David T. Ashley wrote:
> "Outback Jon" <teammft@ver.no.sp.am.izon.net> wrote in message
> news:gTZcj.4858$nh7.1013@trnddc01...
>> bob prohaska's usenet account wrote:
>>> After trying both anti-fog coatings and Fog City, I'd have to
>>> agree
>>> mostly with Ben. Fogging faceshields are really a problem only at
>>> low speeds, low temperatures and high humidity.
>>
>> Can even be an issue at high speeds if one is behind a fairing. If
>> I
>> stand up, the vents in my helmet work well, and the fogging clears,
>> but when seated on the bike, the windshield directs the air in a
>> bubble that doesn't let the chin vent work.
>
> Ah, now my problem is making more sense. I have a windshield
> thingie, and I know that the airstream touches only the top of my
> helmet. So, the chin vent is relatively ineffective. Never thought
> about that.

One thing I've noticed is that commuting around town in cold weather I
tend to get fog on both the visor and my glasses. When I've been on
the road for an hour or so then it goes away and stays away until I
stop somewhere long enough for everything to warm up or cool down.
It's not entirely speed related--while I get less fog at 70 I still
get some for that first hour or so unless I leave the visor cracked
just a bit, then after an hour or so (might be a half hour, might be
15 minutes--I've never put a stopwatch on it) I can close the visor
completely and no problem. If I stop for lunch then I have the same
thing happen afterward.

I've been assuming that this has something to do with visor and
glasses coming to equilibrium temperature, but I wouldn't swear to
that being the cause.

--
--
--John
to email, dial "usenet" and validate
(was jclarke at eye bee em dot net)