Just failed the CA DMV motorcycle popsicle test (and I thought Ihad passed)

Discussion in 'Bay Area Bikers' started by Joe Mastroianni, Feb 19, 2013.

  1. Joe Mastroianni

    Twibil Guest

    Come back, sleepy-head!

    Here you've got us all sitting anxiously on the edges of
    our seats, wanting to hear the carefully reasoned logic
    explaining how three-wheeled tricycles and two-wheeled
    bikes can steer the same way -even though that defies
    physics- and now you're going to run away and leave us
    all in the lurch instead of educating us?

    One would think that since you've actually got a willing
    audience for the first time in your life you'd be happy to
    take advantage of the fact, but no.......

    I wonder why that could be?
    Twibil, Mar 17, 2013
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  2. Joe Mastroianni

    Mike Young Guest

    Dude. Just stop already. Reasoning about physical processes is not
    something you do well.

    Lateral loading is dominant in "high speed" turns; negligible at "low
    speeds". Geometry, the relationship between the front wheel and rear
    wheel tracks, dominates at "low speeds." This is clearly what was meant
    by "At low speeds the bike follows the track ..."

    You can shove your teaching credentials where the sun doesn't shine.
    Attached to your name and posting history, they talk only to deficient
    selection standards.
    As though to a 4 y.o., then. Countersteer initiates a lean. Lean
    pertains to lateral loading. Toppling moment, coning angle, and camber
    thrust are relevant when talking about "lean" and "lateral loading" in
    context of steady state turning for two wheel, single track vehicles.
    This is in a "high speed" turn, as defined above.

    Lateral loading is negligible in "low speed" turns, by definition. The
    last time I walked a bicycle up the driveway, the bike followed where I
    pointed the front wheel. Was countersteering or high level thought
    processes involved? I don't know, but I do know without graph paper or
    slide rule that neither was necessary or relevant.

    Really, forget the teacher-to-the-stars spiel. What a jackass you must
    be, to have needed it as a cudgel in front of a class.
    Mike Young, Mar 29, 2013
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  3. Joe Mastroianni

    gpsman Guest

    <spit take> And all you had to do to counter the effects of gravity
    was add 2 feet to the 2 wheels! Newton's ghost must blush at the
    mention of your name...
    How would you refer to someone who has apparently not even bothered to
    glance at the Wikipedia entry on two-wheeled vehicle dynamics...?
    gpsman, Mar 29, 2013
  4. Joe Mastroianni

    Mike Young Guest

    I'm saying lean is irrelevant at low speed. Steering geometry suffices.
    All you're pointing out is that the external force substituted for the
    (unneeded) countersteer. Blush deeply indeed.
    Did Newton use Google to investigate his apple phenomenon? I say thee
    nay. His observations pre-date the lightweight wikipedia collection of
    knowledge. (I'll take a peek later. Sounds cool.)
    Mike Young, Mar 29, 2013
  5. You've only just worked that out?
    The Older Gentleman, Mar 29, 2013
  6. Joe Mastroianni

    gpsman Guest

    No, you said walking a bike is identical to riding a bike.
    Give your bike a shove down a grade, let go and measure how long the
    steering geometry keeps it upright.
    No, I pointed out when one walks a bike they hold it up instead of
    relying on balancing against gravity.
    He was smart, you're stupid.
    Fascinating... and awfully convenient for the Wikipedia to have those
    observations to reference!
    Excellent choice of timing...
    gpsman, Mar 29, 2013
  7. Joe Mastroianni

    Twibil Guest

    (Mildly) You seem to be confused: nobody said
    anything about being a "teacher to the stars", nor was
    there anything about "cudgeling" a class. Making up
    your own facts tends to get you laughed at on Usenet.

    (My! The man completely misunderstands the physics
    of a moving motorcycle, and appears to be proud of it!
    The interweb is full to overflowing with examples of the
    Dunning-Kruger Effect!)
    Twibil, Mar 29, 2013
  8. Joe Mastroianni

    Twibil Guest

    (Sigh) It isn't. And it doesn't.

    Unless you have feet paddling along the ground to hold
    you upright, you turn your motorcycle exactly the same way
    at low speeds as at high: you intitiate the turn by
    countersteering, and as the bike falls into the turn you steer
    into the turn enough to keep the bike from falling over to the
    inside of the turn.

    If you try to turn a motorcycle any other way it will fall
    right over, and that's really all there is to it.
    I should have known. First the "I already know all
    about the subject" followed by "Google doesn't know
    anything anyway".
    Twibil, Mar 29, 2013
  9. Joe Mastroianni

    Twibil Guest


    I didn't know you felt that way about me!

    Twibil, Mar 29, 2013
  10. Joe Mastroianni

    Mike Young Guest

    :) I hate doing this, but I agree 100%. If instead of a bicycle, you
    picture the much more considerable mass of a motorcycle, the need to
    balance upright trumps contact patch dynamics and steering geometry.
    Don't start. ;)
    Mike Young, Mar 29, 2013
  11. Damn. Sorry about that. MacSoup auto-kills the posts after 14 days and I
    didn't read the attributions properly. Thought it was Shumman he was
    replying to.


    Na,h fukkit, let the comment stand ;-)
    The Older Gentleman, Mar 29, 2013
  12. Joe Mastroianni

    Twibil Guest

    Damn cockey -strike that- cockney Brit.

    "Harry Potter" sells ten zillion copies and suddeny
    they *all* think the Sun shines out of their ass.
    Twibil, Mar 30, 2013
  13. Joe Mastroianni

    MikeWhy Guest

    You might be amused to know that eternal-september, my usenet posting
    host, went down and stayed down for 4 days shortly after I posted the
    above. Something about it apparently shook the whole fabric of reality.
    And on reflecting further, the following came to light.

    Upthread, Gpsman had chided me for not bothering to check his definitive
    fount of deep learning (wikipedia) before posting. "Spit take", he
    wrote. Ptui, I say now in response. In the month in between, I found
    time to read the lengthy article, and wondered if anybody else posting
    here had bothered to do the same.

    There are indeed two speed ranges for bicycle dynamic stability. Six
    year olds know this from observation; we all agree that slow speed is
    different. The context here, though, is countersteer. Sorry, Pete.
    Sherman wins that argument. The bicycle is unstable in the slow speed
    range, by definition. Countersteering to enter turns does not apply.

    I hope that this now restores the balance in the universe.
    MikeWhy, Apr 28, 2013
  14. Joe Mastroianni

    Twibil Guest

    Off your meds again, I see. Pity.

    (But...BUT... *BUT!* It *MUST* be true!

    He read it on the web!)
    Twibil, Apr 28, 2013
  15. Joe Mastroianni

    T0m $herman Guest

    Do you want people to hate you? ;)
    T0m $herman, May 4, 2013
  16. Joe Mastroianni


    Apr 13, 2016
    Likes Received:
    This thread got feisty! Sucks about the test.
    Twoloose, Apr 26, 2016
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