Harley Davidson Forums banner

1 - 20 of 43 Posts

·
Registered
Joined
·
39,451 Posts
Very impressive.
 

·
Just passing thru
Joined
·
6,636 Posts
Great! I have the opportunity to watch my local county police train and qualify right across the street from my job.Always a treat. Did anyone notice the art of counterbalancing. At those speeds you lean away from the turn. It took me a while to learn that and also the use of the clutch as your gas pedal. I need a tad more practice to catch up to that guy.
 

·
On a ride
Joined
·
4,996 Posts
Discussion Starter #6
Great! I have the opportunity to watch my local county police train and qualify right across the street from my job.Always a treat. Did anyone notice the art of counterbalancing. At those speeds you lean away from the turn. It took me a while to learn that and also the use of the clutch as your gas pedal. I need a tad more practice to catch up to that guy.

EZE... That is indeed the technique for very tight crurves... leaning away from the inside. Easier to say than do it! Was thinking the same as well... the displayed sensitive touch with the clutch and throttle.
 

·
Mod Extraordinaire
Joined
·
1,980 Posts
When I was taking my MSF Course, I found it WAY easier to do those types of maneuvers in 2nd gear.

If I tried that on my V-Rod, there'd be no cones left standing!
 

·
Just passing thru
Joined
·
6,636 Posts
Maybe someone can verify this fact. I was speaking of the video that Steve posted to a friend and they told me that cop Harleys have some sort of gyroscope in or on the motor enabling them to balance better at very low speeds, Parade duty and funeral processions and the like. Sounds feasible but I have never heard of this. Has anyone else?
 

·
Registered
Joined
·
39,451 Posts
Yeah, Ive heard of a gyroscope in the motors.... but they are not exclusive to only cop bikes, infact all of our bikes have them.... Its called a flywheel! :D
Increase your RPMs, the more stabilization from the gyroscopic effect it gives you.

Its kinda like when you are going down the highway and lock your throttle, when you take your hands off the handlebars you still go straight. Do the same thing when stopped and the motor off, the bike falls over.
 

·
On a ride
Joined
·
4,996 Posts
Discussion Starter #11
Good thoughts Kainam. Had never head of a gyroscope on a bike and never thought of the flywheel as being one. I wonder if the weight of a flywheel as any effect.
 

·
Registered
Joined
·
39,451 Posts
Good thoughts Kainam. Had never head of a gyroscope on a bike and never thought of the flywheel as being one. I wonder if the weight of a flywheel as any effect.
I believe it would, or more specifically the distance from center in which the mass distribution lies....

*Simplified equations*
Gyroscopic Inertia (I) = Mass * (radius^2) / 2

Gyroscopic Force = Mass * radius^2 * RPM^2 * pi^2

where radius = the average distance from center in which the mass distribution lies.

So, although mass does have an effect on the gyroscopic force, the primary factors are RPM and radius of the flywheels.

http://www.gyroscopes.org/math.asp
web page to play with the numbers

 

·
STAND AND FIGHT!
Joined
·
13,175 Posts
I don't know where you guys are seeing a flywheel on a multi-plate motorcycle clutch.
If you were looking for possible gyro forces in the engine or drivetrain,
the crankshaft with it's balancer assembly would be the place to look.
But if you think about it you'll decide that there isn't any gyro effect there.

If there were any significant gyro forces in the motor, you would know it,
because there would be significant forces you could feel at low speeds
directly related to rpm.

If you try to balance your bike when it is sitting still with no feet,
is it significantly easier to stay upright if the motor is revved up
than when the motor is off? I think not.

There is real and significant gyroscope effect on any motorcycle,
it is the combined spinning mass of the wheels and tires.
Nothing in the motor keeps it stable at speed, it's the wheels.

The significant factors in any gyro effect are radius, (more is better,)
weight near the edge, (more is better,) and rpm, (more is better.)
Easy to see where the wheels and tires rate high in this formula,
the radius is very high and the mass at the edge is high.

Can't say I know for sure, but I'm 99.99 percent there is nothing on a police bike
any different than your bike. And any force that would make a bike more "stable"
in a parking lot cones course, would wrestle negatively with the rider on the road.

This particular story sounds like a real existing effect that has been misunderstood
and re-told incorrectly.

At a high speed, the higher the better, take your hands off the handlebars
and thump one end pretty hard with the palm of your hand. Tentatively at first,
since while the gyro effect will easily correct for the bump, if you're scared to death
you could mess up some other way.

I saw this demonstrated on a How Does it Work show, they were filming out the open side door of a van,
a guy at 85 mph on a heavy dresser, so he's got big heavy wheels, he leaned back with no hands and thumped
the end of one handlebar hard, with a blow that would knock you down if he was hitting you on your nose
with the same force. The front end shuddered for about 1 second and settled back down to perfectly stable,
and it was quick about it. He had added a lot of off kilter force, the gyro effect with even more force quickly snuffed it out.
 

·
Mod Extraordinaire
Joined
·
1,980 Posts
Yup, any gyroscopic effect is going to come from the wheels. If there were some sort of a lateral gyroscope in the bike, then the bike would be more difficult to maneuver one way than the other... I would think. I don't think there's anything different with cops' bikes.
 

·
Registered
Joined
·
39,451 Posts
Who said anything about a flywheel on a multiplate clutch? :confused:
 

·
Registered
Joined
·
39,451 Posts
I guess you guys have never seen a "slow race"? The wheels aren't turning very fast on one of those.

Then you also have trials bikes.... the wheels dont normally turn very fast on those either, and yes, they do balance those bikes standing still.

http://www.youtube.com/watch?v=Iz9d80ynux8
 

·
STAND AND FIGHT!
Joined
·
13,175 Posts
..yes, they do balance those bikes standing still.
And they could do it with the engine off just as well.

Just cause they have balance doesn't mean they have gyro effect,
Does a uni-cycle rider have any gyro effect?

Imagine how easy it would be to balance you bike with the engine off,
and rolling down a long but very gentle slope. Walking speed at best.
The stability wouldn't be from any gyro effect, it would be from
the ability to steer and counter being momentarily off balance.
If the motor was in neutral and revving I don't think you'd be any more stable.

Correction, make that I don't think you'd be significantly more stable,
Agreed, there would almost have to be some effect.
I just don't think you could feel it, or we all would have.
 

·
Registered
Joined
·
212 Posts
I can do most of those exercises,just not at that speed,But I practice those exercises every week.My 07 RKC is all I us,no special gyro or balancing act.It takes a lot of practicing to do those,if you google motorcops and look at the rodeos you will see the varying skill level.Practice,Practice,Practice.
 
1 - 20 of 43 Posts
Top