the jeep has momentum going fwd (and also is slightly being pulled by front wheels) it regains traction and hops. Not both jeeps have the same torque, but the force being applied at the rear wheels is greater than what the surface/tire combination can handle. you all need stickies
Also, any deflection in the suspension can cause the loss of traction and as it deflects back it gains traction resulting in the hop.
I am not saying this is happening with these jeeps but I have seen cars on launch wheel hop and after the control arm rubber bushings are replaced with stiffer poly bushings the wheel hop is eliminated because the deflection is reduced. Same exact geometry (same Anti-Squat), same exact car, same launch control, just the deflection was eliminated.
I am not saying that Anti-Squat is not real and shouldn't be a consideration, I am just saying that it is not the only reason for wheel hop.
I am not saying this is happening with these jeeps but I have seen cars on launch wheel hop and after the control arm rubber bushings are replaced with stiffer poly bushings the wheel hop is eliminated because the deflection is reduced. Same exact geometry (same Anti-Squat), same exact car, same launch control, just the deflection was eliminated.
I am not saying that Anti-Squat is not real and shouldn't be a consideration, I am just saying that it is not the only reason for wheel hop.
I mean the theory that the AS is the culprit here lolI think that antisquat isn't a theory.
I'm not there. It sure looks like a lot of the hop from geometry that I've seen before. Plus, my shocks have a flutter stack, meaning there is a short soft zone on either side of the immediate piston travel.
Thanks. I agree with you and don't think you are wrong.
The first jeep which hops at the bottom and then 3/4 of the way up definitely looks like geometry and High Anti-Squat.
But just thinking outside of this box to keep some actual discussion going, does this lift of the body due to high antisquat not settle as acceleration is reduced and eventually become a non-issue at constant speed. So JJ has like a half a hop at the very bottom which is due to geometry as he is accelerating, but when JJ is 3/4 of the way up the hill, is he still accelerating or is he applying a constant and hopefully smooth power to the rear wheels? If so, the bump on the hill trips the wheels causing the loss of traction and then the regain of traction causes the hop. Either way, the lower AS, the smoother/consistent power application, or the shocks quickly dampening the lift/unload, definitely resulted in a cleaner climb.
You went wheeling with @jjvw . What did you think about how your Jeep performed vs how his did? Are you happy with yours?
Are you saying your TJ hope less due the shock continue force down by lock position?
Brianj5600
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I bought these at a circle track swap meet. I'm thinking of using these to allow the upper axle mount to move in small increments. It would give me 5 positions and 1" of movement for the UCA. They are very thick and would be fully welded. Slotting the UCA axle mounts would be a pain though X4.
Do you run a flutterstack on your rebound side too? At those shaft speeds I'd be inclined to think the amount of bleed in your setup would have more of an effect than your flutter stack in the video, unless maybe it's super light. Do you know what valving you're running?
That video was the only instance where the Jeep behaved undesirabley. We also did pretty easy trails for the most part. I still need more seat time to get a whole picture. But my question was a specific one. Whether the difference in AS numbers I posted seem like the likely culprit of the wheel hop on that specific climb.
Interesting, haven't heard of anyone trying that before, now I'm really curious what his valving is
I did not review your numbers to see if they are accurate, but differences in geometry is definitely what you're seeing in those two videos. You can not tune out the front lifting like that with shock tuning. I've gone on "LJ hills" in my TJ and buggy hills in my LJ and I've never peed my pants like I would watching your Jeep climb.
That really made you pee yourself? I think that specific climb brought the worst out of it. I took it wheeling on a very difficult trail earlier this week with some big ass climbs and it never hopped. It did awesome. That being said it definitely still has a geometry problem when it comes to a climb of that magnitude and I don’t like that. I’m hoping some modifications will bring AS down enough to give a smoother climb next time
That hop was from driving over the ridge in the rock. It is in the video. What I am suggesting is that mine still did not hop despite the shocks allowing for a very short section of light damping. The lack of hop on mine is because of the geometry. The existence of hop on the other is a result of the geometry.
Shocks had very little to with why one hopped and the other didn't.
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