Question about newer kart chassis handling

Today I drove a Mach1 chassis with a X30 engine. The track was extremely grippy and I had the kart rear hopping on throttle on almost every turns. We tried to free the chassis by widening the front and rear axles, adding more camber but it had almost no effect, I couldn’t adapt to the conditions and had to cope with the hopping.

I had the same issue, albeit less important, last year on a CL chassis. Are all the newer chassis like this ? I feel like we can’t have any entry rotation anymore and it is messing with my driving style.

My laptimes were good though, but my neck wasn’t strong enough to handle the hopping.

My crg kt5 had the same behavior - I tried a ton of different adjustments, seat position, ride heights, camber, adding caster, rollbars, toe settings. Rear had to be at max width - any narrower and the rear hopped even more. Only thing that took the hopping completely away was taking almost ALL the caster out - from top and bottom. This was possible after adding another sniper kit to the underside. Taking all the caster out from the top sniper didnt help

30mm frame

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Could the seat go lower?

I think it was already at the lowest possible. We could add more between the seat and the chassis to stiffen the chassis, forgot the name

Could you go to “ridiculous” extremes of tire pressure to calm the hopping down?

We went up from 0.75 bar to 0.8 bar on the rear (10.87 psi to 11.6 psi), which mitigated a bit the issue but the core issue was still there

What size tubing is the Mach 1? And what size are you?

Lower the rear ride height, lower the seat, stiffen the axle, take caster out etc…

Karts have definitely gotten more flexible the past several years.

30/30mm. Mechanics told me chassis were getting stiffer and stiffer, with a lot more grip on rear and they were struggling to free them

190lbs 5’11

Maybe they are trying to go stiffer again. I know I have compared the 2006-2009 spec Merlins to todays and the difference is huge how much stiffer the karts used to be.

You’re on the bigger size for a 30/30 but it should be workable, just might take a bit more effort to find that sweet spot. Sounds like you were taking good steps to adjust it.

I had less issues with the CL chassis from 2021 to be fair. I would like to try an OTK now

Do it. The kosmic I drove felt great.

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OTKs just go fast out of the box.

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That seems to be a narrow window in tire pressures, whereas your other tuning elements were taken to more extremes (track widths, caster, etc).

Do something crazy that doesn’t cost anything but your time. Crank up the rear tire pressure until you get way loose.

I’m not a karting expert, but I like to experiment with tuning and data gathering. I did say “ridiculous”, lol…