Contact patches

[QSHIPQ@aol.com]

Dave E. writes:
>no jeff, a narrower wheel does *not* change the *size* of the contact patch,
>unless tyre pressures are different.  again, this is elementary to the
>wheel/tyre debate.

Sure it does, Dave.  FE, put a 255/50 15 @ 32psi on a 15X6 stock audi turbo 
quattro coupe wheel.  What happens to the tread near the sidewall?  What 
about overall diameter?  Put the 255/50 15 @ 32psi on a 15x9 Urq racing rim.  
Any difference in contact patch?  Elementary to the proper sizing of rim 
width to tyre width.  We could speak of the contact patch of a 245/40 17 on a 
17X7 in RS2 wheel too I suppose. ;)

Try www.thetirerack.com.  They do a fine job of explaining the elementary 
wheel and tyre questions.  Plus sizing is in there for you too.

Scott Justusson