I don't know if this belongs in this forum, or the wheel /tire forum, but i figured it dealt with suspension so here goes.

is there a way to determine how much the contact patch decreases as the degree of (negative) camber increases? i.e. is there a formula where you can input the tire size (205/40r17) and deg. of camber, (and or ride height) and determine the area of the contact patch?
i don't know if there would be any useful applications if a formula like this existed, but i was just bored and started thinking. anyone's $0.02 would be appreciated

 

trigonometry? seriously.

 

The tire isn't rigid but flexes so the contact patch of a real tire does not change as much as a rigid tire would. It still decreases with camber, though. No way to actually calculate it since you don't know enough about the tire to determine how much it will flex. You could use trig as a broad approximation, but the real tire will be different.

Anyway, the total contact area will remain the same since the forces are the same, but the shape will change (gets longer) with increasing camber.

 

I'm making the assumption that trying to use the required trigonometry to figure out how much of the tire (assuming a tire is rigid) would have kept him busy enough.

He asked if there was an equation, and there is. But it doesn't account for all the variables.

 

Contact patch area is a function of tire construction and weight at that corner. It has nothing to do with camber. That said, lots of camber will result in the contact patch to be at least partially on the sidewall and since the sidewall is not designed to be driven on it will produce less than optimal grip.

regards,
alan

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 00R101 &raquo;</TD></TR><TR><TD CLASS="quote">Contact patch area is a function of tire construction and weight at that corner. It has nothing to do with camber. </TD></TR></TABLE>

I'd have to disagree.

Look here for some excellent tech stuff.

http://www.nittotire.com/tech_interactive.asp

 

00R101 is right about the patch area. The area must be the same because the applied pressure is the same. Increasing negative camber will reduce the lateral portion of the tire in contact with the road. Thus the patch grows longitudinally b/c the applied pressure is the same.

Edit: I didn't download the Nitto thing, though.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 00R101 &raquo;</TD></TR><TR><TD CLASS="quote">Contact patch area is a function of tire construction and weight at that corner. regards,
alan</TD></TR></TABLE>

Weight and air pressure. I don't think tire construction matters at all in determining the area of the rubber that meets the road.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by rapid_roy &raquo;</TD></TR><TR><TD CLASS="quote">

I don't think tire construction matters at all in determining the area of the rubber that meets the road.

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It will determine the contact patches shape at a given load or roll angle on the vehicle (for the most part). Thats probably good stuff to know if your racing...