Weighting the outside peg….

[LowHangingFruit]

Hey Barfers,

Been trying to wrap my head around Pivot Steering and folks who say that weighting the outside peg helps “pivot the bike”. I’m BY NO MEANS an expert rider; intermediate at best with some track and dirt experience. However, I really struggle to understand how, during spirited street or track riding, how weighting the outside peg in corners helps. Of course I weight the outside peg on flat corners in dirt, but in high grip situations on a street bike? Just does not compute for me! I’ve had VERY experienced racers/street riders try to explain the physics but I’m at a loss.

Thanks y’all!

 

[wheel_muse]

I don’t get that either. As a long time both bicycle and moto rider, I sometimes feel confused. Getting weight down lower makes both machines more stable in turns.

On a bicycle, in steep lean angles, you can’t weight the inside pedal because it will drag or even lift wheels off the pavement. But on a moto, weighting the inside peg feels so much more stable and controlled.

 

[Cupid's Arrow]

The latest Doc Wong clinic pertained to pivot steering and I believe he said that in addition to being able to apply more force more quickly to the handlebar, thus turning much quicker and requiring less lean angle, it also stabilizes the bike in the turn like @wheel_muse mentioned. I also don't know the first thing about the physics behind it. Perhaps some videos explaining it online? I knew about counter steering and knew that it worked but never understood the mechanics of it until I watched this video.

 

[zanshin]

Great questions, these. This stuff begins to truly matter when you're running out of traction and/or clearance, which is a significant threshold to exceed on pavement with good tires under good conditions (on a bike with typical clearance). Under chill street or track day conditions, you can sit any which way and do whatever goofy thing and you'll be perfectly fine.

The laboratory of choice for exploring these dynamics is the dirt, where you run out of traction easily indeed. You can weight the inside peg, outside peg, slide back on the seat, choke up on the tank, flat track the inside foot, outside knee in the tank, outside knee loose, elbows up, wrist turned this way or that, try all the combinations and sequences and observe the effects -- what happens to traction at the front, rear, overall; how well does it hook up on acceleration; how effective is braking; can you track the back end out while the front is stable; can you drift controllably.

As my authority of choice, I will rely on Chris Birch with whom I've had the pleasure of riding twice now.. and he says, "when in doubt, weight the outside peg." Inside peg for turn initiation, optionally.

The outside pegs are getting a lot of use:

but the more interesting question is:
1) bike maximally vertical and body leaning in
2) bike and body in line
3) bike down while the body is upright?

The answer is clearly 'yes' -- all of these are part of the toolkit. But pavement riders start with 2, transition to 1, begin to disparage 2 "because look at Marquez", and are deeply ignorant of the magic that is 3.

Personally, riding a lot of tall enduro/ADV machines with tons of clearance, I use 3 most of the time. Weight on the outside peg, knee in the tank pushing the bike down, body upright, grab fistfuls of throttle and enjoy. It's the dirt way, and it's great for sliding, drifting, or dealing with variable traction. Can weight the inside during turn initiation, optionally.

 

[zanshin]

And as part and parcel of #3 above, outside elbow up and out, inside elbow more straight, and grip/wrists rotated out to come at the bars more from the side than dead on. Gentle grip, like you're holding eggs. Minimize tension on the forearms, upper arms. Grip the bike strongly with the legs. Outside ankle is driven into the side of bike, locked in using the friction of the peg teeth against the sole.

 

[stangmx13]

The physics of peg weighting can be simplified. You have nothing outside the you-moto system to push against, so weighting a peg does almost nothing. A good analogy for peg weighting may be like pumping your legs on a swing. That first leg pump creates a very small change. And you accomplish nothing more if you hold your legs out. Same with peg weighting.

If you are riding down the freeway and do a sudden and forceful single less press into a peg - you go up, the peg goes down, and the moto leans a little that way. Then the momentary force stops and the moto leans back upright. In the end, very little happened. The reason anything happened is mostly because of friction. The restoring forces to bring the moto back upright were a tiny bit smaller than the original leg press, so the moto's direction changed a tiny tiny bit. Because of this, peg weighting is useless as the sole way of causing a direction change on a moto.

However, what if we do peg weighting in conjunction with other inputs? If we do the peg weighting at the same time that we make a steering input, maybe the steering input can be a little smaller. Both the steering input and peg weight were short sudden inputs, so they can add together. This applies to all other situations too. When the rear tire slides, we probably want to do some body-position change or steering input to reduce the consequences of that slide. Maybe we also do a peg weighting so that steering input can be smaller or unnecessary. Or maybe a weighting helps the body-position change to reduce the slide. Peg weighting is just another input... but it's a momentary input, not a constant input.

The internet tries to oversimplify complicated concepts way too much. "Weight the outside peg" is one of those cases. Doing so will provide almost no benefit any time the moto is in some constant state. Every moment that your turning radius is constant, weighting a peg is doing nothing. And weighting the outside peg on corner entry may be counter-productive. So you'd be wasting A LOT of energy holding that outside thigh all tensed up. You can ride better than "always ready for a slide because I always weight the outside peg".

 

[tzrider]

The latest Doc Wong clinic pertained to pivot steering and I believe he said that in addition to being able to apply more force more quickly to the handlebar, thus turning much quicker and requiring less lean angle, it also stabilizes the bike in the turn like @wheel_muse mentioned. I also don't know the first thing about the physics behind it. Perhaps some videos explaining it online? I knew about counter steering and knew that it worked but never understood the mechanics of it until I watched this video.

This is the closest answer to explaining what Keith Code was describing with "Pivot Steering." I've never loved the term, but I don't have a better one.

When you apply pressure to the outside peg, this provides a brace to oppose the force you put into the bar when countersteering. One way to understand what this does is to stand facing a wall, feet about shoulder width apart and two or three feet from the wall. Place your right hand against the wall and lift your left foot off the floor. Try to push against the wall. Then switch feet; place your left foot on the floor and lift the right foot. Press the wall with your right hand. You should be able to press harder without disturbing your body.

This diagonal opposing force just places your body mass between your right hand and left foot, minimizing the tendency for your body to move when you press hard. It works on the bike this way too, even though you have other points of contact on the bike, like your butt on the seat. The effect is most noticeable at higher speeds, where it takes more bar force to turn the bike quickly.

 

[budman]

I did it a lot racing MX and as Zanshin noted it involves knees, elbows and body weight.

I too sometimes ride my Multi like a big dirt bike and do the same things, but really the minimal weight is not doing a lot other than solidifying the control of the bars... plus it feels bad ass.

 

[ST Guy]

I remember a ride I went on in the high Sierras. My wife was a passenger. We were on my ST1100. The pace was brisk, to say the least. As I entered one left hander a bit too fast, I felt hard bits grinding on the pavement. And I still had a tightening radius to go through. Otherwise I’d go off the road and down a cliff. What I did was to instantly and intuitively slide my butt to the inside of the turn, effectively hanging off. That bought me more ground clearance and my wife never knew how close we’d come to crashing.

 

[two wheel tramp]

This is the closest answer to explaining what Keith Code was describing with "Pivot Steering." I've never loved the term, but I don't have a better one.

When you apply pressure to the outside peg, this provides a brace to oppose the force you put into the bar when countersteering. One way to understand what this does is to stand facing a wall, feet about shoulder width apart and two or three feet from the wall. Place your right hand against the wall and lift your left foot off the floor. Try to push against the wall. Then switch feet; place your left foot on the floor and lift the right foot. Press the wall with your right hand. You should be able to press harder without disturbing your body.

This diagonal opposing force just places your body mass between your right hand and left foot, minimizing the tendency for your body to move when you press hard. It works on the bike this way too, even though you have other points of contact on the bike, like your butt on the seat. The effect is most noticeable at higher speeds, where it takes more bar force to turn the bike quickly.

so weird that i was just messaging you about this very thing yesterday and here it is on barf. thanks for this explanation.

 

[NVDucati]

The non-helpful answer is ...it is the same as snow skiing. The more specific answer is that putting weight on the outside peg relocates the center of mass. Notice I don't say the center of gravity. The difference between CoM and CoG is best left for a different forum .
The simple way to look at is to start with straight line riding where if you switch from sitting on the seat to standing on the pegs ~ the load moves lower. And that is true even if you bend your knees so that you butt is almost touching the seat. The load has shifted to the foot pegs.
_ So when you "weight" the outside peg you are relocating the load to be closer to a spot between the contact patches of the tires.

 

[stangmx13]

The non-helpful answer is ...it is the same as snow skiing. The more specific answer is that putting weight on the outside peg relocates the center of mass. Notice I don't say the center of gravity. The difference between CoM and CoG is best left for a different forum .
The simple way to look at is to start with straight line riding where if you switch from sitting on the seat to standing on the pegs ~ the load moves lower. And that is true even if you bend your knees so that you butt is almost touching the seat. The load has shifted to the foot pegs.
_ So when you "weight" the outside peg you are relocating the load to be closer to a spot between the contact patches of the tires.

Nope. Forces don’t work that way.

If you tense a leg to weight a peg, but don’t actually move, you have not moved any mass. The CoM has not changed. If you lift your butt off the seat 1mm, the CoM didn’t move lower because of the pegs. It raised some amount on the order of 1mm because you raised some mass.

CoM and CoG are the same in a uniform gravity field.

 

[NVDucati]

Nope. Forces don’t work that way.

If you tense a leg to weight a peg, but don’t actually move, you have not moved any mass. The CoM has not changed. If you lift your butt off the seat 1mm, the CoM didn’t move lower because of the pegs. It raised some amount on the order of 1mm because you raised some mass.

CoM and CoG are the same in a uniform gravity field.

Like I said: The difference between CoM and CoG is best left for a different forum .

 

[stangmx13]

Like I said: The difference between CoM and CoG is best left for a different forum .

You are making up a difference btw CoM & CoG, refusing to explain that difference, then making a bunch of claims based on that difference. Are you trolling?

The claims in your prev post are incorrect. They arent helpful in this thread.

 

[NVDucati]

You are making up a difference btw CoM & CoG, refusing to explain that difference, then making a bunch of claims based on that difference. Are you trolling?

The claims in your prev post are incorrect. They arent helpful in this thread.

No, not trolling. But I just went back and re-read your post #6. You take a pretty hard position that weighting a foot peg makes no difference. In no way did I mean to defy your authority. I apologize.

 

[Das MotorRad]

if the rear tire is at risk of sliding out, are you better off 100% weight on seat? 100% weight on pegs? 50/50? 50% seat, 10% inside foot, 40% outside foot? hopefully not 30% handlebars, 60% seat, and 10% pegs...

 

[SFMCjohn]

I wonder if “putting weight on the outside peg”/“apply pressure to the outside peg” is why we see the MotoGP guys take their inside foot completely off the peg and dangle their leg? are they setting up Mr Code’s pivot steering?

why they do that has been explained to me several times, but I can never remember the answer.

 

[stangmx13]

No, not trolling. But I just went back and re-read your post #6. You take a pretty hard position that weighting a foot peg makes no difference. In no way did I mean to defy your authority. I apologize.

"no difference"? You're joking right? That post literally describes the small differences and how that can be turned into an advantage. Please read more carefully or stop trolling.

 

[stangmx13]

if the rear tire is at risk of sliding out, are you better off 100% weight on seat? 100% weight on pegs? 50/50? 50% seat, 10% inside foot, 40% outside foot? hopefully not 30% handlebars, 60% seat, and 10% pegs...

Good questions.

I doubt anyone can do 100% anything. Even with just sitting on the seat, you'll still be leaning on the tank and the bars some amount. Even if you stand on one peg, you are still leaning forward some and likely have some weight on the bars.

Define "risk of sliding out"? Is this risk "I'm at the track, I've been through this corner 40x today"? Or is it "Im in the mountains, it's cold, and ive never ridden this road before"? I think this matters a lot. On the track, I'll try to min/max everything. I'll be pushing on the inside peg for adding lean angle (sometimes), relaxing onto the seat for constant lean angles, and pushing on the outside peg for removing lean angle. Since risk of rear slide is higher on exit with the addition of throttle, that condition ends up being more weight outside peg. For the street situations, I tend not to do any of that and just kinda ride neutral.

Also, 30% bars, 60% seat (including tank), 10% pegs is probably pretty common during hard braking. The pegs are behind or almost behind your CG. They can't contribute much reaction force during braking.

 

[Cupid's Arrow]