skidpads

Skidpads are a circular test surface used to measure a vehicle's lateral grip and handling by driving around a circle with a fixed radius and steering input. The test provides a controlled environment to quantify tire-road friction and overall vehicle dynamics under lateral loading.

Typically conducted on a flat, well-prepared surface, a test vehicle is driven at a chosen speed along a circular track of known radius while maintaining a preset steering angle to sustain the path. Lateral acceleration is calculated as a = v^2 / r, and the usable friction force is μW, where μ is the tire-road friction coefficient and W is vehicle weight. Sensors collect data on lateral tire forces, yaw rate, and slip angles to determine peak μ, response, and handling characteristics. Tests are repeated across speeds, temperatures, and tire types.

Applications of skidpad testing include tire development, vehicle dynamics evaluation, and calibration of stability-control systems. Skidpad data help compare compounds, assess grip under different conditions, and support performance tuning. Limitations include dependence on surface condition, cleanliness, temperature, and contamination effects; results may not translate directly to real-road scenarios, and tests require appropriate safety measures due to the risk of loss of control.