[python] Re: max downhill speed --lost mail, second try

  • From: "Daryl Bender" <darylb@xxxxxxxxxx>
  • To: python@xxxxxxxxxxxxx
  • Date: Tue, 10 May 2005 17:18:56 -0400

I haven't ridden a Python yet so anything I say is most likely crap but
wouldn't the wheel wander at low speed if you weren't on the bike but just
pushing it (no weight on the pivot)? I would think that within reason
loading the pivot - weight, ground effects, whatever, would tend to *try* to
keep the wheel straight.
 
The problem I see is that given that speed forces generally happen as the
square of speed I could also see that this linear approach may get you some
extra KPH but the inevitable will soon "rear it's head" again at a somewhat
higher speed. The square forces overpower the unity forces no matter how big
they initially are and eventually force the "shopping cart caster" into its
otherwise stable position.
 
Take rolling resistance (varies with v**2.5). If your front wheel gets even
slightly off straight isn't that like a front brake applied with your wheel
turned forcing the bike to want to fold up?
 
I'm guessing we need to pull a correcting "cube" out of our panniers :-D
Daryl

-----Original Message-----
From: python-bounce@xxxxxxxxxxxxx [mailto:python-bounce@xxxxxxxxxxxxx] On
Behalf Of Dirk Bonne
Sent: Tuesday, May 10, 2005 3:10 PM
To: python@xxxxxxxxxxxxx
Subject: [python] Re: max downhill speed --lost mail, second try




mtb@xxxxxxx <mailto:mtb@xxxxxxx>  wrote: 

At 07:23 AM 5/9/2005, you wrote:



You make the case for "ground effects" :-) 

-----Original Message----- 
....snip 
 The faster the coasting, the higher the friction gets, and at some point
the friction pushing backwards likely approaches the ability of your weight
to keep the pivot at it's lowest point, and keep the bike running straight, 


That would be good, since air resistance is also a square law. I had thought
of adding lead weights to the spoke nipples  to increase the gyro
stabilization, a linear effect...


Hmm, would it not be that it is exactly the opposite, that the turning of
the wheel makes it wierd to ride. And that we should instead try to minimize
it instead of maximizing the power exected on the pivot. 

Dirk



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