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Q & A: Ackerman's principle

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Most recent answer: 10/22/2007
Q:
What's Ackerman's principles?
- Heikenwaelder Christian (age 18)
Kemptville College, Kemptville, Canada, Ontario
A:

Hi Heikenwaelder,

Wow, great question! I’m no expert on cars, but I did look up some information about Ackerman’s principle on the web; I hope the information I give you is sufficient. Basically Ackerman’s principle is a method of wheel alignment that puts the two front wheels of a car at slightly different angles. This makes all the wheels roll around a common point during a turn:

 


(This picture was taken from https://en.wikipedia.org/wiki/Ackermann_steering_geometry.) As you can see from the picture, the front inner tire has to make a tighter turn than the front outer tire. If the tires are not aligned properly so that they turn at different angles, they "fight" each other during a turn, causing them to wear down faster and the car to go slower. This is particularly important for race cars, which are designed to go as fast as possible. However, it is also important for normal consumer cars because properly aligned tires mean easier steering, better traction, more efficient fuel use, etc.

There are a lot of gory details when it comes to aligning everything in a car so that the wheels will turn properly like this, but like I said, I’m no car expert. For more information, take a look at the above website.

 


(published on 10/22/2007)

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