Rear End Setup
The rear end of a kart begins from the back of the seat with adjustments including wheel hub length, track, rear ride height, axle stiffness, and seat struts. Changes to these settings are usually made when handling problems occur on the exit of the corner.
Rear Track Width
For racing, most rules dictate a maximum rear track of 1400 milimeters, that’s why our chassis are designed for rules allowing a 1400 milimeters rear track. Therefore, it is important to set your kart’s rear track to the maximum of 1400 milimeters. It becomes necessary to narrow the track when the rear of the kart is tight at the exit of the corner and has too much rear end bite. However, this is an adjustment only made when you have first changed your wheel hub length to the shortest hub available and are still tight at the exit of the corner.
Wheel Hub Length
WildKart makes four different wheel hub lengths for our chassis (75 mm, 95 mm, 105 mm and 125 mm). It’s highly recommended that you purchase all four of these sizes as they are the most commonly adjusted setting on the kart. The longer the hub the more rear end bite. Use the shortest hub if the kart feels tight at the exit of the corner and use the longest hub when the kart feels loose at the exit of the corner.
Rear Ride Height
The height adjustment of the track changes the position of the kart’s balance point and gives the chassis a certain stability. The lower the kart is at the front the more direct the chassis will be, while losing, however, on efficiency after the angular point. The lower the chassis is at the rear the more steady it will be in the curve. On most WildKart chassis there are two setting for the rear ride height. The factory recommends running the chassis with avhigher ride height for better grip. The higher ride height, like the front end, creates more leverage in which to transfer the cornering loads to the opposing tire and thus results in more grip. Lowering the rear ride height will have the opposite effect and cause the kart to be extremely loose. Only in extreme cases should you change the rear ride height.
WildKart makes three types of axles; soft, medium and hard. In almost all cases you will use the type medium hard axle. The soft rear axle is a little softer and is used when more grip is necessary on the track. This axle makes the the chassis run freely. Such cases in which you may need to use the soft axle are cold weather, slippery track conditions, and when using harder compound tires.
On a WildKart chassis, the factory recommends running two seat struts on both sides of the seat running from the very top of the seat to the two outer bearing cassetes. On the motor side it may only be possible to use one strut. The seat struts allow the high leverage point of the driver to be used to transfer load to the rear tires and thus create more rear end bite. When the extra seat struts are removed, the drivers high position on the kart is not taken advantage of and minimal load is transferred to the rear tires. As a result, the kart becomes extremely loose. The seat struts are therefore only removed when all else fails to loosen up the rear of the kart. If you do have to remove seat struts, try removing one set at a time.