[python] Electrified!
- From: Rhisiart Gwilym <Rhisiart@xxxxxxxxxxxxxx>
- To: python@xxxxxxxxxxxxx
- Date: Wed, 28 Nov 2007 08:29:30 +0000
The Python trike has been done, and it works. A trike can slowly climb
to the top of any hill, without falling over, even if you do get passed
by people walking their bikes, but you do need a low enough gear that
you are not straining to get there: because you can use lower speeds on
a trike than you could use on any bicycle, bike gears generally don't go
as low as you need.
The only Python trikes I know of are deltas (two rear wheels), but delta
trikes are dodgy beasts in corners and under brakes, unless the seat is
even lower than on most Pythons. Tadpoles (two front wheels) are
stabler, but a Python tadpole would be very complex.
A fairing for a Python would have to deal with centre steering. Would
you articulate the fairing in the middle, like a tram? If the front end
and bottom bracket could move from side to side within it, the nose
would be huge, even by faired recumbent standards.
Siwmae George, Dirk,
I suppose using 20" wheels would help in down-gearing everything. I'm
not -- yet! -- so shot that I need to creep ultra-slow uphill. About
a brisk walk is fine.
I've been pondering a long while on whether to go for Bram Smit's or
Paul Sim's or Henry's tilting deltas, to deal with the instability;
or just to make it wide and low, with a slight canting inward of the
rear wheels, but fixed upright. There are already plenty of tried and
proven examples of that last. And we've just seen that marvellous
video of Nobuo's tremendous downhill charge on a non-tilting delta.
75.5 kph, I seem to remember (Respect again, Nobuo!) I was just
driving my -- er -- C*r down a steepish hill at 50 mph and thinking:
"Bloody hell! I don't know if I'd dare to do this speed on ANY bike."
But clearly, despite the risk at the limit of tipping, deltas do seem
practical.
It seems to me that in any case, alternative back ends, breaking the
bike at Jurgen's rear-suspension joint -- which I really like for its
simplicity and effectiveness -- allows you to play about with
different forms of bike and trike. I've considered for a long time
that FWD recumbents should be thought of really as unicycles,
strictly speaking, but always towing dumb trailers of one kind or
another, on which the rider happens to sit. (Except for the Kalle)
Because of the big bulbous fairing front end that's mandatory for a
centre steer, if you integrate it with the back end fairing, I'd
already pretty well decided to articulate it into separate parts, to
get a slim, close-fitting front end fairing, and a separate back-box.
Some work's been done already by several researchers into side
profiles which have a balanced response to cross-winds, so that the
bike/trike doesn't veer wildly if hit by a side gust. In the case of
several well-tried fully-faired road bikes -- Coyote Rotator, for
example -- this seems to work in practice. The other thing to work
out, I suppose, is balancing the weight distribution of the front-end
fairing, so that its weight doesn't cause wheel flop: 'Gill-cover'
wings lapping backwards behind the articulation joint, to balance the
nose-cone, I think.
Clearly, I'm going to have to try out both trike and bike trailers
for my little faired unicycle, because I have to have a go at the
pure original two-wheeler when the weather's good, and I'm on flat
terrain. Sooner or later we all have to commune with Jurgen's
original inspiration, and learn to float along on the
handle-bar-less, sinuously-hip-steered two-wheeler......
Dirk, I think there's now a widespread public bike rental in Paris
too, and working well for a large crowd of delighted
Parisians/Parisiennes. You can pick up a bike at one point, and leave
it again at another. One-way journeys catered for.
Assuredly, I suspect, there will be a big growth in practical use of
many of these forms that we are using already, or still developing,
or dreaming into being, as the global energy catastrophe strikes over
the next five years or so.
Cof, RhG
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