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© 1998-2007 H. Pietschmann


 What is traction ?

why do we need traction?


resulting from

a specific FRICTION coefficient (ie friction between rubber and ground)
combined with

area of ground covered by the tire - FOOTPRINT

combined with

vehicle WEIGHT pressing a tire onto the ground

is a resistance between tire and ground.

If traction is less than the torque applied

a tire will start spinning.

In this case we say: "The tire lost traction" even though traction (resistance) did not vanish completely - it was just not enough traction to handle the torque.

1. Decreasing torque (backing off the gas) will help "regaining" traction.

2. If you need a high amount of torque to move your vehicle (uphill etc) you can create more traction by deflating your tires (creating a larger footprint). 

How wheel travel influences traction.


If one or more components of traction (friction, footprint, weight)

decreases (less friction [mud etc], smaller footprint, less weight)

traction will decrease!


If one or more components of traction (friction, footprint, weight)

increase in value (more friction [concrete etc], bigger footprint, more weight)

traction will increase!

Traction use of a 2WD - Traction use of a 4WD