Which leg to push with??

[Matt Gephart]

I did a search and couldn't find anything on this. It may seem like a dumb question, but it's something that I just noticed and am wondering if anybody actually knows the correct answer.

Which peg are you supposed to put the most pressure on when cornering (inside or outside)?

I put most of my weight on my inside leg; so much that I can basically take my outside leg off of the peg while cornering. This weekend I asked a priveteer racer in superbike why Rossi and the like would take their leg off while breaking for a corner; he said outside leg, but I don't know if he was just drunk or what. After watching the races I noticed that some of the GP racers will have their foot off the peg all the way into the corner, and sometimes even move their inside foot around mid corner. This would tell me that most of their peg pressure is through the outside leg.

Have I been doing this wrong the whole time? I can corner just fine, but if I'm doing it wrong I'm sure I have great room for improvment.

Thanks - matt

 

[Blinky]

I have read that they stick their leg out to get more wind resistance to slow down when they come in hot. If you watch, they do not do that all of the time.

I put wait on the inside peg. If u were putting weight on the outside, wouldn't it feel like you will be standing the bike up or switching cornering sides. I grip the tank with my outer leg too.

 

[vinny337]

My weight is on the inside peg, my outside leg grips the tank...I also try to keep the bike up as much as possible by exaggerating keeping my head down and looking into the turn. That's what works for me…opcorn:

 

[HondaGalToo]

I weight the inside for turn in, then the outside peg on corner exit as I'm standing the bike up.

 

[Meat]

Ok, from the standpoint of physics if you lean to the inside you better react that load with the inside peg. If you try to react that load with the outside peg, you will end up jumping off the bike to the inside.

Maybe when people talk about weighting the outside peg in a turn, they are talking about something all together different. But based on physics the answer is very easy. You can keep from falling off the bike to the inside by pushing your inside foot on the inside peg and you can also use your outside thigh against the outside of the tank (or something similar, such as calf on side of bike).

There is a way that you could use friction of your outside boot against the outside peg and couple that against the tank (to react the moment caused by the cantilevered beam you just made out of the rider), but you are talking about a lot of load to react that way.

And I don't see the bike knowing the difference since the CG doesn't change no matter where on the bike you react the load of the rider (provided the rider is in the same position). And the combined CG of bike and rider does not change based on the points at which you try to react the load.

 

[vinny337]

Meat;132326 wrote: Ok, from the standpoint of physics if you lean to the inside you better react that load with the inside peg. If you try to react that load with the outside peg, you will end up jumping off the bike to the inside.

Maybe when people talk about weighting the outside peg in a turn, they are talking about something all together different. But based on physics the answer is very easy. You can keep from falling off the bike to the inside by pushing your inside foot on the inside peg and you can also use your outside thigh against the outside of the tank (or something similar, such as calf on side of bike).

There is a way that you could use friction of your outside boot against the outside peg and couple that against the tank (to react the moment caused by the cantilevered beam you just made out of the rider), but you are talking about a lot of load to react that way.

And I don't see the bike knowing the difference since the CG doesn't change no matter where on the bike you react the load of the rider (provided the rider is in the same position). And the combined CG of bike and rider does not change based on the points at which you try to react the load.

Meat you wouldn't happen to be an engineer, would you?

 

[Meat]

vinny337;132330 wrote: Meat you wouldn't happen to be an engineer, would you?

lol....Aeronautical. I am a contract stress analyst.

I do try to keep things simple so non-engineering people will understand , but add in small things so that another engineering type doesn't jump in with, "but this', and "but that".

It would definitely easier just to use engineering terms and jargon.

 

[HondaGalToo]

oooooo, I love it when you talk physics!

Kevin Schwantz said to weight the outside peg on corner exit just a bit to help with traction. So, that's why I do it. I don't know if it makes sense from a physics standpoint!

 

[Gorecki]

I'm probably the least experienced here but as I understand it, the outside peg can be used as a support for counter steering on the otherside. Not to 'weight' the peg but as a pressure point aka 'pivot point' to provide additional sense of stability in the turn.

 

[Matt Gephart]

Great. I figured I do it correctly, but if there was a way to get quicker....

You are correct when you say that when everything is static, that it won't change the COG and assuming both positions are the same, would have no affect on cornering perfomance. If it were possible to push with different legs, I thought it might move my position on the bike in a way which would increase cornering ability.

If it were, you guys would have answered "hell yeah, you are supposed to weight your outside leg, how have you not crashed yet?", then I would give it a shot. Otherwise I'll just keep plugging along trying to get faster in other ways.

BTW, I'm also an Enginner designing spinal and orthopedic implants and instruments so some jargon would be just fine!

-Matt

 

[sobottka]

HondaGalToo;132337 wrote: oooooo, I love it when you talk physics!

Kevin Schwantz said to weight the outside peg on corner exit just a bit to help with traction. So, that's why I do it. I don't know if it makes sense from a physics standpoint!

bingo! outside peg!

 

[Meat]

sobottka;132371 wrote: bingo! outside peg!

How? Your CG is to the inside of the bike's CG. Even when you take into account that the resultant force of the bike+rider is going down through the centerline of the bike to the pavement, the rider's CG is still to the inside.

That is like standing upright and leaning to your left. You can't put any more force on your right foot without moving your body (changing your CG). You can't put more force on your left foot without changing your CG either.



And yes we statically represent what some would call dynamic (in engineering the term dynamic refers to vibrations in most disciplines), but we will call moving. That is how we analyze all structure on aircraft, and fighters move much faster than motorcycles with more things moving and affecting loading (such as wing bomb dropping during maneuvers, etc). Statics always applies at any moment in time for a moving object. The laws of physics will apply just the same.

 

[ninjamansc]

I wouldn't get all wrapped around the axle about peg weighting. I weight both pegs equally (maybe the inside a little more) because it's easier on the legs and I'm lazy.

General body position is more important. Head/shoulders/upper body low and to the inside. It'll allow less lean angle for a given speed, so you can brake a little deeper and get on the gas harder.

 

[Meat]

You can't weight the pegs equally if your CG is to the inside of the motorcycle. Put scales under a chair, lean to the side....the scales show the chair is reacting more load on the side you are leaning toward.

And I am simplifying things because it is understood that the resultant force is through the shear center of the bike+rider.

I am just dying to see someone take their knees off the tank, take their inside foot off the inside peg, lean to the inside of the bike and try oh so hard to not fall off the bike by weighting the outside peg.....of course we will be keeping our hands loose and not supporting our weight by those either.

Until someone rewrites physics, this is very simple.

Or unless someone is meaning something totally different than reacting the load of the rider when they say "weighting the pegs".


(I know Steve-o said he weighted the inside peg more)

 

[sobottka]

Meat;132424 wrote: You can't weight the pegs equally if your CG is to the inside of the motorcycle. Put scales under a chair, lean to the side....the scales show the chair is reacting more load on the side you are leaning toward.

And I am simplifying things because it is understood that the resultant force is through the shear center of the bike+rider.

I am just dying to see someone take their knees off the tank, take their inside foot off the inside peg, lean to the inside of the bike and try oh so hard to not fall off the bike by weighting the outside peg.....of course we will be keeping our hands loose and not supporting our weight by those either.

Until someone rewrites physics, this is very simple.

Or unless someone is meaning something totally different than reacting the load of the rider when they say "weighting the pegs".


(I know Steve-o said he weighted the inside peg more)

your too smart for your own good... in your chair example your forgetting about the fact that the chair isnt turning, generating inertia or you could weight the outside leg/peg and that a motorcycle has a forward and a rear contact patch ...not front left/right- rear left/right like a chair.
you can say it aint so but i weight the outside peg

 

[dbakerpa]

Rossi says he weights the inside coming in and shift the weight outside as he leaves the apex.

 

[Meat]

sobottka;132450 wrote: your too smart for your own good... in your chair example your forgetting about the fact that the chair isnt turning, generating inertia or you could weight the outside leg/peg and that a motorcycle has a forward and a rear contact patch ...not front left/right- rear left/right like a chair.
you can say it aint so but i weight the outside peg

It is important for you to actually read my post before you tell me that I am wrong. I stated that I was simplifying things because it is understood that the resultant force is through the shear center of the bike+rider. What this means in general (it is very simplified version....and I am actually just summing forces to come up with a close approximation) is that the bike is leaned at an angle such that the resultant force, which includes the effects of centripetal force (mass * velocity^2/turning radius) as well as gravitational force. These balance themselves to result in the lean angle of the bike. So, I stated all that in a simple sentence that you just blew right over. If you don't understand something just ask. I honestly try to make these things easy to understand by common people, but I do slip (like shear center) from time to time.

So, if you just take the bike leaned over on the track and rotate your reference axis (meaning apply all the same forces but rotate it so the resultant force is straight downward) toward the ground. Then you will see that the chair example is correct.

A front and rear contact patch has absolutely no relevance in this case. Only concerned with side to side.

Inertia has nothing to do with this. We are talking about turning. If you are talking about centripetal force/acceleration I already addressed that.

I am only using a simple static freebody to simplify things, which is how we design aircraft by hand everyday

 

[sobottka]

Meat;132466 wrote: It is important for you to actually read my post before you tell me that I am wrong. I stated that I was simplifying things because it is understood that the resultant force is through the shear center of the bike+rider. What this means in general (it is very simplified version....and I am actually just summing forces to come up with a close approximation) is that the bike is leaned at an angle such that the resultant force, which includes the effects of centripetal force (mass * velocity^2/turning radius) as well as gravitational force. These balance themselves to result in the lean angle of the bike. So, I stated all that in a simple sentence that you just blew right over. If you don't understand something just ask. I honestly try to make these things easy to understand by common people, but I do slip (like shear center) from time to time.

So, if you just take the bike leaned over on the track and rotate your reference axis (meaning apply all the same forces but rotate it so the resultant force is straight downward) toward the ground. Then you will see that the chair example is correct.

A front and rear contact patch has absolutely no relevance in this case. Only concerned with side to side.

Inertia has nothing to do with this. We are talking about turning. If you are talking about centripetal force/acceleration I already addressed that.

I am only using a simple static freebody to simplify things, which is how we design aircraft by hand everyday

i'm a mere common man and dont understand any of this thats why i say you are too smart for your own good!
dont bother trying to explain ...keep weighting the inside peg

 

[moto_mx131]

Makes the bike feel better to me when i weight the outside peg when powering out if a turn.

 

[sobottka]

another good example might be the "rossi" technique of dangling the inside leg on corner entry. i would say that insude peg is totally unweighted at that point, no? :dunno: