Weird Hop/Rebound When Kart is under Load

Hi there,
So I am having an issue with my kart hopping when under high load, for example a banked corner or when trail braking, skipping along and losing speed and valuable braking time. I run an Italkart Laguna Black SE and this happened at PSGKA In Spanaway Washington, The Kart rides perfect in the wet with the current setup but then has the Hopping issue when dry. I don’t currently run the stiffener bar, although i think that may be the reason why. Any Ideas? Tire Pressures were 15 PSI all round when cold (21 C).

Forgot to mention, while bouncing back the kart slides initially but then regains grip and repeats the process

Giving us the full setup would help, but I suspect that if you’re great in the wet and hopping dry, you’ve got too much overall “grip”.

Probably over transferring. :man_shrugging:t2:

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So i assume it has something to do with my overall driving then? Also front camber is at -5mm and Toe is 4mm Out according to my snipers

Agree with Burpo. If the kart is good in the rain or low grip but starts hopping when it’s dry and grippy, you’re jacking too much weight or transferring the weight too quickly. The kart loads up, exceeds the tire’s limit, slips, grips, and repeats. If the axle is too soft this can exacerbate this as the axle flexes and rebounds.

Step one would be to see if it can be fixed by smoothing your driving out. Make sure you’re not too choppy on your inputs.

If that isn’t the issue, you need to remove some weight jacking. So narrowing the front end, removing caster, or widening the rear end would be the first adjustments to make. If you max out those adjustments or start to get too far away from your baseline it might be time for an axle change. Generally you would want to go stiffer to eliminate some flex and rebound, so a good test would be to tighten the third axle bearing. This will stiffen the axle up and serves as a good quick/easy indicator to see if that is indeed the issue.

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If I understand your original post, I would try a front bar. Start with soft and see what happens.

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I’ll echo the sentiments of too much transfer. I would reduce caster, narrow the front width to start.

What tire are you on? 15psi seems high.

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LeCont Reds, with light wear

Iirc we ran those more like 10-12 lbs in NJ

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I forgot to mention as well i am running full spacers out front and a soft axle which might explain some of it as well. And i believe i could widen the rear a little more if needed.

Sounds like you’ve identified the stand-out variable that might be out-of-line with a more baseline setup. I would start by narrowing the front then.

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Yep, the rear will “lift and dump” very fast with the front at full track width. Good in the wet, can cause issues in the dry…

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