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264 pages of book are divided into 2 parts:
Kart Handling Theoretical Basics and Kart Chassis Setup.
First part consist of these sections:
Parameters of kart frame and their influence on handling (front-end, rear axle, frame rigidity)
Kart wheels and their influence on handling (wheel breakaway, thermal processes in wheels, tires)
Force acting on kart in movement and kart handling (forces, balance, cornering, knematics and dynamics)
Second part provides information about adjustments and to make them to achieve expected results:
Frame parameter control (measurement, weight distribution, front-end adjustments, rear-end width)
Kart wheels (disk and tire selection, balancing, pressure, effects of camber and toe-in changes)
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From section Kart Movement During Cornering, Without suspension and Differential
... Thus, permanent contact between each wheel of a motor car and a track allows to turn without wheel slip
and without forces hindering a turn of this kind.
Kart is a different matter. Kinematics of its forewheels movement has no difference from that of a motor car,
therefore they will turn in a same manner as a car. However, the kart rear drive shaft is non-split and with no
differential. Therefore, kart rear wheels will tent to maintain equal angular velocities and to pass equal paths during cornering...
...And if the outer wheel passes a distance longer than that of the circumference corresponsing to its rolling, it means the wheel
is to be "dragged" at a certain distance...
...All this occurs in the kart chassis due to absence of a differential. Such phenomenon is known in science as power circulation.
It is true that to "drag" a wheel, certain work is to be done. Additional work is also performed at wheel skidding. If these works
are done at the same time and are wasted onto themselves, then power is used onto itself - circulates. Since friction takes place
at the same time, both for braking and skidding, this power is wasted uselessly...
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Above all, both these forces of skidding and braking are equal. Each force is an interresponse to another. They "cause" each other.
Together they create a couple of forces that tend to turn the whole kart to the side opposite to the steering wheel rotation
(Figure 5). In this case, the less the turning radius, the bigger is a moment of these forces, and hence, it will be more difficult
to turn the kart...
However, the kart yet turns during cornering. How and why this takes place? Lets see what happened if the forces pressing the kart
rear shaft wheels are redistributed, i.e. one weight force will reduce while the second one will be increased by the same magnitude...
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From section Turning angles of steered wheels
...If steering wheel turning angles are wider then 15 degree, distributions from changes, typical for classical steering trapezoid,
appear in the studied scheme. The difference in turning angles increases more rapidly for inside and outside wheels. At the same time
the reduced value of the Ackerman angle is less than in the classical steering trapezoid accepted for comparison...
Modification of cross steering rod length is foreseen in design of the most modern karts by means of steering pin rearrangement into
a new position on a steering knuckle arm. Thus, Figure 15 shows the knuckle of a kart manufactured by Birel, in which such
rearrangement is foreseen...
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From section Steered Wheel Turn and Frame Twist Angle
...If a line is drawn through these support points, angle is formed between this line and the line parallel to bearing surface;
this angle will be called as a kart frame twist angle. It is absolutely obvious that this angle will depend on kart geometric parameters
(front axle width, wheel spindle length, wheel turn angles) and the difference in displacement of wheel support points during their
cornering. This difference in wheel displacement depends, in turn, on kart front axle parameters - king pin inclination angles and
wheel spindle length...
...It is assumed for the present stage of the research that displacement of wheel heel pattern from tire center closer to its
lateral edge will reduce the contact area. Hence, it will result in greater tire wrinkling. The tire deflection will also increase
enabling compensation of partially increase of movement due to wheel tilt...
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From section Kart Rear Axle and its Characteristics
...Minimal shaft wall thickness for each diameter is limited by CIK-FIA requirements and is givven in Table 1. As can be expected,
the sag increases with decrease of the shaft outside diameter. However, at the certain ratio between diameter and wall thickness
the sag can be the same to shafts of a different outside diameters. For example, for the shaft with outside diameter 50 mm and wall
thickness 2 mm the sag is the same as for the shaft with diameter 45 mm and wall thickness 3.2 mm. The graph shown allow to make a
comparative evaluation of shaft rigidity for different diameters with different wall thickness made from the same material...
The shaft sag depends also upon kart rear end width, it should be clear from the calculation model: the length of shaft console
increases with increase of rear end width at constant distance between bearing units. This, in turn, results in increase of
bending moment...
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From section Wheel Breakaway
...During racing, centrifugal force acts on kart when moving on the track at every corner. One of its components points
perpendicularly to the kart longitudinal axis. Elastic wheel rolling under its influence takes place under some angle to its
mean plane...
Contact area can also move relatively to bearing area; this movement is caused by tire slip relatively to track bearing surface at
significant lateral loadings and transition of wheels from rolling with breakaway to its slip. As a result, wheel rolling occurs
along the trajectory not corresponding to the direction of its plane upon coordinate x...
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From section Basic Operating Characteristics of Tires
...Tire design has the biggest effect upon force distribution in it... One should also take into account tire composition
because the tire can be unstable if it does not match its design...
It is the most important challenge for tire designers from viewpoint of safety and high results during race. Tires for wet track
are developed using all capabilitis in order to provide tire contact with track through water layer... Figure 104 shows dependence
of tire grip upon conditions of track cover...
When the pressure is significantly decreased, the central part of the thread deeply sags inside the tire, water is not removed
through the grooves and accumulates under wheel...
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User Reviews:
Well. I've read it. It has 235 pages of text. For all of you with physics and engineering degrees, you should love the detail in this book.
The first 148 pages is very technical, full of formulas that were difficult to understand, but the concepts could be grasped. It's like a master's class in go-kart physics/engineering. Pages 148-235 makes more practical application and reference the earlier material well. Once it got to the practical, the earlier stuff started making more sense. It has been very helpful in tying together some loose threads in my logic of setup.
It is the most thorough, up to date, and comprehensive look at the "witchcraft" of kart setup that I have read. I did find a couple of errors in the book. Understeer and oversteer are mislabel on p.11, and the section on Ackerman has some contradictory statements. Overall, a solid presentation. Hopefully I will be able to make setup more about method and science than trial and error. Will it make us 3/10 second faster at Nationals? I don't know, but I'm going to be a lot more comfortable blaming the driver now!
As to the price, everything in karting seems to cost about 10x more than you think it should, and this holds true here. It truely is written to a niche market and he deserves a payoff for his efforts. I recommend this book. I think those of you with a good grasp of setup already will get the most out it. As an intro to karting, it could be overwhelming.
Glenn Tillery, Alabama
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