Mike,
You don't hydroplane on bicycle tires? Maybe you just aren't going fast enough. ;)
I see the point about there being a difference between auto tires and skinny bicycle tires. I was thinking more of what occurs with a 27" x 1-1/4" or a 35mm 700c tire though (think borderline cyclocross tires), as that's what I frequently ride.
I do notice increased rolling resistance in some situations, and tread pattern could seem to potentially play some role in diminishing the effect.
Obviously, there's some point at which the weight becomes low enough, and the surface area becomes great enough that tread pattern becomes a factor. Does someone out there on the list know where that point is?
Regards,
John Barry Mechanicsburg (now cold as well as wet) PA, USA
> On Mon, Mar 31, 2008 at 5:00 PM, 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.
>
>
> Sounds like you're comparing bicycle tires to car
> tires?
> Car tires are affected differently due to their
> rectangular footprint, which
> reduces their ability to purge water.
> I have raced for years in wet and dry (not while
> comatose or distracted).
> *Any* difference in cornering traction in wet
> weather (where the tire is
> the cause) is from the casing deflection or rider
> skill etc... and *not*
> from the fact that it was treadless.
>
> >
> >
> > Hydroplaning is a very real phenomenon,
>
>
> t's not really a phenomenon. It's more basic
> physics and again, your
> comparing a car vs a bicycle.
> The round shape of the bicycle tire prevents hydro
> planing much better than
> a car would.
> that should be pretty simple to understand.
>
> 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.
>
>
> It does have bearing. Just the kind you don't want
> from a road tire.
> Please tell me how having treaded road tires helps
> you fend off
> hydro-planing? Or aids in cornering?
> This argument is old and has been disproven many
> times over.
>
>
>
>
> > 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
> >
> >
> >
> > >
> > > Anyway, here's Jobst on the subject (found on
> line).
> > >
> > > *snip from Jobst*
> > >
> > > * Tread patterns have no effect on surfaces in
> which
> > > they leave no
> > > impression. That is to say, if the road is
> harder
> > > than the tire, a tread
> > > pattern does not improve traction. That smooth
> tires
> > > have better dry
> > > traction is probably accepted by most
> bicyclists,
> > > but wet pavement still
> > > appears to raise doubts even though motorcycles
> have
> > > shown that tread
> > > patterns do not improve wet traction.*
> > >
> > > */snip Jobst*
> >
> >
> >
> >
> >
>
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> >
>
>
>
> --
> Mike Scammon
> Menlo Park, Ca.
>
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