[python] Re: python stability, again...
- From: Dirk Bonne <dirk_bonne@xxxxxxxxxx>
- To: python@xxxxxxxxxxxxx
- Date: Mon, 31 Oct 2005 10:44:52 +0100
Hi Ray,
On 10/30/2005 09:32 AM, mtb@xxxxxxx wrote:
> I have made a couple of mods to the Frame Geometry and Stability program.
> http://rjs.org/Python/FrameGeometry.zip 2.8MB
> You can modify the wheel sizes visually and set the max speed to analyze.
>
> What I was then noticing was how much the size of the front wheel
> affects things. By adding a few kilos to the front rim (lots more
> mass) the possible stable speed range drops (ex. stable_1.cfg). Of
> course, there are a number of effects all related to the front wheel,
> like being able to move the pivot closer.
>
> One of the most important things seems to be how much the mass of the
> feet/legs on the pedals helps stability, which is fairly intuitive -
> imaging trying to coast with your feet off the pedals and steering
> with your handlebars - the python does not want to turn. I've tried!
On my flevo (positive trail) I have had the oppositve effect: I have
banged against the ground at speed because both feet unclicked (large
pothole I did not seen). Immediately the front side of the bike flopped,
and I fell.
> At large trail numbers, self-stability seems less sensitive to pivot
> angle than other factors. If the pivot angle lessens the trail, that
> is a bigger effect.
> Unfortunately, the program does not model how the bikes "feel" in the
> general sense...
>
> I tried to model Dirk's 20", and it seems it can be close to self
> stable with some reasonable, small, pivot input from the rider
> (torsional K in the model).
But the self stability seems to be only on 34km/h. Would that actually
also mean that from this speed onwards there is another effect (whcih
one?) active that makes bike handling different?
>
> I want to mount my vid camera on my back rack tomorrow for a weekend
> ride. We'll see...
> Vids are also now in the Internet archive:
> http://www.archive.org/search.php?query=python%20recumbent
> I also just noticed the a Google search for recumbent+python puts my
> page on top! http://www.google.com/search?q=recumbent+python
I think its much dependant on when google spiders last hit the webpages.
And probably it helps a lot that your page is a no frills page? I just
tried it to go to your website, and it was second now. The video is now
first!
dirk
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