In this section we will be explaining the information that pertains to the front end of the chassis encompassing the front spindle adjustments of caster/camber, wheel alignment, and width.
Caster is the inclination of the front kingpin by which the front wheels turn. On all vehicles there is caster inclination. On your Top Kart there is what can be called a significant amount of inclination.
This means that when you turn the steering wheel, not only are the front tires pointing left and right, they are also moving up and down. This allows the relative weights of the rear tires to be manipulated and make the turning of the chassis more efficient. Since the rear axle solidly connects both rear tires and mandates they spin at identical speeds, getting any brand of racing kart to turn is inherently very difficult.
If you don’t believe this, try putting your friend in your kart, and manually push your kart around on the ground. Going straight is significantly easier than when your friend is turning the steering wheel. Without caster, turning a kart would be next to impossible. You can use caster to influence how your Top Kart turns in to and through corners, simply by spinning the caster pills which come standard on your chassis. Typically in most situations, increasing the inclination of the front kingpins (adding caster) will provide more rear tire adhesion to the track. This is because due to the front inclination, more mechanical energy is being transferred from the front of your chassis toward the rear. This creates more twist, or torsion in the chassis tubing.
Conversely, decreasing the inclination of the front kingpins by spinning the caster pills in the opposite direction will reduce rear grip, or make the rear tires adhere less to the track surface. Most often, Top Karts prefer to start their racing weekends with more caster and end with reduced caster. Remember to take in to account the natural grip level of the track itself, tire wear, tire compound, as well as other influencing factors which impact the optimization of your Top Kart caster settings.
This is the standard Top Kart setup for wheel spacing. Start your weekend off with 20mm of spacing on the inside of the wheel hub (1 Big 10mm, 2 Small spacers 5mm).
If your chassis is Understeering going into the corner, to get to the apex you can start by widening your front end a small (5mm) wheel spacer. Increasing your front track width will allow more of the tire to be used upon steering input having you turn the wheel less on initial turn-in.
If your chassis is Oversteering going into the corner, you can start by narrowing your front end a small (5mm) wheel spacer. By decreasing your front track width you will use less of the tire upon steering input and slow the front end down upon initial turn-in.