From: conrad@pico.OZ (Conrad Drake)
Newsgroups: rec.motorcycles
Subject: Re: Countersteering a shafty
Date: 28 Aug 92 03:20:06 GMT
Reply-To: conrad@pico.qpsx.oz.au
Organization: QPSX Communications
X-Newsreader: Tin 1.1 PL4

martin@adpgate.UUCP (Martin Golding) writes:
: randy@ninja.megatek.uucp (Randy Davis) writes:
: 
: >   First off, you HAVE to countersteer to turn ANY two-wheeled conveyance
: > when the two wheels are aligned in the same track.  
: 
: You are wrong. I have proven it. I am willing to prove it in your presence,
: on your motorcycle. Just give me a call before you fly it here.
: 
I have just spent quite some time playing in a very large car park (6
hours over 3 days) playing with turning.  The conclusions I and the
poerson who was with me came to are:

Weight distribution is about balance -> not dropping the bike. More
later.

You use your knees/thighs to lean the bike -> turning.   
   On this bike leaning the bike resulted in the front wheel turning
into the corner (try this at 0mph). Also at 20MPh this can be used to
slalom in & out of car bays.

You use your arms to a) limit movement of the front end in the previous
example and b) countersteer.  Which also causes the bike to turn.
(Which nobody can deny. For..)

I spent a lot of time going 'round & 'round in circles and figure-of=8s
at varying speeds and played with hanging off both the inside & outside
of the bike.  At, say 30mph I could hang off the inside & have the bike
almost upright OR sit bolt upright & scrape the footpegs.

However, at very low speeds I had to sit very upright, keep my inside
arm almost dead straight) and lean the bike right over.  Icecream-cone
devotees will rejoice in the knowledge that this involves a lot of
camber thrust.  The front wheel also pointed (very much) in the
direction of the turn (Ackermann effect I believe).

[ObMoto-rational - this whole experiment was a result of my apparent
inability to do right hand U turns (I was leaning myself in - had my arm
bent-> loss of balance)]

Also, at these low speeds my attempts to steer with the bars invariably
resulted in life-threatening (;-)) wobbles.  I had to use my knees.
However, as the speeds picked up, the effects of using my knees became
less adequate - at 40mph I needed quite a bit of bar-counter-steer
assistance to initiate the turn.

All of this was done on a well-worn CB400/4, (which needed a lot more
Bar effort than my old KR250).

Our conclusions are that:
countersteering and thigh-power lean the bike.
countersteering is no bloody good at low speeds.
thigh-power is of little use at high speeds (unless the front wheel is
off the ground, Kevin).

Ackermann, drift & camber thrust all influence whether a bike will
continue to turn.  You don't drift at 2mph & you don't roll-y-cone at
50mph.

How far you lean & how far your bike leans determain whether you will
fall off.  They also determine how much camber thrust is generated.

Well that's about it; One persons experiments.  Y'can agree, ignore or
flame to your heart's content.

Conrad Drake
--
"There's something stirring in my loins and it isn't the spirit of Jesus"
                - Helen Razor, JJJ announcer, 1992.

Email: conrad@pico.qpsx.oz.au
Snail: QPSX Communications, Private Bag 24, West Perth 6005, Australia. 
Numbers:(ph) +61 9 324 1641, (fx) +61 9 321 2984 (dod) 0604

Newsgroups: rec.motorcycles