Conference vmszoo::rc

    I saw one earlier this spring being put through it's paces by a
    model shop in Tokyo, Japan.  I think it was a repli-racer looking
    Honda.  Anyway, the bike scooted around rather well.  It was quick
    and could turn sharply.  It leaned (and scraped) realistically
    and would drag the wire stabilizer bars on each side of the bike.
    
    Like the cars, there's apparently a number of parts you can replace
    with better ones that upgrade the bikes performance and stability.
    Shocks, of course, are good candidates for replacements.  There
    were a few other items that I was told about.  I think you can replace
    the rear sprocket.  The chain really was impressive.  In fact the
    machining and detail were amazing--the usual Japanese fare.  I don't
    know anything about the radio.  Just a two-channel unit, but it
    looked like a pretty custom set-up due to the cramped space and
    tiny servos.

    
    I know the biggest upgrade for any r/c car/motorcycle would be
    ball bearings replacing the bushing...
    
    Did you find out how they turn ...
    
                          Tom m

    I remember seeing some R/C bikes here in the UK quite a few years
    ago but I can't remember who made/supplied them. I think there was
    even a moto-crosser with an i/c engine at one time but I can't be
    certain. As far as I know these little beggers used standard R/C
    sets but I have lost cantact with a guy I knew who had one of the
    electric 'street racer' versions. Next time I go home I'll try and
    dig out the old mags. and see if I can find anything.
    	They were funny little beasts and took quite a bit of skill
    to guide them round any sort of circuit and with no stabalizer bars
    you had to keep them moving or the just fell over. Great fun if
    you get a few together for a grand prix!!
    
    Ken Lee (Reading UK)
    

    Re - .2,
    
    They turned just like the 'real thing'.  Both servos were inside
    the tank/engine unit and the steering servo was coupled to the 
    steering head.  Seemed like they were, indeed, tippy at slow speed.
    But once you got them going, they were more stable.  Even if the
    bike fell over, though, you didn't have to pick it up to right the
    bike.  An application of power and appropriate steering input would
    cause the bike to jump back off of the stabilizer bar and motor
    on its way  As I recall, the bikes were about 10 inches long and
    looked pretty realistic.
                           
    reb

    These bikes bring up an interesting point. You indicated that they
    were tipsy at slow speeds but smooth out at higher speeds. Unless
    there is a mixing circuit in the TX or RX I expect that they turn
    like the big boys at high speeds but not so at a crawl. Here's why.
    
    I bike at slow speeds, where the rider balances the unbit is turned
    by deflection the front tire towards the direction that the rider
    wishes to go. IE, right for right turn...
    
    At higher speeds where there is a gryoscopic effect the front tire
    is actually deflected in the opposite directing from where the rider
    wishes to travel. IE, Front wheel points left;bike turns right.
    What happens is that as the bike is traveling forward the wheel
    is deflected in the opposite direction of the turn and the bike
    "falls" over in the direction of the desired turn,the wheel returns
    to a somewhat neutral condition. To tighten the turn the deflection
    is held longer or more severe.
    
    Tom

    Tom,
    
    I'm not a dyed-in-the-wool 'scooter monkey,' but I've ridden enough
    over the years to say that I've never been conciously aware of turning
    the wheel left to go right and vice-versa as you suggest.  What
    I _am_ aware of is that, at high speeds, the turn is accomplished
    by leaning, shifting the center of gravity in the diretion you desire
    to turn; lean right, turn right...lean left, turn left.
    
    Theoretically, this may accomplish what you describe; since the
    wheel is held straight ahead, you might say that it is actually
    opposite the direction of the turn, in either direction.  I guarantee
    if you tell a novice to make high speed turns by turning the wheel
    opposite to the desired direction of the turn, you'll be out there
    scopping him up in a dust-pan!      

      |
      | |      00	 Adios,      Al
    |_|_|      ( >o
      |    Z__(O_\_	(The Desert Rat)

        Re:< Note 732.6 by PNO::CASEYA "THE DESERT RAT (I-RC-AV8)" >

                When I went to university one of my fellow students wrote
        a thesis on  this  subject.    He actually tested the theory that
        high speed turns are  made  by  turning  the wheel in the "wrong"
        direction  by driving at high  speed  with  hands  off  and  just
        pushing the handlebar on one side.  The result of his study was -
        no, not a bad accident - but  that it indeed is true.  You cannot
        turn a motorbike at high speed by leaning with your hands off the
        handlebar, and you do indeed push the "wrong" way.  Somehow it is
        learned unconciously by all bikers.  Bycycles can be driven hands
        off because it's done at low speed.
        
        Anker

>        no, not a bad accident - but  that it indeed is true.  You cannot
>        turn a motorbike at high speed by leaning with your hands off the
>        handlebar, and you do indeed push the "wrong" way.  Somehow it is

I can.  But I will admit that we may not agree on what HIGH speed is.
Up to about 75 MPH I have turned by leaning.  Your right that pushing
the handle bar will make the bike lean in the opposite direction.
Cause it tries to take the front to the left and therefore leans the
bike to the right.  I figure the lean causes you to ride on the inside of the
round bottom tire cutting a shorter circle to the inside.

In other words you can tighten up the yoke and steer solely by leaning.
In fact I think everybody does.  If you imagine the extreme case.
Imagine your zipping along at 60 MPH and you yank the handle bars to turn
the front tire to the left as far as they will go.  As you fly over the 
handle bars you will be on the right side of the bike and it will be 
leaning (crashing) on its right side.

Anyway aside from details I think we all agree.

Bye          --+--
Kay R. Fisher  |
---------------O---------------
================================================================================

    As Anker said, this must be a conditioned reflex, learned unconciously
    as, like I said earlier, I've _NEVER_ been aware of conciously turning
    the wheel opposite of the direction I wish to turn.  
    
    I saw an R/C motorcycle demoed at the old Tucson Winternats many
    years back.  I think it was imported by Kraft (or Kraft was toying
    with the idea).  I don't recall how the steering worked but it almost
    seems like I remember that the wheel could be turned for low-speed
    turns _and_ the driver figure's body could be leaned for turns at high
    speed.  Sure would be interesting to hear from someone who's ever
    run one of these R/C bikes so the steering could be clarified.

      |
      | |      00	 Adios,      Al
    |_|_|      ( >o
      |    Z__(O_\_	(The Desert Rat)

    
    re: last few.
    	The effect that you have been talking about is called "counter-
    	steering". At speeds above 30 mph or so, this is how a motorcycle
    	is turned. Most people think that they are turning the bike
    	by leaning but are actually counter-steering unconciously to get 
    	the bike to turn and lean, and then releasing pressure on the
    	handlebar and leaning to keep the bike in the turn. When you want
    	to come out of the turn, you counter-steer in the opposite
        direction until you are straight, release pressure on the
    	handlebar and sit up straight. The next time you're out riding,
    	try it, you'll be amazed (but please do it carefully). The faster
    	you go, the more pronounced it is. I have been riding and racing
    	motorcycles for the past 15 years and can attest to this. I
    	hope this long-winded explanation helps.
    				
    						Jim
     
                  
                  

    When a rider thinks that he/she is leaning and making the bike turn
    in reality the shifting of weight induces a greater pressure on
    one side of the handlebar than the other. This then turns the
    handlebar ever so slightly and makes the bike fall in the opposite
    direction. 
    
    
    Tom

    I can't recall exactly how the steering/counter-steering was achieved
    on the ones I saw several years ago, but I do remember that there
    was no direct 'handle-bar' control. In fact there was no handle-bar
    at all and the front wheel/yoke was completely free (not even spring
    centered) to wobble in whatever direction was required. The more
    I think about it, I have the idea that steering was via a 'vertical'
    turning of the yoke, tilting the base of the forks out to the right
    to induce a left turn. This would support the counter-steering
    principle.
    	I don't recall stabaliser wires being attached to the machines
    I saw but this may have been the constructers own idea. His bikes
    always had to be picked up when they feel over!
    	The electric bikes (the ones I saw) were indeed about 10"-12"
    long but I think there was a 1/4 scale Yamaha moto-cross beast
    available which used REAL power (.15 to .19 I think). I never saw
    one 'in the flesh' but it must've been quite a beast!
    
    Ken Lee

    I too ride a bike, (650 Honda) and never realized this idea of
    counter-steering until my older brother mentioned it.  Since then
    I've purposely tried it......and it works!  I head down the road
    at better than 30mph and as I approach a bend in the road, (for
    demo sake its a LEFT turn) I PUSH on the LEFT hand grip or PULL
    on the RIGHT hand grip and the bike commences to turn left.  I
    was amazed!  The one  thing I noticed was it makes turning alot
    easier (smoother) applying this concept.
    
    Ken

<    as I approach a bend in the road, (for
<    demo sake its a LEFT turn) I PUSH on the LEFT hand grip or PULL
<    on the RIGHT hand grip and the bike commences to turn left.  

If I remember my "right-hand rule" correctly, that's a result of gyroscopic 
precession. Remember Mr. Wizards' demonstration where somebody stands on a 
turntable while holding the axle of a spinning, weighted bicycle wheel? As the 
wheel is tipped on its' side, the guy holding it starts to rotate on the 
turntable. Steering to the right in the above example will cause the bike to 
lean to the left, thus initiating the turn.

Dave

    So by all of the conversation that is taking place,I take
    it that no one has seen how they actually have these things turning
    or if you can use some other type of speed control and receiver...
    
                                     thanks the same..
                    

< Note 732.8 by K::FISHER "There's a whale in the groove!" >

<	Your right that pushing
<	the handle bar will make the bike lean in the opposite direction.

Thinking more about this, I think Kay also has the right answer. By "counter
steering, you effectively "yank" the bottom of the bike out from under you, thus
inducing a lean in the opposite direction. Once you're leaning at the desired
angle, it's simply a matter of "balancing" your center of support beneath your
center of gravity (keeping in mind that, in a turn, "gravity" is composed of the
normal gravitational force combined with the centrifugal force). To right
yourself from a left turn/bank, steer more to the left. That yanks your center
of support more to the left, more into line with your CG, thus eliminating the
bank. I still think that there is an element of gyroscopic action as well. 

Dave 

    RE the counter steering debate, I think it's reasonable to say that
    you use the counter steering technique for 'high' speeds and/or
    extremely fast reaction or panic turns, but it's not required
    to turn a bike.  The key seems to be weight/CG shift to quickly
    destabilize the bike to overcome the gyroscopic effect.  
    
    I have an old BMW (R500/2) with the Earles forks.  The bike is so 
    stable that I can ride and turn it around shallow to moderate curves 
    without touching the handlebars.  I just move my butt around and lean 
    into the direction I want to turn.  I have noticed, however, that to 
    overcome the gyroscopic effect I end up "pushing" (as somebody said) 
    with my butt rather dramatically to get the bike out of it's stable 
    condition. I end up wiggling a bit, then leaning to get the bank angle 
    I want.  Anyway, the point is that bikes do turn without countersteering, 
    but counter-steering serves to destabilize the bike and turn quickly 
    without having to lean so much.  
                    
    I'm also a pilot and I can say that the bike situation seems similar 
    as 'kicking in the rudder' into the direction of the turn desired 
    before bringing in aileron input.  Or like when you really kick in 
    opposite rudder before a steep/G bank (especially on a high wing,
    high dihedral aircraft).  This effect was especially apparent on 
    gliders and jets, where you didn't have the torque and 'P' factor 
    helping you out (or working against you) and needed a kick to knock 
    the aircraft out of its equilibrium state.  Failure to kick in enough 
    rudder in turns, of course, results in a slider or mushing/uncordinated
    turn. 
                
    So much for my 2 cents.  Back to the RC motorcycle.  Indeed, at
    slow speeds the bike didn't turn like the big boys.  It leaned over
    way too far for the speed (hence the stabilizer bars) it was going
    and had a very tight turning radius to the point where it laid on 
    it's side.  Then as it was given more throttle it spun around and 
    was steered/straightened out to the direction desired.  As steering
    inputs were given at 'speed', the bike leaned left or right and
    acted more realistically.  BTW, if the bike was turned to sharp
    at slow speeds it would slide on it's side and do something like
    doughnuts until it righted itself.  The RC transmitter was a standard
    pistol grip kind.
    
    By the way, my name is Rodger Burkley and I haven't been in this
    conference for a long time, but enjoy RC flying very much.  More
    fun than the real thing!!  (at least more relaxing)  But, alas,
    I've been unable to get back in the air on a regular basis for
    some time for a number of personal/professional reasons.  Hopefully,
    that will change..               
    
    Rodger   

    I'll add my final comments to this note.
    
    To those that think that they can turn a bike with only a cg shift
    I say, go out and weld the yoke of the bike solid and then try it.
    Oh let me say now that it was nice noting with you. 
    The yoke os a hinge. and pressure on the bars or shift of cg will
    enact an angular difference in the yoke. The yoke will turn in the
    opposite direction of the cg shift or pressure on the bars. Hence
    the counter stearing. 
    
    Bye,
    
    Tom

>    I say, go out and weld the yoke of the bike solid and then try it.

I know - at my age the mind is the second thing to go.  Maybe I'm crazy
but I seem to remember there was this big knob on the yoke that I used
to tighten up when cruising (solid as I could manage - not welded but
logically the same thing).  Don't all bikes have a knob to tighten the
yoke up?  Was this all a dream?

I used to drive a friends scooter all over with out touching the 
handle bars.  Course it had to knob to make them tight.

In fact (rambling warning) one time (I was about 13 years old) I was on
highway 10 and I was trying to get all the way downtown and back to my 
friends house without touching the handle bars.  I knew the railroad
tracks would be a challenge cause they always put the steering into 
an oscillation and I had to grab the handle bars to stop it.  The tracks
came in a pair with a short distance between (maybe 30 feet).  So as I
approached the first set of tracks I was determined not to touch the
handle bars.  Bumpty Bump and sure enough the handle bars were in
oscillation but I figured - what the heck - the next set of tracks
will straighten them out.  Bumpty Bump and I went over the front of 
the scooter and skinned up my hands good.  Then this highway patrol car
pulls up along side and informed me that they had followed me in from
the highway.  "Well boy - did you learn your lesson?"  "Yes sir" hands
stinging and bleeding and feeling pretty stupid - not for crashing so
much as not seeing the guy following me.

Bye          --+--
Kay R. Fisher  |
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================================================================================

    gee guys, thanks for all the info on rc motorcycles....... ;^)
    
    Brian

    
     the front wheel pivots all on its own,there is a weight (flywheel)
    inside the front wheel that keeps it vertical. The streeing servo
    inside the motorcycle tilts the body against the stationary front
    wheel which causes the bike to fall in the direction of the turn.
    
    
    I just bought one from kyosho..honda rs500 (rothman's honda)..
    cant wait for more people to get them so we can race....
    

    Where are you located ?  I'd LOVE to see it and just might
    get convinced to buy one, too!
    
    					Roger (in Marlboro)
    

    
       Roger..I'm in Colorado Springs,Colo..
    
    
     I frist saw it in Tower Hobby catalog,so I went to Denver and hit
    just about all of the hobby stores until I found one that had a
    working unit, I was hooked...$200 for a complete kit (motorcycle,radio,
    battery and charger)...I just finshed the assembly and in the process
    of painting it...   
    
                                       Tom m

    
    
    Tom,
    
    Well, I guess I won't be dropping by at lunch!!  Let us know
    what you think of it when you get it running.
    
    				Roger