On 25 Dec 2002, at 13:21, Andrew Grebneff wrote:

(snip)

> Quite the opposite. The genuine ones have huge rain channels designed
> to pump water away from the contact patch. Also added silica is
> increasing grip. Soft rubber compounds also (though these days they
> don't waear at a horrendous rate, as earlier performance tires did).
> The only problems might be with aquaplaning with WIDE tires on deep
> water... this won't happen unless you hit a decent puddle. But then,
> even narrow tires wil aquaplane on a puddle... as I have experianced.
> A genuine performance tire gives hugely better performance in every
> respect (except ride, and even this doesn't necessarily suffer). BUT
> they are admittely more prone to being pinched between the rim and
> curbs or sharp-edged potholes.

(snip)

Deep water doesn't happen too often during races but it did one year at
Sebring (24hr or 12hr?); it was a downpour which couldn't drain fast
enough.  The TR's & MG's with narrow tires (it was a long time ago, ok?)
were passing the big guys with fat tires who were forced to slow to a
crawl because of aquaplaning.

Unfortunately, this kind of water is not that uncommon off track.  I'm
sure tire technology is now well above what it was that day.  But I think
given enough water, ANY tire will plane, the more contact area (per unit
weight?) the faster it will happen.  Exotic rubber compounds or silica
don't mean diddly once there's a layer of water between the patch & the
road.  I do know it can be a hell of a scary experience at high speeds.
Been there.  Ain't going back.

//Jack