![kart cross weight kart cross weight](https://i.pinimg.com/736x/26/42/49/264249df7d91f2b1cce6b8e73c3d3515.jpg)
Moving the wheels in will raise the angle and increase the jacking effect. This is usually accomplished by sliding the wheel hubs in and out on the axle.
#Kart cross weight Patch#
So alternatively, moving the tire contact patch is relatively easy. While moving the CG is difficult, we are really only concerned with the angle between the CG and the tire contact patch.
![kart cross weight kart cross weight](https://grandauto.racing/wp-content/uploads/2020/04/Kart-cross-g-speed-Photo.jpg)
This usually requires redrilling and moving the seat or ballast. While motorcycles will lean to achieve this ideal center of gravity location, moving the CG of a kart is often not so easy. This repeating cycle is one of the main causes of hopping that kart racers sometimes experience. Now flat against the ground again, the outside tire regains grip and the kart starts to lift again. This loss of grip causes the inside rear to come crashing back down. As the kart starts to lift excessively, the outside tire's contact patch is no longer flat against the ground and so quickly loses grip. The very tight steering needed for a hairpin might cause the inside rear tire to lift off the ground too high. Even the difference between high and low speed corners can cause issues because of the steering geometry effects on the amount of jacking. What this means is that a kart that unloads the inside rear properly when grip is high might not when grip is low. Too much or too little jacking can cause handling problems, but unfortunately as we learned from the motorcycle example, as cornering force increases, the needed angle increases as well. The location of the outside tire in relation to the CG must be set correctly to properly jack the inside rear tire. On a kart however, the needed "lean" angle must be preset through chassis setup. Unlike a car that experiences load transfer across the rear tires, the constant grip potential of the kart's outside rear tire once it unloads in a corner is why it is like a motorcycle. As we've learned about when discussing tire load sensitivity, since there is no lateral load transfer, there is also no change in potential grip. An important key to understand here is that regardless of lean angle, the load on the rear tire, and therefore grip potential, is basically constant in pure cornering.
![kart cross weight kart cross weight](http://3.bp.blogspot.com/-V41Bo_ZVU4I/UCGIJ02jxgI/AAAAAAAABpk/ySSlRS6kmok/s1600/02formulacrossatvbuggy.jpg)
Expert level riders can achieve seemingly impossible angles of lean due to the amount of grip possible with modern race tires. It must lean more, because as the lateral force increases, the center of gravity must change angle in relation to the contact patch- otherwise the rider will highside and tip over. Why does this matter? Well, what happens when a motorcycle corners faster. Karts however, have basically flat profile tires and cannot lean. Motorcycle riders have a pretty good advantage in this sense as they can lean to the angle necessary to maintain balance and their tires have a rounded profile. These pictures depict how the CG of both kart and motorcycle will act through the rear tire during a corner. If you remember from part 1 how the rear of a kart corners on only the outside tire you might be able to figure out what we mean here.