I have similar concerns. I'm a little more reckless, and do go to 35 mph
and beyond, but I notice that my Hutchinson Carbon Comp 700c X 23 tires,
from 2001, have some cracking where the sidewall meets the tread. They hold
125psi (their rated max, and the pressure I run) fine, and the only issue
I've had is a flat from going up a sharp curb too hard (the presta valve
stopped holding air). I've been trusting that the belt will hold them
together, as well as the interior rubber and anything else that's not
cracked (just that exterior layer of rubber).

Should I replace these tires? If so, how can I maintain their condition
better? I suspect a standard commercially available rubber treatment for
automotive tires should suffice.

On Fri, 18 Jul 2003 15:05:38 GMT, Dan Musicant
wrote:

blow by me at probably 35 miles/hour on the steepest part ( !! ) but it
makes me shudder to think what would happen to them if they had a flat
or a blowout. I read a story of a guy who's a quadrapalegic now who had
just such an accident in my vicinity.

That tire was not on that bike more than about a month. It was one of
several cheap tires I bought a few years ago and they seem to have all
gotten stiff, somewhat brittle and even crumbly just sitting around.

--
Rick Onanian