Hydroplaning is a function of speed and the pressure on the contact patch. Bigger contact patch, higher speed, less weight = more hydroplaning. Cars hydroplane sooner than motorcycles which hydroplane sooner than bicycles.
I've ridden my vintage motorcycle in excess of 70 mph in heavy rain storms with a back tire that was nearly down to the treadwear markers and didn't experience any hydroplaning. It was on an interstate highway that had good drainage, I don't know that I'd want to try that on a backroad where I might encounter puddles. Modern motorcycles have a back tire about twice as wide as my 100 mm one, so they'd hydroplane at a lower speed. Motorcycle rain tires seem to support the theory that the tire engineers think that hydroplaning is possible on a motorcycle. I don't think it's possible to hydroplane a bicycle, which agrees with the tests that Avocet did back in the eighties.
John Barry <usazorro@yahoo.com> wrote:
> Sounds like another shot-from-the-hip Jobst theory.
>
> Anyone who has driven on good tires on a wet road, and
> then driven on bald ones on a wet road and not noticed
> a difference, would have to be either very distracted,
> or borderline comatose.
>
> Hydroplaning is a very real phenomenon, and to suggest
> that tread pattern could not have some bearing on how
> severely hydroplaning affected a tire just doesn't
> have their facts straight. I'll leave the posting of
> citations on the topic to the engineers here.
>
> John Barry
> Mechanicsburg (where bald tires wouldn't be a good
> idea tonight), PA, USA
>
--
Eric Goforth
Durham, NC, USA