There is no correct answer on low/high cross discussions. There are simply way to many variables or moving parts that play huge rolls on either side of the numbers. It all starts with the chassis, is it stiff or does it flex. A stiff chassis from the start has already increased right side wheel loads versus a chassis that you may say, gives up or flexes. Honestly, there is not a right or wrong question or answer. Most all karters say tires, tires, tires... Do you know what tires are and why teams think they need to bring multiple sets every race? Tires are load cells and the multiple sets brought are basically different rates of springs for adjusting how much load is needed for current track conditions. You could buy a $20 set of wrenches to take in place of the multiple sets of tires and accomplish the same results. Mechanical load and chemical load have a lot in common with low and high cross. All 4 get the same results, just in a opposite way.
Higher or lower cross???
- Thread starter T-roy
- Start date
XXX#40
2A supporter
lol what a load alright
Bob Evans
Administrator
Using a low cross setup, when your pushing you jack weight on the LF to make it work more, which lowers cross.
When your loose, you jack weight on the LR, which increases cross.
Like Mike said, somewhere around 54-56% is kind of a no-mans land, more or less the separation point between low cross and high cross setups.
My .02
Draw an x on a piece of paper.
The ends of each leg represent each tire.
A low cross setup will have most of the static weight sitting on the LF to RR leg.
A high cross setup will have most of the static weight sitting on the LF to RF leg.
It is sometimes easier to envision weight transfer crossing to the right by thinking of the cross load line as the pivot.
As previously stated, it is easier to add grip to a tire by adding weight to that tire. It is also easier to control that weight.
Don't take this as exactly what is happening all the way around the track, just as a method to help grasp the differences.
The ends of each leg represent each tire.
A low cross setup will have most of the static weight sitting on the LF to RR leg.
A high cross setup will have most of the static weight sitting on the LF to RF leg.
It is sometimes easier to envision weight transfer crossing to the right by thinking of the cross load line as the pivot.
As previously stated, it is easier to add grip to a tire by adding weight to that tire. It is also easier to control that weight.
Don't take this as exactly what is happening all the way around the track, just as a method to help grasp the differences.
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paulkish
old fart
"Every kart has a magic cross number usually around 54-56%. If you are below that, less cross will loosen you up. If you are above that % adding cross will loosen you up. Low cross set ups are sometimes faster, but take several laps to fire off. High cross setup s fire off faster but fade with long runs."
Wow am I having a hard time putting those two together because of the different references.
I think their saying the same thing but just don't know not being able to blend them in my head, you all are hurting my head ! ...
paulkish
old fart
No sorry needed, as I walk out for a medicinal coffee royal, I figure both statements quoted are correct saying the same thing from two different perspectives, But my poor head has yet to put them together in a way it works for me.
I have no doubt both are correct and just need to finish pushing the thoughts into each ear. ...
fastbraden11
Last of the originals
finally a correct answer,,good reply bumpy
alvin l nunley
Site Supporter
In my experience, Sprint racing mostly, being on Bob's 4 cycles, push can be caused by several things. A basic equation to consider; too much rear bite = push, too much front bite = loose. The solution to curing either one?
Push? More front bite or less rear bite.
Loose? More rear bite or less front bite.
There are so many solutions to this simple problem, books have been written about it.
In Sprint racing, if either one is occurring, the simplest solution is moving the driver position forward/backward. Push; move driver position forward. Narrow the front tread width
Loose; move driver position backwards. Narrow the rear tread with.
With an oval kart, the options become much more complicated. Stagger has to be right for the turn radius, or, a compromise between the right stagger for the turn radius and the length of the straight. You can calculate the stagger for any turn radius but if you have a tight radius turn and a long straight, a compromise might have to be found. In my opinion, changing the stagger, once the correct stagger is found, is only a Band-Aid and should be avoided if possible.
Push? More front bite or less rear bite.
Loose? More rear bite or less front bite.
There are so many solutions to this simple problem, books have been written about it.
In Sprint racing, if either one is occurring, the simplest solution is moving the driver position forward/backward. Push; move driver position forward. Narrow the front tread width
Loose; move driver position backwards. Narrow the rear tread with.
With an oval kart, the options become much more complicated. Stagger has to be right for the turn radius, or, a compromise between the right stagger for the turn radius and the length of the straight. You can calculate the stagger for any turn radius but if you have a tight radius turn and a long straight, a compromise might have to be found. In my opinion, changing the stagger, once the correct stagger is found, is only a Band-Aid and should be avoided if possible.
paulkish
old fart
Like except for the last two sentences which in my opinion are only not correct because they do not take into consideration how you intend to use the additional abilities of a LTO chassis. An LTO chassis can be setup to use more RR tire, more LR tire or use left and right tires equally in turns AND on straights. That is not the case with a kart chassis which must turn right and left. With a lefty righty chassis you setup for both tires to work when going straight because it's the only way you can equally reduce the use of each rear tire depending on which direction your turning. With a LTO chassis going straight you may be either primararly on the LR tire, the RR tire or both equally, all depending on need.
IMHO Good Post Al.
IMHO Good Post Al.