Gereedschap

Bericht over pogingen virtual rush door Matt Weave

Gepubliceerd op 26 februari 2002 00:00 (75 keer bekeken) 0

Een bericht van Matt Weaver in een buitenlandse mailinglijst zorgt voor een verklaring van de problemen zoals Fast Freddy Markham ondervond.

In reading some of the messages on the recent Virtual Rush
attempt, I thought I'd note a few things as I'm quite familiar with it all.

The hour record is non-trivial. The dynamics above 50-MPH are
nothing like 25 or 30-MPH. Four-fold dynamic pressures applied to bodies
intrinsically capable of far more lift and moment. The standing-start 56-mile
Dempsey-MacCready Prize requires nearly 57-MPH cruise for the
entire hour.

The gap from 50 to 56 is something like 5 or 6 previous world hour
records back to back, and at a higher level. For a given vehicle,
increasing speed from 50 to 56 requires nearly 50 percent more power. Already
given top athletics, substantial improvements in vehicle efficiency are
necessary. Even with the potential to make such a leap, given the exactness
necessary, a failed attempt is understandable.

I know firsthand the Virtual Edge/Rush is markedly more efficient
than the Kyle Edge. I've tested both on Las Vegas. Arguably Fred is
riding a vehicle that carries a human being from one point to another with
less power than any other currently in existence - less than even the best
solar or supermileage vehicles. There's something unique to what he's
attempting beyond the speeds. The fact that it is a bit like tuning and
tweaking a Ferrari or say mastering an experimental fighter jet is known well
enough, as are potential "fixes" to make it all "user friendly" in light
of the implicit aerodynamics/dynamics that I've modeled and know well
enough.
I know a little of what Freddy Markham and Gardner have gone
through in recent weeks. They've really overcome some big hurdles of which
I'll note a few. First Freddy mastered the strange experience of piloting a
fast low bike by video, and the many technical details that must be just
right for the rest of the bike to work. He also dealt with being "locked
in" to the tight enclosed space of the streamlined bike with no immediate way
out before the ventilation can kick in with speed. He learned to deal
with impending claustrophobia just as I did even as one not prone to
such. He dealt with the challenges of starting/stoping under video.

As chance would have it, he dealt with far more crashes. I've
only tipped over twice while stopping and once suffered a tire blowout. Fred
first went down in the worst gravel he could ask for in a velodrome test
after having waited long enough locked in the bike, and now on Las Vegas during
his first attempt before he even had a chance to get up to full speed yet
still at nearly highway speeds. Fortunately the bike is proving very
robust. He dealt with the gusts at Las Vegas that can indeed be very intense,
brief, and localized. It will be dead calm, and then easily a 30-MPH
burst will hit where you are and blow away just about everything you have
around you. It's actually possible for a fast bike to cope with such
conditions, but that's another matter.

I have no doubt Fred could have set a significant record. I don't
think he doubts it either, and he's more than eager to get right back in
and go again. He may have presumed to be able to "compensate" for a
flawed frame as much as I did. The frame may need further modifications or get
scrapped altogether.

The speed records are definitely in potential flux now, and
there's a lot more to come. The new "territory" is significant in a way yet
just starting. Why do we do it? I'm not sure, but I suspect something
of meaning is behind it all so we endeavor. It's more than because
it's there.
Some day we'll know. Many thanks to all those that have been
there through the failed record attempts along the way.

-Matt
p.s. Funny thing I ventured onto the rec.bicycles.racing
newsgroup (I'm a newsgroup newbie) and was reminded of certain mentalities. I
suspect the better and more frequent the top-speed performances in the
unlimited HPV realm, the more awareness and regard all "non-standard" machines
(recumbent, HPV, etc...) will have - as simple as that may be. Granted each
and every vehicle "class" and any competition associated with it is best
respected accordingly as well.
Zie ook: