Explain freeing up a kart

[Kyle Casper]

What I'am wondering is what the kart is actually doing when you free it up. Are we just removing traction? Are we lifting the inside wheel? Is the frame just flexing more. Combination of things.

Thanks

KC

[Todd Godwin]

IMO, freeing a kart is often related to reducing rolling resistance (either straightline or slip angle induced).

[Patrick Hubbell]

quote:

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Originally posted by Kyle Casper:
What I'am wondering is what the kart is actually doing when you free it up. Are we just removing traction? Are we lifting the inside wheel? Is the frame just flexing more. Combination of things.

Thanks

KC

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Reduced traction/grip. Caster has a big affect on the chassis. To much will "bind" a kart. Axles(rear) and hubs would be next in the grip level. Things like tire pressure, torsion bars, track/tread width,4th rail & pinch bolt and seat struts are the finer tuning elements.

The insde rear wheel must always lift or at least unweight in order to make a kart turn. If the inside rear does not lift the front will understeer or push.

[Robby Mott]

Freeing up a kart has to do with the ability to get maximum grip from your chassis without binding it up. The chassis can bind up from too much grip caused by many different things. In my opinion, the main reason a chassis will bind up is if the inside rear does not lift. This will cause the kart to understeer and scrub speed.

My suggestion is that you go to track and find a consistent, solid baseline. Pick a turn that applies best. Get used to looking at your RPM at track out every lap. Get used to the feel and sound/tone of your engine as you try different lines or setups. If you can get out of the turn a few hundred RPM better, your lap times will reflect it. Experiment with different chassis adjustments to get the best possible exit speed....

Hope this helps!!

Robby Mott

[Paul Kish]

Hi Kyle

"Are we just removing traction? Are we lifting the inside wheel? Is the frame just flexing more. Combination of things."

The answer is that it as you suspected is a combination of things.

The kart has four wheels and those four wheels have to roll freely or the kart will bind. Practically speeking the kart is always binding and it is all a matter of degree. Good chassis tuners will be able to setup with less bind and poorer tuners will end up with more bind. Tires, chassis flex attributes, caster, camber, kpi, ackerman, driving style, vcg, etc., etc., etc., all play a part. Your job is to recognize the root cause of the most prominate binding and minimize it. Simply put, any two tires that are in conflict with each other are going to bind. Even more simply put any tire that ain't going the same direction that the kart is going will contribute to kart bind. You can have the two front tired trying to go different directions from each other. In addition to trying to go different directions from each other they may not even be heading the same direction that the kart is going. A loaded inside rear may be trying to drive the kart straight when the fronts are trying to turn the kart. The list goes on and on. Observe, study and learn to recognize the conflicts between the tires and in time it will start to become obvious what to do to reduce the conflict or bind. I don't know how many is in your crew but to really see and gather information on what the kart is doing at any given point on the track you need three observers. The first observer, by feel and seat experience is the driver who should always be the final decision maker. The second person or observation that needs to be made is "what is the kart doing". The third person or observation that needs to be made is "what is the driver doing". Gather information thru listening to the driver, watch the kart and driver on the track, discuss what is happening in terms of "tire conflict" and you will be amazed how problems will show themselves to you.