Inside front wheel lifting in turn

[patrick j slatteryParticipant]

In the middle of the turn, the inside wheel, is bouncing up and down.  Any suggestions on what is causing this?  Arrow x3 kart, Jr. Yamaha class

 

[Tim KoyenParticipant]

I would say that too soft of a rear axle (or rear setup) is causing the cycling.

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[TJ KoyenModerator]

Inside front wheel can only lift if you have oversteer and are countersteering. Or the kart’s bent.

As my dad noted, probably too soft in the rear. You have too much rear lift, that’s lifting too harshly, causing the kart to break free and needs countersteer to keep it in check.

Take front grip out by narrowing the front, removing caster, softening the torsion bar or stiffen the rear slightly to keep it from bouncing and lifting too quickly. Wider rear track might also help.

Driver/Coach/Wrench : Innovative Performance/Exprit
Owner : Oktane Visual - www.oktanevisual.com
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[patrick j slatteryParticipant]

That makes sense TJ, I have a standard medium axle and middle ride height in rear and 54 1/2 in the rear.

The front has a stiff torsion bar, all out wide with long hubs in front and max caster top and bottom pills.  My driver keeps complaining of the kart pushing, so I keep trying to stop that by the move I have in the front, but now all I get is the kart is tight

pat

[TJ KoyenModerator]

If your kart is actually pushing with max caster, full front width, and stiff front bar, you either have a bent kart, the seat is in the wrong place, your driver isn’t feeling what the kart is doing correctly, or your driver needs to slow down his/her entry points.

If the kart is oversteering and lifting the inside front, it for sure isn’t “tight”.

Driver/Coach/Wrench : Innovative Performance/Exprit
Owner : Oktane Visual - www.oktanevisual.com
www.facebook.com/oktanevisual
www.instagram.com/oktanevisual

[Tim KoyenParticipant]

Sometimes being so “over the top” on the front setup, like you have now, can cause the kart to push.   I’d agree with TJ though, the kart probably isn’t pushing, or it could be pushing initially, then snapping loose and causing the driver to counter steer, which is the only logical way the inside front tire can lift.

Your front end setup is what I would call Max Front Grip.  Obviously the balance between the front and the rear of the kart isn’t there right now.  Go back to more of a baseline setup in the front and re-evaluate the setup.  Maybe a seat position change is necessary.  Is the inside rear tire lifting quickly or dropping quickly?…or even lifting at all?  How much wheel input is necessary to induce lift?

You kinda need to evaluate these things in terms of sequence.  Whats happening and when?

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DeepSeat Kart Seats
877-777-8020
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Don't bother PMing me, it doesn't work. Email is best: tim@kartlift.com.

[patrick j slatteryParticipant]

Based on a following kart video, which is the only way I was aware that the inside front was lifting, I observed the rear lift briefly and than set down quickly.  This is early in the turn, than the front inside will life 6 inches and than go back down and sometimes go back up again.  After that occasionally the out side rear might slip out after the inside front lifts up and goes back down.  I had the kart on a plate to check for bends, etc. and it was pretty good, had a slight twist in the front but was easily pulled back to center.

 

Thanks

 

[TJ KoyenModerator]

So you have so much front grip, that it is very harshly lifting the inside rear on turn-in, resulting in the outside rear being heavily loaded very quickly, causing it to break traction and go super free mid-corner. Hence the oversteer and inside front lift.

All signs point to taking grip out of the front.

Driver/Coach/Wrench : Innovative Performance/Exprit
Owner : Oktane Visual - www.oktanevisual.com
www.facebook.com/oktanevisual
www.instagram.com/oktanevisual

[patrick hubbellParticipant]

I had an Arrowax6 that would lift the inside front exiting certain corners.  Nothing wrong with it.   Best handling kart I ever drove.

[FREDDY SANDOVALParticipant]

Patrick

Check for fatigue cracks on the frame, all over, seat uprights, seat struts, frame rails, cassette brackets, spindle yokes, etc. Just to be safe.

A hairline crack under front frame rails could drive one crazy like this. Just a thought, please let us know. Fast Freddy.

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