A number of modern high performance tires have nylon belt end caps or other nylon parts. The tires on my 600SEL flat spot horribly in winter. I had a set of Goodyear tires that sat on a car for a couple of years. When I put them on my Fox, the flat spots never went away probably due to the Fox being so light. Goodyear replaced them due to the "ride disturbance". It was bad. 

Dennis

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of Dave Mcneely
Sent: Monday, May 10, 2010 7:40 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: Tire size questions

Nylon tires thumped.  Don't know about rayon.  Some newer tires have rayon, however.  I don't know why.  My brother tells me that radial cords smoothed out the thumping even more than the move from nylon, but I do know that nylon thumped.  DMc

---- Karl Wolz <wolzphoto@q.com> wrote:
> My recollection is that nylon cords were introduced to get RID of the
> thumping; it was rayon cords that had
> "memory issues".  OTOH, I could be wrong - it's been many years ago.
>
> Karl Wolz
> |
> |From the link you provided, I see that the tire includes nylon cords.  I
> |did not know that any modern tire included nylon in the construction.
> |Perhaps because Hankook markets them as a "summer tire," they find nylon to
> |be satisfactory.  Have you noticed the thumping phenomenon I mentioned?  Do
> |you guys drive them year-round?  I would assume so.
> |
>

--
David McNeely