Hi Gerald,
Thank you for the reply and the information.
I spent some more time with my Python and this is what it turned into:
http://myrecumbent.blogspot.ro/2013/05/python-turned-peregrine.html
Regards, Tiha
On Tue, May 21, 2013 at 1:58 PM, Gerald <bepb@xxxxxx
<mailto:bepb@xxxxxx>> wrote:
__
Hi Tiha,
my congratulations to you new python, nice work.
I ride both, a python with 405 (20") wheels and one with 622 (28")
wheels.
Both ride nice but also quite differently.
Beside the obvious better maneuverability due to the shorter
wheelbase, the 20" wheel passes more or less under by legs while
cornering. This makes it even more easy to take tight corners.
With my 28" Python, the front wheel is actually between my legs, and
together with the seat, this limits the maneuverability
significantly. But for speed on flat, open roads, the 28" python is
the fastest (human powered) bike I have ridden yet.
When you pick a big wheel, you should consider the required in seam
length of you legs!
Check http://en.openbike.org/wiki/Wheel_Sizes.
Actually, for a first python you made a clever choice :-).
As for moving the pivot behind the seat - one point certainly is if
the seat is mounted to the rear or the front part. If the seat is
mounted to the front part, the overall steering will change
dramatically because you can't steer with you legs anymore. Don't
know if you could consider it a python at all.
Best regards
Gerald
On 13.5.13 17:56 , Tihamer Juhasz wrote:
Thanks Philip. I made up a drawing for the front section, the
wheel cage, in a 3D design sw to calculate the distances and the
bend angles. Otherwise there was no precise plan before starting
to build it. Just made some calculations on paper and did the rest
of design on the fly while building it. The basic idea to run
everything horizontal as much as possible was made prior to
drawing or fabrication. Just two wheels and a straight line
inbetween. Turned out really simple indeed.
Tiha
On Mon, May 13, 2013 at 5:14 PM, Philip Hahn
<everphilski@xxxxxxxxx <mailto:everphilski@xxxxxxxxx>> wrote:
Tiha,
I love how clean your bike looks. Did you make up drawing
prior to fabrication or did you go by trial and error?
Beautiful Python!
philip
On Mon, May 13, 2013 at 6:42 AM, Tihamer Juhasz
<balamber@xxxxxxxxx <mailto:balamber@xxxxxxxxx>> wrote:
Hi all,
Made some more decent pictures and shared them in a Picasa
album again:
https://plus.google.com/photos/115292543199069523585/albums/5877419428757741505?authkey=CK7Kp9yb07HK4QE
I hope the pictures explain how the pivot works. It
actually works well, but it seems not strong enough to
last long. Will see.
I presently ride the bike like an agitated orchestra
conductor, waving around randomly with my arms, but its a
lot of fun. Its really refreshing to learn something this
basic at this age. I make steady progress each time I take
out the bike, so its reassuring too. Any tips on riding
are welcome. I did not mount a handlebar yet, so I learn
hands free.
A few questions: how much does the trail and wheel size
influence the riding behaviour of the bike? Are bigger
wheels better for riding stability? Has anybody tried to
have the pivot behind the seat? I would imagine that pedal
induced steering would be even less if the pivot was right
behind the seat support point, so almost at the center of
gravity and behind the rider hip joints. And one more: how
about having a reversed python? That is, move the pivot
back to the hind wheel and have it mirrored (at 115 degr
(180-65) or having it at 65 degr. This would be a rear
steered bike I know, but there are a few which work.
Thanks,
Tiha
