"James Annan" wrote in message
...
Jay Beattie wrote:


So, why would it blow off if it is not over-inflated, or if there is
not
a gross mismatch between rim and tire?

How do you judge 'gross mismatch' other than with hindsight?

Rattles around like a hula hoop on a skinny kid. If it is within the
range of ordinary tightness (meaning that some effort has to be exerted
with your thumbs to get the tire on the rim), then there must be
something more subtle causing the blow off. I am curious to find out
what that is. -- Jay Beattie.