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So I’ve heard people say that you can help prevent wheel spin by weighting the outside foot peg. There has to be something to this because I’ve heard it from several people, but what I don’t get is how you can put any weight on the outside peg when you’re hanging off the other side of the bike? I mean you would have to actually move your whole body towards the outside of the bike to put more weight on that peg. You could put more pressure on the peg without moving but how would that help stop wheel spin?
 

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Hey stuman, how's it going. The claim is based on a simple lack of understanding the physics involved. I don't have to tell you that some very top level riders really have no idea how or why things work like they do, but they sure as hell can make the bike go where they want when they want it to, and sometimes repeat a lot of myths in the telling.

http://www.r1-forum.com/forums/showthread.php?threadid=132439
 

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likebikes said:
So what you are saying is that you can weight the peg as you stand the bike up and come back on the seat?
You can progressively weight a peg as your mass moves over it. It doesn't mean that you will, but that you can. You cannot substantially weight a peg that your mass is not over.
 

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Why excatly does you're mass have to be over an object to "weigh it down" which I read as "exert a force upon". If you are leaning and you're ass is off the seat then all of your body's force resulting from gravitational pull and inertia will be transmitted to the bike through the foot pegs and handle bars. With most of the force being at the footpegs. I don't see why you couldn't bias the force on one peg if you wanted.
 

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Redlinger, can you elaborate how you can substantially weight a peg that your mass is not over? Also, where is the seat, and the tank, in your above equation? How does that fit in, and how much force is transmitted throught those points of contact? Are you transmitting a large amount of vertical force into the bars? What about the outside peg?
 

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The same way that water in a bucket will press against the bottom of the bucket when spun horizontaly. Despite the fact that the water is not directly on top of the bucket bottom it still exerts a force on it. When you change the direction that a mass is moving the mass resists this change that's called inertia. When you turn the motorcycle the motorcycle's mass wants to keep going in it's original direction. However the friction between the the road and you're tire's contact patch is great enough to force the motorcycle to change direction despite it's inertia. Your body is traveling at the same speed as your motorcycle and it also resists this change in direction. The points through which this force is transfered happen to be the parts of your body in contact with the bike. Most of the force is transfered through you're legs because they are capable of producing enough force to maintain an ideal riding position while cornering.

By using my legs I take most of the weight off the seat and I don't rest my torso on the tank while cornering so very little force is being transfered through those points of contact.

Out of curiosity have you ever heard of vector diagrams?
 

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Yes, I use them freqently. The vertical force vector that can be applied to the pegs decreases as the rider mass shifts laterally, and the lateral force vector increases. Hence, less ability ti weight the peg with increased lean angles. What about the handle bars? You mentioned them in your first post, but not in the subsequent one.
 

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The handle bar's are not designed to support the weight of the rider, they are used to steer the motorcycle.

Besides that point of all this was you claimed it wasn't possible to "weigh down the pegs". Clearly I have demonstarated that you can exert a greater force on the outer peg then the inner peg if you so choose, and since that is what people mean when they say "weigh down the pegs" any futher discussion seems to be nothing more then a irrelevant debate over semantics.

Besides the vertical component can be supported on the pegs, however it requires that you have enough strenght in you legs and enough friction between your boot and the peg.
 

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Redlinger said:
The handle bar's are not designed to support the weight of the rider, they are used to steer the motorcycle.

Besides that point of all this was you claimed it wasn't possible to "weigh down the pegs". Clearly I have demonstarated that you can exert a greater force on the outer peg then the inner peg if you so choose, and since that is what people mean when they say "weigh down the pegs" any futher discussion seems to be nothing more then a irrelevant debate over semantics.

Besides the vertical component can be supported on the pegs, however it requires that you have enough strenght in you legs and enough friction between your boot and the peg.
What I said was: "You can progressively weight a peg as your mass moves over it. It doesn't mean that you will, but that you can. You cannot substantially weight a peg that your mass is not over.".

But getting back to my question, you said, "If you are leaning and you're ass is off the seat then all of your body's force resulting from gravitational pull and inertia will be transmitted to the bike through the foot pegs and handle bars".

You seem to be retracting this statement now, or at least distancing your self from it (especially in so far as the bars are concerned) by claiming semantics, and unsuccessfully impugning my familiarity with vector forces.
 

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I'm sorry but you are mistaken about the requirement for you're mass to be over the pegs for you to use them to support the force produced by gravity. I have no idea how you could even belive this to be true. The force you exert on you're motorcycle due to gravity's pull, the vertical vector if you prefer, can be supported by the pegs. If your legs are sufficently rigid and you have sufficent friction between your peg and your boot then you can transfer the vertical load to the pegs.

If you want a real life example go to a fairly narrow hallway and climb up to the ceiling. Use your legs to press against the walls and walk up the wall. According to you I shouldn't be able to do this, but I can even though my mass isn't over the points of contact at all.

I haven't mentioned th handle bars much because they are irrelevant to this discussion. I only mentioned them because they are possible points of support, though the vast majority of support is through the pegs as I mentioned earlier. Additioinaly Stuman's question was about pegs not handlebars. Out of curiosity how much of you're weight do you support with you're handle bars while cornering?
 

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Where's my popcorn?
 

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Stuman from what I understand the purpose of pressing on the outside peg is to stablize you weight, and to make sure you use you're legs to move and support you're body. Both Keith Code and Kevin Schwantz teach you to weigh down the outside peg.
 

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IIRC Keith Code calls it pivot steering. Basically, as you are pushing your body to the inside and the inner clip-on, you push off with the outside leg. Yes, you're putting the weight at a greater height than it would be at if you weighted the inside peg, but the advantage of being able to quickly and efficiently lean the bike over outweighs that concern. Once you are finished changing the bike's position, I imagine that you would be best off weighting the inside peg as it is lower. Plus, you would be in position to move the bike the other way.
 

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It boils down to having your bike at a lower lean angle by having more weight further inside the turn. With a lower angle, the tire contacts the road at a larger radius (near the centre of the tire) and hence the gearing is effectively more like having the bike in a higher gear than a lower gear.

BTW most weight is on the outside peg when doing donuts, and there is plenty of wheelspin required for that :)
 

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I won't even get into the whole vector force argument! I think you guys know just enough to pose a danger to yourselves...

Riding straight, if you weight the right peg you turn right a little. Now if you do this in a left hand turn, essentially weighting the outside (right) peg, it isn't going to help you turn left. It will pick the bike up a little (decrease lean angle).

For a given body position and speed, the radius of the turn relys on the lean angle of the bike.

If you weight the outside peg, which would decrease the lean angle, you would need to reposition your body further inside the turn to maintain the same turning radius. This would increase the tires' contact patch (due to the contact patch being more centered on the tire from less of a lean) and therefore help reduce wheelspin.

In my opinion simply weighting the outside peg in a turn does jack shit in-and-of itself to prevent wheelspin; but it may make the rider do other things that do help.

Personally, I always thought you weighted the outside peg in a turn to help prevent the rear tire from being lifted if the inside peg touches down. The theory being weighting the peg makes it act rigid, and the bike could pivot on the peg when it is forced into the road. This would/could cause the rear tire to loose some contact with the road and possibly slide out.

From my riding experience, it is helpful with picking the bike up quickly after exiting a corner, and for the above reason as the SuperHawk has low pegs that sometimes touch down.

Feel free to correct me if you think I'm wrong, or add anything I left out...
:cheers
 

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Physics was never my strong point but what Eyespy is saying makes sense.
 

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Stuman said:
So I’ve heard people say that you can help prevent wheel spin by weighting the outside foot peg. There has to be something to this because I’ve heard it from several people, but what I don’t get is how you can put any weight on the outside peg when you’re hanging off the other side of the bike? I mean you would have to actually move your whole body towards the outside of the bike to put more weight on that peg. You could put more pressure on the peg without moving but how would that help stop wheel spin?
Well I do use my outside leg when hanging off to straighten the bike back up, that's defineatelly weighting down the outside peg.
 

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Redlinger said:
I'm sorry but you are mistaken about the requirement for you're mass to be over the pegs for you to use them to support the force produced by gravity. I have no idea how you could even belive this to be true. The force you exert on you're motorcycle due to gravity's pull, the vertical vector if you prefer, can be supported by the pegs. If your legs are sufficently rigid and you have sufficent friction between your peg and your boot then you can transfer the vertical load to the pegs.

If you want a real life example go to a fairly narrow hallway and climb up to the ceiling. Use your legs to press against the walls and walk up the wall. According to you I shouldn't be able to do this, but I can even though my mass isn't over the points of contact at all.

I haven't mentioned th handle bars much because they are irrelevant to this discussion. I only mentioned them because they are possible points of support, though the vast majority of support is through the pegs as I mentioned earlier. Additioinaly Stuman's question was about pegs not handlebars. Out of curiosity how much of you're weight do you support with you're handle bars while cornering?

I'm sorry but your analogy is severely flawed, and you don't even see why, or fail to admit it....
 
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