[QUOTE=RugBug;7205115]
Yes…if only a horse were like a bicycle. But a bicycle cannot balance on its two wheels at a standstill. A horse can balance on its four legs just fine.
RAyers also pointed out that a cyclist CAN balance at a stop (track stand), however, it’s still not analogous.[/QUOTE]
But it is EASIER to stay upright when you are going faster.
Just because you/the horse/the bike CAN stay upright at slower speeds, it is still EASIER to balance at higher speeds.
[QUOTE=alterhorse;7204331]
Some of my thoughts about the concept of jumping position effecting bascule…
Speculatively, I think a riders jumping method, and body weight manipulation, may influence both ballistic trajectory, and behavioral factors, of jumping horses.
The first principle of this hypothesis is based on the concept that a forward shift in rider weight will move the center of gravity of the “horse/rider unit” slightly forwards in the takeoff phase of jumping.
The ballistic principles for propelling (thrust) an object (projectile) onto a calculated trajectory will require that the propelling force be in alignment with the center of gravity of the propelled object along the calculated path of the trajectory .
Movement of the center of gravity in the “horse/rider unit”, must therefore require a recalculation of the force trajectory to achieve alinement.
If my hypothesis is correct, then a riders body position during the take off phase of jumping must influence the horses body orientation relative to the path of the horse/rider flight trajectory arc.
This shifting of the center of gravity is a factor of physics. But I think it may also have a potential to influence a horse behaviorally
The degree of mathematically calculated influence over a horses center of gravity may only be small, but I think the horse must also mentally factor this influence into his behavior in order to choose a successful trajectory over a jump.
If the rider exposes a horse to unpredictable variations in a forward weight shifting jumping technique. I think that the horse may modify it’s bascule to encompass the variable of not being able to predict exactly how much weight shift to expect from the rider before any given jump.
The horse will then over compensate for that center of gravity shift that it cannot predict, by choosing a trajectory and a bascule that will provide the horse with the ability to cope with the entire range of rider weight shifts that the horse may potentially need to compensate for.
I also speculate that horses traveling at higher velocities will have a greater force of momentum that will diminish a riders ability to effect the horses center of gravity through the use of forward weight shifting.
I think that this effect might only be noticeable when a horse is jumping at a slower pace where the horse must produce the majority of it’s forward jumping thrust by primarily using it’s musculature, and not factoring any substantial component of pre-existing momentum into it’s jumping trajectory.[/QUOTE]
Oh for cryin’ out loud…why on earth couldn’t you just say “you jump ahead your ass generally lands on the ground”! 
[QUOTE=meupatdoes;7205108]
So basically, for less advanced/balanced [bike] riders, maintaining momentum aides the [bike] rider until they can better control their center of mass and gravity? But when they get more advanced, physics is different?
Personally I have never seen a cyclist stop at a light with both feet on the pedals. Everyone I have ever seen, bike and motorcycle alike, has had one foot down.[/QUOTE]
A track stand is almost impossible on a motorcycle, unless it is a very light one. The rider simply does not have enough mass/influence to overcome the motorcycle’s. I can do it on my scooter, but it’s not easy.
ETA:
Consulted a PhD in Astrophysics on the question and the response was:
"any troglodtye can stay upright at speed, but you have to be f*cking amazing to do it at rest
aka angular momentum conservation"
Did you ask your physicist if you can compare the balance of a two wheeled bicycle with that of a four legged horse? It’s a ridiculous comparison. :rolleyes:
Right, so you need to marshall speed to your side to be able to overcome that issue on a motorcycle. You are physically incapable of balancing a heavy motorcycle with your own mass unless speed is giving you a helping hand.
This disproves my theory that speed helps maintain balance how?
[QUOTE=RugBug;7205151]
Did you ask your physicist if you can compare the balance of a two wheeled bicycle with that of a four legged horse? It’s a ridiculous comparison. :rolleyes:[/QUOTE]
Oh, so gravity applies to bikes but not horses then.
And birds have two wings so they have completely different rules.
[QUOTE=meupatdoes;7205161]
Right, so you need to marshall speed to your side to be able to overcome that issue on a motorcycle. You are physically incapable of balancing a heavy motorcycle with your own mass unless speed is giving you a helping hand.
This disproves my theory that speed helps maintain balance how?
Oh, so gravity applies to bikes but not horses then.
And birds have two wings so they have completely different rules.[/QUOTE]
Maybe you need a refresher course in physics. Or heck, go find a bike, and try to make it stand up on its own. I can’t believe you are even trying to argue this. Kickstands were invented for a reason. Sheesh.
[QUOTE=RugBug;7205169]
Maybe you need a refresher course in physics. Or heck, go find a bike, and try to make it stand up on its own. I can’t believe you are even trying to argue this. Kickstands were invented for a reason. Sheesh.[/QUOTE]
Read that again and see whether or not you think that the need for a kickstand at rest (but not in motion) supports or detracts from my argument that speed helps a body in motion stay upright.
Probably I could get a bike to stay upright on its own if I pointed it down a hill and let it wheel itself down, AT A SUFFICIENT RATE OF SPEED.
This thread now has everything from philosophy, ancient world history, english, logic and now, physics!
Who needs University when you have COTH.
[QUOTE=meupatdoes;7205108]
Personally I have never seen a cyclist stop at a light with both feet on the pedals. Everyone I have ever seen, bike and motorcycle alike, has had one foot down.[/QUOTE]
You obviously don’t live in an area with lots of cyclists. Here is the official wikipedia reference (as RugBug notes): http://en.wikipedia.org/wiki/Track_stand
Here is a nice introduction to the kinetmatics of jumping:
http://www.youtube.com/watch?v=NuirTT9S2iM
Goodlife,
You hit the the most important concept, “…as they have not yet learned that collection comes from the seat and leg (or, as you put it, they don’t yet understand where their center of gravity is).”
I was commenting directly to meupatdoes’ statement that a bicycle has to be moving to stay up right with a rider, which is false. The ability to stay upright is a function of where both the center of gravity and center of mass are located. If they are aligned in the system, they can stay upright indefinitely.
I understand your thoughts on this, however, consider the old adage that a horse needs only 1 stride to jump 5 feet. Thus, naturally, a horse needs no speed to attain height. Rather forward momentum is necessary to jump across a fence. (e.g. watch deer, elk, moose jump over pasture fences - they do it from a walk). This is also verified by Clayton’s work: Linear Kinematics of Water Jumping in Olympic Show Jumpers. They showed significant effect of the center of gravity to the ability of the horse to jump up and over.
This is also borne out by work by Lewzcuk et al., (2006), Repeatability of the horse’s jumping parameters with and without the rider. They show that a rider can significantly affect the repeatability of a horse to meet and jump a fence.
[QUOTE=meupatdoes;7205173]
Read that again and see whether or not you think that the need for a kickstand at rest (but not in motion) supports or detracts from my argument that speed helps a body in motion stay upright.
Probably I could get a bike to stay upright on its own if I pointed it down a hill and let it wheel itself down, AT A SUFFICIENT RATE OF SPEED.[/QUOTE]
Your comparison is absolutely apples to oranges. Maybe you should compare a car and a horse.
Does speed affect balance? Yes. But you have to take into account the system you are discussing.
[QUOTE=RAyers;7205186]
I was commenting directly to meupatdoes’ statement that a bicycle has to be moving to stay up right with a rider, which is false. The ability to stay upright is a function of where both the center of gravity and center of mass are located. If they are aligned in the system, they can stay upright indefinitely.
.[/QUOTE]
My argument all along has been that increased speed makes it easiER to balance.
Just because it is POSSIBLE for a few people who practice a lot to balance on a motionless bike does not mean it still isn’t easiER to stay upright on a bike that is in motion.
See eg:
riderless bike in a garage? needs a kickstand.
riderless bike wheeling down hill? stays upright until it runs out of hill.
[QUOTE=RugBug;7205187]
Your comparison is absolutely apples to oranges. Maybe you should compare a car and a horse.
Does speed affect balance? Yes. But you have to take into account the system you are discussing.[/QUOTE]
The system is physics as a whole.
The system does not apply differently just because you have two legs, one eye, blond hair, or four legs.
Yes, an object with a wider base of support (ie a horse) will have an easier time balancing than an object with a narrower base of support (ie, a racing bike). But both the horse and the racing bike will still, within the system, have an easiER time balancing at higher speeds.
Don’t let your personal issues with me cause you to take on physics.
Physics really does not give a f*ck.
crap I hated physics in school …and now it’s shown up in a hunter thread…crap…:lol:
[QUOTE=meupatdoes;7205203]
My argument all along has been that increased speed makes it easiER to balance.
Just because it is POSSIBLE for a few people who practice a lot to balance on a motionless bike does not mean it still isn’t easiER to stay upright on a bike that is in motion.
See eg:
riderless bike in a garage? needs a kickstand.
riderless bike wheeling down hill? stays upright until it runs out of hill.[/QUOTE]
So is it easier for a horse to balance at the full gallop? Is it easier for you to balance when you run as fast as you can? So, beginner riders should GALLOP fences?
The reason this part of the conversation started is the necessity of understanding how the centers of mass and gravity affect a horse’s ability to clear a fence. Hands on a neck change the rider’s CG (not CM) relative to the horse’s CM thus creating a new moment that alters the ballistic trajectory (bascule). But this only works if the rider places a significant fraction of their weight onto their hands.
This is where you are missing the fundamentals of statics and dynamics. It is not speed. On a bike or motorcycle it is the gyroscopic motion of the wheels. If we made the mass of the outer rims even heavier, we could slow the speed down to almost zero, theoretically. Hence why your comments on this subject matter are apples to pomegranates.
I spent almost a decade calculating CMs and CGs for heavy lift vehicles and orbital trajectories. Never had to include speed to figure out how to balance 2 million pounds on 32 square inches of launch heads.
[QUOTE=meupatdoes;7205203]
My argument all along has been that increased speed makes it easiER to balance.
Just because it is POSSIBLE for a few people who practice a lot to balance on a motionless bike does not mean it still isn’t easiER to stay upright on a bike that is in motion.
See eg:
riderless bike in a garage? needs a kickstand.
riderless bike wheeling down hill? stays upright until it runs out of hill.[/QUOTE]
You are trying to use a very simple concept to explain complex forces. If you could make a perfect system devoid of any external forces (bike has a fixed front wheel (no ability to turn the front wheel from the plane of the bicycle itself) the front wheel is true round, the street is even with no deviations (external forces that would change the path of the bike), no wind, and the force exerted was in line with that of the road/hill, etc) then the bike would probably roll until it ran out of hill. That’s a LOT of variables that have to be accounted for.
[QUOTE=RAyers;7205244]
So is it easier for a horse to balance at the full gallop? Is it easier for you to balance when you run as fast as you can? So, beginner riders should GALLOP fences?[/QUOTE]
The overall balance/speed rule for An Object In Motion is the same.
Whether additional forces come into play, such as the mechanics of self propulsion and acceleration, is another question entirely.
Maybe you should try calculating how to get a top to stand up straight without spinning it.
[QUOTE=meupatdoes;7205209]
Don’t let your personal issues with me cause you to take on physics.
Physics really does not give a f*ck.[/QUOTE]
I’m not taking on physics, but rather your rudimentary understanding of physics…which seems to be even worse than mine. I’m also taking on your ability to change a topic to whatever you want it to be by making false comparisons.
Don’t let your desire to f*ck with people on the internet and make yourself feel superior, 'cause you to make sh#t up. You can’t boil all physics down to one simple statement.
[QUOTE=RugBug;7205272]
I’m not taking on physics, but rather your rudimentary understanding of physics…which seems to be even worse than mine. I’m also taking on your ability to change a topic to whatever you want it to be by making false comparisons.
Don’t let your desire to f*ck with people on the internet and make yourself feel superior, 'cause you to make sh#t up. You can’t boil all physics down to one simple statement.[/QUOTE]
You are the one making false comparisons.
Just because several laws of physics will apply to one situation (gravity, for example, is keeping the horse on the ground even while speed is playing a role in balance) does not make one part of the equation untrue or change one of the rules.
This thread is hilarious. I advise everyone to stick to their day jobs, only one of whom’s appears to be science.
[QUOTE=meupatdoes;7205270]
The overall balance/speed rule for An Object In Motion is the same.
Whether additional forces come into play, such as the mechanics of self propulsion and acceleration, is another question entirely.
Maybe you should try calculating how to get a top to stand up straight without spinning it.[/QUOTE]
I am sorry, but now you really are showing how little you understand Newtonian physics. The only reasons tops need to spin is the manufacturing defects the result in that CG being off center from the CM. It is VERY easy to show that a top does not need to spin if CG and CM are exactly aligned. A real world example are railroad turn tables. TONS of steel balanced on a pin bearing such that a single person can move it with a locomotive on top if it by hand.
Your first statement is true and is Newton’s First Law.
So once again we are back at speed overcoming problems in the equilibrium to keep the poorly designed top upright anyway. If the top is perfect, it doesn’t need speed. If the top is imperfect, speed will make up the difference and help it balance.
Yep, really disproved my point again there.
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