Zero scrub radius is not necessarily desirable larger scrub radii lead to less

Zero scrub radius is not necessarily desirable larger

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the self-centering effect. Zero scrub radius is not necessarily desirable - larger scrub radii lead to less steering effort (especially on vehicles without power steering), but more force applied to the steering components by road surface imperfections, braking, etc. Zero scrub radius isolates the steering from these effects but can lead to a "dead" feel for the driver which is undesirable, especially on performance vehicles Scrub radius: The scrub radius is the distance in front view between the king pin axis and the center of the contact patch of the wheel, where both would theoretically touch the road. The kingpin axis is the line between the upper and lower ball joints of the hub. The inclination of the steering axis is measured as the angle between the steering axis and the centerline of the wheel. This means that if the camber angle is adjustable within the pivot points the scrub radius can be changed, this alters the width and offset of the tires on a vehicle. The term scrub radius derives from the fact that either in the positive or negative mode, the tire does not turn on its centerline (it scrubs the road in a turn) and due to the increased friction, more effort is needed to turn the wheel. Large positive values of scrub radius, 4 inches/100 mm or so, were used in cars for many years. The advantage of this is that the tire rolls as the wheel is steered, which reduces the effort when parking. This also allows greater width in the engine bay, which is very important in some compact sports cars. If the scrub radius is small then the contact patch is spun in place when parking, which takes a lot more effort. The advantage of a small scrub radius is that the steering becomes less sensitive to braking inputs, in particular
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12 3.Literature review 3.1.Introduction: Tires are the most important parts of a race car. They have to transmit all drive, brake and steering forces to the road through a very small contact patch. This makes it very important for a car to keep the tires in optimal contact with the road at all times. That is the task of the suspension system. In case of a race car, the suspension system can be desi gned specifically for that goal, at the cost of driver comfort. The wheel and brake disc are connected to the upright by bearings. Carbon fiber rods with ball joints on each end connect the upright to the chassis. One of these six rods (the inclined one) is not mounted to the chassis, but to a rocker. If the wheel moves up with respect to the vehicle body, the upright pulls on the rod, which in turn causes the rocker to rotate about its pivot point. A spring-damper is connected to the bell crank on one end, and to the chassis on the other. So by rotating the rocker, the spring-damper is compressed. The spring-damper system consists of two subsystems: the coil-over damper itself and the anti-roll system. The coil spring absorbs the energy from a bump by compressing, and releases it again at an uncontrolled rate. The spring will continue to bounce until all of the energy originally put into it is dissipated. Dampers are used to control this energy
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  • Fall '16
  • sumant tadepalli
  • Suspension, Camber angle, Vijay, Roll Center, SRI HARSHA

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