Chassis Set Up Volume 1

Sorry it's been so long since my last post but it has been a little crazy around here in the past few weeks but I will try to keep the posts coming (Hopefully somebody is reading this, otherwise it's kinda like talking to yourself ;) ) in a more timely manner.

Today I have decided to start a multi part series that will cover various Chassis setup changes and how they react. I think the best place to start is to explain the axle and it's components.

Because a Go-Kart Chassis does not have a suspension like a car and uses the torsional characteristics of the frame itself as a suspension the axle becomes a very important part of the equation that makes a go-kart function.

First off let me explain the most important thing that you need to know, because a Go-Kart has a solid or live rear axle it is very important that during cornering both rear wheels are not on the ground at the same time. Everybody needs to understand that the majority of street cars on the road today have what is called a differential in the rear end, this component allows the inside tire during cornering to spin slower then the outside tire which has to cover more distance to get to the same point.

In Go-Kart racing we don't have the luxury of a differential so in order to prevent tire scrubbing (commonly known as a tight condition) it is important to unload the inside tire during cornering. Axle stiffness plays a crucial part of accomplishing this task because it allows you to adjust the grip that the rear of the kart produces.

The stiffer the axle the harder the weight transfer of the chassis forces the tire into the ground which increases the grip at the tire, conversely when you run a softer axle the weight transfer of the chassis is deflected through the flex of the axle therefor putting less pressure on the tire decreasing the tires grip.

A good way to test and find out which direction that you need to go is by using different length rear hubs or by adding or subtracting axle locking collars, shorter hubs allow the axle to flex more and will decrease rear grip and a longer hub or adding an axle collar will increase the rear grip so for a quick change between practice sessions one can add or subtract a little grip and see what is faster or slower, for example if you go from medium hubs to short hubs and see an improvement in performance then you might want to try one step softer axle with the medium hubs and see what happens.

Wheels will also affect the amount of grip that you have if you use a stiff wheel like a cast aluminium wheel it will have alot more grip then a soft wheel like a spun Douglas, Magnesium wheels dissipate heat better then aluminium ones which will allow the Kart to go longer laps before overheating the tire which keeps the chassis faster longer.

Different track configurations and conditions will dictate whether a soft axle or a hard axle will be faster and only track testing and keeping good records will help you make the right decision on any given day.

I hope I have explained this so that everyone understands but if I didn't feel free to leave me a note in the comments section a and I will be happy to answer your questions in another post.

Thanks to all those reading this and I will be posting Chassis Set Up Volume 2 in the near future so keep checking.

Francis