The kart seat, a key variable of vehicle setup

THE SEAT

TKART Staff

01 February 2016

In karting, the seat’s contribution is not in the way of comfort; rather, it’s another element to work with to obtain the best set-up

WHAT IS IT?

HOW DOES IT WORK?

IN PRACTICE

In a sport in which weight is determinant and the goal is eliminating all unnecessary grams (keeping as close as possible to the minimum regulatory limit, from 145 kg in KFJ to 175 kg in KZ), the driver himself represents a sizable “piece” of the aggregate moving mass that is the kart in motion. Therefore, it’s important to know where his weight force acts and how it affects vehicle performance. In light of what we just said and of the fact that the driver’s body is necessarily supported by the seat, any decision on how to position the driver+seat cannot but be made in function of the variables that inform the quest for the best set-up.
So in karting, setting the driver seat one way or another has nothing to do with comfort; rather it has to do

with the scientific observation that whether the driver sits higher or lower off the ground or farther back rather than forward strongly conditions where the kart’s center of mass falls and therefore how close we are to obtaining the desired set-up.
Before we continue, we should point out that there are two kinds of seats: flat bottom and round bottom (see the image in the lower left corner). A flat bottom seat can be set lower to the ground, which means it allows to lower the center of mass more; but it’s more uncomfortable compared to the round kind. Of course, all seats, regardless of make and model, come in different sizes: choosing the right one for you also makes a difference on driving performance.

THE AGGREGATE POSITION OF SEAT PLUS DRIVER DETERMINES WHERE THE KART HAS ITS CENTER OF MASS - SO IT’S A KEY VARIABLE OF VEHICLE SET-UP

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Round bottom seat and flat bottom seat

WHAT IS IT?

HOW DOES IT WORK?

IN PRACTICE

SEAT POSITION

WEIGHT DISTRIBUTION

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DISTANCE

HEIGHT CHANGE

Seat position can be changed longitudinally (forward/backward) or vertically relative to the ground (high/low). Usually manufacturers provide length and height ranges you can work within when doing your set-up or set measurements that can’t be changed.
The weight distribution standard range between 55 to 60% load in the rear and 40 to 45% in the front.