17" rims

[rocco16 at sbcglobal.net (LEF)]

   here we have tires of the same age, but differing wear.  Rotating front to rear resulted in a
  clear handling shift - it now pushes considerably more in the turns 

  I would expect one tire having less tread depth than another tire with the same same age/cycles to be better.
  My question is about differing tread depth AND differing age/heat cycles.

   > Would the responsiveness of the "shaved" tread be offset by the increased hardness of many-times-recycled-and-aged rubber?

   Additionally, even 'old' tires, provided they were routinely driven, should be close to new as far as tread
  softness goes. 
    
  But this isn't the case; tires with many heat cycles/much heat input WILL be harder than the same rubber was when it was new.


  Routinely 'working' the tires (i.e. driving on them), keeps a steady flow of compounds moving to the surface /
  sidewall.  

  I'd like to know where this theory comes from.  I've done a lot of tire "fact-finding" and have never heard this.
  A compound can't flow to the surface.  A compound IS the surface.  It's the rubber, in its entirety.

    The down side to this is that those nice sharp edges of the tread blocks won't stay nice and sharp for long, so any advantage quickly fades away as the 'bite' looses its 'teeth'.  

  Allyn, Allyn, Allyn....tires don't get their bite from tread edges.  They get their bite from the rubber momentarily flowing into the tiny "holes" in the concrete/asphalt surface.
  If tires got their grip from edges, slicks would be like driving on Tefon.
  (Snow and dirt surfaces, on the other hand, need those edges....but not macadam.

  > Would the grip of new rubber be more desireable than the crispness/controllability/accuracy of the short, stiff tread on the old tires??

  I believe the stiffness actually works against you, as the better the rubber conforms to the road, the more contact area there is to aid in grip.

  I thought you agreed that shallow tread depth/stiffer tread blocks are BETTER than tall blocks??? ...as evidenced by your next statement.   Is this a typo or are you confused?  :)

  >   What would be YOUR preferrence?

  At the track?  If it's dry, shaved rubber hands down.  The closer to slicks the better.  The only reason for tread is water
  channeling / wet drivability.  The only reason treaded tires have tall tread is so they maintain their anti-hydroplaning abilities for a reasonable mileage.  People just won't buy a street tire they have to replace in 5k miles.

  I agree with this, even if you don't agree with yourself ( about edges giving bite).  :)



  Imagine the length of the contact patches are equal.  In the case of the larger wheel, the cornering forces will act over a larger arc of the tire bead, as it is occurring at a larger radius as compared to the smaller wheel.

  But (big but) the patches are not equal... in shape anyway.  And larger wheels do not influence patch size or shape.  Only tire diameters and widths determine contact patch size and shape.

  Additionally, in the case you cited, the belt area is a much larger diameter.  With steel belted tires, the tread deflection is
  spread around the entire sidewall (i.e. all the way around the tire).  Sure it falls off as you move away from the contact patch, but it's still felt all the way around.  In the case of the larger wheel + same sidewall height, there is more circumferential belt area to spread the load, and more sidewall to support it (laterally).

  I think you are assuming much there. And possibly attributing positive status to phenomena that may be irrelevant.  Sounds good, though!  :)

  Well it wasn't a goal to 'win' this one... We both learned something in the process.

  I'm learning more with every post. 

  I see your $0.06 and raise you... a blown Koni
  :)
  Al

  See your Koni and raise you a NIB  16v front wheel bearing kit. 

  P.S. - Larry, turn off the HTML in your email client, or just tell it to keep the format of the received email.  It makes in-line replys damn near impossible after converting back to text format.  
  Tell me how and I'll certainly do it!!  :(
  larry
  sandiego16v