[python] Handlebars mounted
- From: "25hz" <25hz@xxxxxxxxxx>
- To: <python@xxxxxxxxxxxxx>
- Date: Thu, 7 Apr 2005 22:20:51 -0400
Well, my friend and I decided to utilized the (finally!) nice weather and
quickly put some handlebars on his python
(http://bikes.jkcc.com/python%20clone.htm#pythonmd) to a) make a place to
mount the gear changers and brakes and b) to see if it helped the rider to
control the bike. Unfortunately, no pictures at the moment . . . maybe I
can snap them tomorrow. Point a) worked, point b) did not. While they
haven't changed the characteristics for riding with no hands like usual, he
said that when he uses them, he loses concentration on his body balance too
easily and he can't compensate fast enough with the handle bars.
His initial basic complaint is still present and that is that he is not
stable enough on it, to his liking. I keep trying to remind him to get into
the mindset that he had when he first started riding a bike and that all it
takes is a little time and practice. One thing I did like about watching
him ride is how fast they are with seemingly little effort. When I try to
ride it, I get major pain in both ACLs (the ligaments on the inside of the
knee) but I am still committed to building a new seat for mine and adding
handle bars as well. I don't know if I'm just trying to fire the wrong
muscles to steer the pythons or whether my bad knees will hamper my ability
to learn to ride them. I was hoping handle bars would help take the strain
off my knees for steering inputs. At the very least, the handle bars did an
excellent job of saving the seat mesh from taking major damage during
wipe-outs :)
About the bars . . .
The bars were made out of plain 1" EMT with a 90 degree bend in them. They
are mounted in pinch sockets just forward of the pivot, on the chainstays.
I reasoned that the closer they are to the pivot, the more natural the
turning effort would feel as opposed to getting a lot of "tiller" effect if
they were mounted further forward. The steel I used for the socket was
likely part of the problem as it didn't seem to be strong enough. Will
rectify that and try it again. Possibly part of the handlebar use problem
was due to the fact that they weren't as rigid and secure as they should
have been.
I was also thinking about two aspects of the stability issue. First, our
pythons have a pivot angle of about 70 degrees. Flatter than most others by
a few degrees and so they are likely a little "freer" in steering effort.
This ease of steering movement either helps the learning process by making
it easier to correct the steering, or, it might hamper the learning curve by
making it too "floppy" in the steering department. It might be a case of
the glass being half-full, or half-empty point of view. The second thing I
was thinking about was how low our pythons are, and in turn, how low the CoG
is. If the CoG is too low, it might make riding more difficult because the
"margin of balance" is smaller than if the CoG was higher up, like most of
the other pythons seem to be. With a higher CoG, the bike needs to lean a
larger distance left or right before you wipe out, and that gives the rider
more time to react with smaller correction inputs. With a low bike, it
seems that you have very little time to react to balance issues and your
corrections need to be more precise than with a higher bike. I think our
pythons would be fine to ride after someone has already learned how to
control a higher/taller python. I would also think that a lower python
would be a little more stable than a higher python at higher speeds on a
down hill. Again though, we need to actually GET THEM on a down hill to
confirm this :)
While I'm making slow headway on my workspace, I'm still not quite ready to
start building again, but hopefully in a week or two. The nice thing is,
that both pythons can very easily have their pivot angles changed to mid to
high 60s by simply notching the main backbone, closing the gap, and welding
it up again.
Will post pictures of the handle bars when I get them.
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