Body position as a necessity

[Gary856]

The entire statement is false. Hanging off allows you to relax the bike's lean angle but has absolutely no effect on either the vertical or horizontal force vectors.

I'm now confused by this subject. Are you saying hanging off or crossing up has no effect on traction assuming ground clearance is not a concern?

The following article also seems to say there's no consensus on leaning in vs. out?

http://www.motorcycledaily.com/2015/08/shifting-your-weight-to-the-outside-in-a-corner-why/

 

[stangmx13]

hanging off has an effect on traction, but not because its taking a load off the tires. the ground is pushing against the tires. thats the "source" of the force. the ground doesn't care if u are hanging off or not. the force remains the same for a given turn at a given speed. if it didnt remain the same, your line would change.

we hang off because of increase ground clearance, optimizing contact patch, decreased chance of running off the edge of the tire, and because suspension works better at lesser lean angles. the last one likely has the largest direct effect on traction.

that "article" doesn't say anything.

 

[motomania2007]

The entire statement is false. Hanging off allows you to relax the bike's lean angle but has absolutely no effect on either the vertical or horizontal force vectors.

I might not have stated it artfully but here is the logic/theory/practice that I have been taught by numerous folks much more knowledgeable on the subject than me:

Moving your body inside the turn moves the combined center of gravity of the bike and rider more to the inside.

Since the combined center of gravity is more to the inside of the turn, the bike is not leaned as far to go through the turn and is more vertical and thus saves ground clearance.

Because the bike is more vertical, the tires and suspension work better and give more usable traction.

Because you have more usable traction, your bike's tires and suspension can better manage more cornering forces.

In effect, reducing the cornering forces on the bike because you have increased your bikes ability to handle more cornering forces.

I may not be saying it exactly correct but this is the way I have been taught and the way it is explained in any number of books (Roberts, Ienatsch, Code, Lee Parks, etc.) and classes (California Superbike School, Total Control courses...)

 

[stangmx13]

Increase ability to handle cornering forces != reducing cornering forces. U were good until that last paragraph.

 

[tzrider]

Increase ability to handle cornering forces != reducing cornering forces. U were good until that last paragraph.

^^^ This. Leave out the part about reducing cornering force and you’re spot on.

Can’t speak for the other authors you attribute information to but I can assure you Code doesn’t think hanging off reduces cornering force.

 

[motomania2007]

Increase ability to handle cornering forces != reducing cornering forces. U were good until that last paragraph.

^^^ This. Leave out the part about reducing cornering force and you’re spot on.

Can’t speak for the other authors you attribute information to but I can assure you Code doesn’t think hanging off reduces cornering force.

I want to understand this better so please explain.

Obviously the cornering forces themselves did not change in value.

What changed is the amount of cornering forces your bike can handle has been increased by hanging off.

I did not say the cornering forces are reduced, what I said was "In effect, reducing the cornering forces on the bike because you have increased your bikes ability to handle more cornering forces."

Maybe I misunderstand it but, in a simple example: if your bike has the ability to handle 1.0x cornering forces with you not hanging off and it can handle 1.1X cornering forces if you do hang off (thus allowing you to go faster through the same corner), have you not, in effect reduced the cornering forces on the bike since without hanging off the bike it required 100% of your bike's ability to handle the cornering forces and with hanging off the bike only requires about 91% of your bikes ability to handle the cornering forces?

 

[tzrider]

I want to understand this better so please explain.

Obviously the cornering forces themselves did not change in value.

What changed is the amount of cornering forces your bike can handle has been increased by hanging off.

I did not say the cornering forces are reduced, what I said was "In effect, reducing the cornering forces on the bike because you have increased your bikes ability to handle more cornering forces."

I'll clarify as best I can, but am first going to establish what you really did say, which has a lot to do with why I jumped in:

In a simple example, if moving your body to the inside of the curve moved the combind center of gravity of bike and rider 5 degrees to the inside, then the bike could go around the corner with about 5 degrees less lean angle at the same speed. Thus gains ground clearance because the bike is 5 degrees more vertical AND, it increases the forces of gravity downward through the contact patch of the tire and reduces the lateral forces on the tire contact patch saving a little traction.

In the bolded part above, you are saying hanging off:

1. increases the force of gravity downward
2. reduces the lateral forces on the contact patch

Those are unambiguous statements. They may or may not be what you intended to say, but as written, they mean what they mean and they're not correct.

The only ways you can "increase the force of gravity downward" are to make the bike heavier or increase the mass of the planet. As far as I know, hanging off doesn't accomplish that.

The lateral force is a function of velocity and turn radius. Change either of those things and you can affect the lateral force. Hanging off doesn't change lateral force.

But it's true that riders can go faster if they hang off...

Maybe I misunderstand it but, in a simple example: if your bike has the ability to handle 1.0x cornering forces with you not hanging off and it can handle 1.1X cornering forces if you do hang off (thus allowing you to go faster through the same corner), have you not, in effect reduced the cornering forces on the bike since without hanging off the bike it required 100% of your bike's ability to handle the cornering forces and with hanging off the bike only requires about 91% of your bikes ability to handle the cornering forces?

You haven't reduced the cornering forces, you have increased the amount of cornering force the bike can support. Sometimes.

People will say the suspension works better when it's more vertical. This can be true, though sometimes when people hang off they aren't doing it to bring the bike more vertical, they're doing it because they want to go faster and the bike is out of cornering clearance. In that case, the tires and suspension were always able to support a higher lateral load, but if the rider cornered harder, he would drag something hard and pry the tires off the ground. He hangs off as a substitute for leaning the bike more.

Sometimes the road surface is bumpy. This can be a case where relaxing the lean angle (bringing the bike more toward vertical) can increase traction by allowing the suspension to work better. This can increase the amount of available grip.

It's debatable whether relaxing the lean angle presents a better contact patch to the ground. There was a time where this was generally true, but if we are using a modern race tire, the part of the tire you're on when the bike is leaned to the paint is as good as it gets. They make them that way in order to support the highest lateral loads possible.

One last benefit of hanging off that comes to mind is this: Sometimes traction is quite poor and hanging off won't really improve it. Think of a wet, gravelly road where you can't lean the bike over very far. Hanging off can get the bike closer to vertical and in this case, if the bike has a big slide, you have a little more time to recover the slide before the bike hits the ground.

 

[stangmx13]

IMO "in effect" is comparable to "it feels like". thats fine. "it feels like ive reduced cornering forces" isnt wrong. but u havent reduced cornering forces, so why bother saying it...

too often in motorcycling, we trick ourselves into believing something that isnt there. if u hang off like Marquez, u likely reduce your bike's lean angle by at most 10 degrees. any gain in "ability to handle cornering forces" from suspension improvements due to less lean angle is small, likely very very small. u don't have 50% more grip at 0deg lean angle compared to 45deg. so theres no way u are getting a lot from a 10deg change. id guess theres much less than a 5% change in measurable friction. yet riders seem to feel twice as much grip when hanging off :laughing

 

[Smash Allen]

looking at my track notes i see that almost every day includes "holy shit omg so much easier when i don't move so much" :laughing

then i get tired and start moving around on the bike like a monkey :wtf i would think that i would move less as i get tired...

 

[stangmx13]

the main reason why I hang off is because its "free turning". as a racer, its my goal to minimize any time spent using max grip or max cornering forces. an easier analogy, though not completely synonymous, is that I want to minimize my effective lean angle in all turns. so how does hanging off accomplish this...

a motorcycle around a track spend a lot of time NOT at max lean angle. theres large portions of each corner where im adding lean angle to tip in and subtracting lean angle to exit. we know that im not using max cornering forces here since my turning radius isnt that sharp. so I can safely use more cornering force by hanging off without adding any risk. this decreases my turning radius and gives me some "free turning". because I accomplish more turning here, I don't need to turn as much when im actually using max cornering forces (at or near max lean angle). so either I decrease the max or use my max for less time, depending on the corner. both are beneficial to the lap time since I can brake later/hard or accelerate sooner/hard.

this difference isnt that hard to see at a trackday. a slower rider may tip into the corner, get their knee on the ground, and hold that lean angle all the way to the exit curb. a much faster rider will NEVER have that much lean angle near the exit curb because they accomplished more turning much sooner in the corner.

 

[stangmx13]

looking at my track notes i see that almost every day includes "holy shit omg so much easier when i don't move so much" :laughing

then i get tired and start moving around on the bike like a monkey :wtf i would think that i would move less as i get tired...

how u move is really important, both for saving energy and maximizing performance. the closer I get to the limit of my equipment, the more I notice this. when I get tired, I tend to use my arms more to move. it somewhat feels like im hanging off more. it makes riding the bike harder. and its risky as it can ask for more front grip. its just bad all around. if u find that riding is harder when u move around, I wouldn't be surprised if u are doing something wrong. maybe u are making the same mistakes I am.

lately, ive really been focusing on using my legs and core to initiate any movement, esp in fast transitions. its not a simple change and my legs were wrecked the first weekend where I really focused on it. but it think its going to be great for my riding eventually.

 

[Smash Allen]

how u move is really important, both for saving energy and maximizing performance. the closer I get to the limit of my equipment, the more I notice this. when I get tired, I tend to use my arms more to move. it somewhat feels like im hanging off more. it makes riding the bike harder. and its risky as it can ask for more front grip. its just bad all around. if u find that riding is harder when u move around, I wouldn't be surprised if u are doing something wrong. maybe u are making the same mistakes I am.

lately, ive really been focusing on using my legs and core to initiate any movement, esp in fast transitions. its not a simple change and my legs were wrecked the first weekend where I really focused on it. but it think its going to be great for my riding eventually.

same here, my thighs get tired (i have a habit of lifting my butt too high when i transition which doesn't help) and it becomes easier to pull myself over on exit / push myself over on entry...both things which upset the chassis and slow me down...not to mention as you said it asks the front for more grip at the wrong time.

by leaving my lower body more centered (half a cheek or less off the seat) it saves energy and keeps chassis stable

it sounds like moving with the lower body before the upper body is like going to the rear brake before the front in the sense that it is easier on the chassis and keeps things settled

there is a quick transition at buttonwillow turn 3 with a right-left-right - Cory Call uses the throttle to pick up the bike between the first right and the left - have you tried using the throttle to help pick the bike up during quick transitions?

i'm starting yoga classes this week :teeth no more excuses, i am going to really strengthen my core

back on topic of body position RE: street riding, i would say that it is necessary because the difference between a slow street ride and a blistering race pace is just the degree of application. so, you would still use body positioning, just at a lesser degree of application

 

[motomania2007]

I'll clarify as best I can, but am first going to establish what you really did say, which has a lot to do with why I jumped in:

...

You haven't reduced the cornering forces, you have increased the amount of cornering force the bike can support. Sometimes.

People will say the suspension works better when it's more vertical. This can be true, though sometimes when people hang off they aren't doing it to bring the bike more vertical, they're doing it because they want to go faster and the bike is out of cornering clearance. In that case, the tires and suspension were always able to support a higher lateral load, but if the rider cornered harder, he would drag something hard and pry the tires off the ground. He hangs off as a substitute for leaning the bike more.

Sometimes the road surface is bumpy. This can be a case where relaxing the lean angle (bringing the bike more toward vertical) can increase traction by allowing the suspension to work better. This can increase the amount of available grip.

It's debatable whether relaxing the lean angle presents a better contact patch to the ground. There was a time where this was generally true, but if we are using a modern race tire, the part of the tire you're on when the bike is leaned to the paint is as good as it gets. They make them that way in order to support the highest lateral loads possible.

Thanks for working through it with me.

I know that modern tires flex/deform to provide a mostly consistent traction between the tire and the pavement as the tire is leaned. Older technology tires tend to not do this particular aspect well at all and thus leaning more = both less traction being available and more of the available traction being consumed by the lateral cornering forces.

One last benefit of hanging off that comes to mind is this: Sometimes traction is quite poor and hanging off won't really improve it. Think of a wet, gravelly road where you can't lean the bike over very far. Hanging off can get the bike closer to vertical and in this case, if the bike has a big slide, you have a little more time to recover the slide before the bike hits the ground.

About 1986 or maybe 1987, I spoke with a professional racer after a raining FZ600 cup race at Riverside Raceway and he said something very similar. Something about having more time to decide whether you are able to gather it back up from a slide before you have to let go and bail off. I am not remembering it exactly correct as we were all rolling with laughter the way he said it. BTW, most of the leaders of the race fell at least once during that race... it poured that day! Thanks for bringing that memory back!

 

[stangmx13]

same here, my thighs get tired (i have a habit of lifting my butt too high when i transition which doesn't help) and it becomes easier to pull myself over on exit / push myself over on entry...both things which upset the chassis and slow me down...not to mention as you said it asks the front for more grip at the wrong time.

by leaving my lower body more centered (half a cheek or less off the seat) it saves energy and keeps chassis stable

it sounds like moving with the lower body before the upper body is like going to the rear brake before the front in the sense that it is easier on the chassis and keeps things settled

there is a quick transition at buttonwillow turn 3 with a right-left-right - Cory Call uses the throttle to pick up the bike between the first right and the left - have you tried using the throttle to help pick the bike up during quick transitions?

i'm starting yoga classes this week :teeth no more excuses, i am going to really strengthen my core

back on topic of body position RE: street riding, i would say that it is necessary because the difference between a slow street ride and a blistering race pace is just the degree of application. so, you would still use body positioning, just at a lesser degree of application

oh man, half a cheek or less is def not hanging off very much. I don't think id ever suggest someone on the track hang off that little. cmon, its only 6 laps

IMO the importance of moving w/ your legs is less about timing, upper vs lower body first, and more about what u are pushing on. pushing on the pegs to move is far better than pushing/pulling on the bars. once u remove a little lean angle during the transition, its possible to push off the inside peg to get to the other side of the bike. then once over there, u load the outside peg as the bike falls in and it becomes the inside peg. I think this helps for a faster transition than pulling on the bars or even pulling with your inner thigh. plus, the quads are much stronger than hip adductors.

if I get into T3 correct, I def use the throttle some before T4. but I can't say that ive heard felt the throttle actually causes a bike to reduce its lean angle. ive never found anything in the math/physics that suggests it either. so I think its just a side-effect of things the rider does while getting on the gas. we can find plenty of pics on the internet w/ GP bikes lofting a wheelie w/ 20deg of lean angle. if this magical force existed, ud think that wouldn't be possible.

squats and deadlifts!

 

[Smash Allen]

oh man, half a cheek or less is def not hanging off very much. I don't think id ever suggest someone on the track hang off that little. cmon, its only 6 laps

bro have you seen my ass? it's huge :laughing

i've recently discovered that what i think i do on the bike is oftentimes much different than what i actually do on the bike. that said, i may think i hang half a cheek now but maybe it's more...i'm not certain of anything at this point. i just got a datalogger and so from now on my sessions will have 1khz gps timer + 32 channels of data so i can prove how bad i am to myself, in the never ending effort to go faster

IMO the importance of moving w/ your legs is less about timing, upper vs lower body first, and more about what u are pushing on. pushing on the pegs to move is far better than pushing/pulling on the bars. once u remove a little lean angle during the transition, its possible to push off the inside peg to get to the other side of the bike. then once over there, u load the outside peg as the bike falls in and it becomes the inside peg. I think this helps for a faster transition than pulling on the bars or even pulling with your inner thigh. plus, the quads are much stronger than hip adductors.

if I get into T3 correct, I def use the throttle some before T4. but I can't say that ive heard felt the throttle actually causes a bike to reduce its lean angle. ive never found anything in the math/physics that suggests it either. so I think its just a side-effect of things the rider does while getting on the gas. we can find plenty of pics on the internet w/ GP bikes lofting a wheelie w/ 20deg of lean angle. if this magical force existed, ud think that wouldn't be possible.

squats and deadlifts!

yea i agree with that. if i lower the pegs an inch or so it is much easier to last full race distance but i just don't want to have to lower my pegs more because i give up ground clearance and scrape...shit wait i just realized i haven't tried lowering them since changing ride height and geometry...guess i know what i'm working on this month, thanks :thumbup:ride

will yoga and wall sits suffice? i also walk a couple miles a day...fuck i really don't want to have to start squat and deadlifts

 

[stangmx13]

bro have you seen my ass? it's huge :laughing

i've recently discovered that what i think i do on the bike is oftentimes much different than what i actually do on the bike. that said, i may think i hang half a cheek now but maybe it's more...i'm not certain of anything at this point. i just got a datalogger and so from now on my sessions will have 1khz gps timer + 32 channels of data so i can prove how bad i am to myself, in the never ending effort to go faster

yea i agree with that. if i lower the pegs an inch or so it is much easier to last full race distance but i just don't want to have to lower my pegs more because i give up ground clearance and scrape...shit wait i just realized i haven't tried lowering them since changing ride height and geometry...guess i know what i'm working on this month, thanks :thumbup:ride

will yoga and wall sits suffice? i also walk a couple miles a day...fuck i really don't want to have to start squat and deadlifts

:laughing

ya I def struggle w/ "did I actually do what I think I did". also "did I really feel that or did my mind make it up"

shorter pegs provide more ground clearance too if u don't have huge feet. oh, and so does hanging off :laughing

I have no idea if yoga and wall sits are enough for u. "enough" depends on your goals for racing too. im very light (5'9'@140) so its ez for me to get away w/ general fitness for club races. but im def lacking for MA races that are 3x as long. I cycled 100mi last weekend, will be doing some squats and deadlifts this week, and will prob go climbing 2x this week.

 

[Smash Allen]

:laughing

ya I def struggle w/ "did I actually do what I think I did". also "did I really feel that or did my mind make it up"

shorter pegs provide more ground clearance too if u don't have huge feet. oh, and so does hanging off :laughing

I have no idea if yoga and wall sits are enough for u. "enough" depends on your goals for racing too. im very light (5'9'@140) so its ez for me to get away w/ general fitness for club races. but im def lacking for MA races that are 3x as long. I cycled 100mi last weekend, will be doing some squats and deadlifts this week, and will prob go climbing 2x this week.

I’m slowly converting my pegs to shorties, at least on the right side...there’s a hint there somewhere for someone smarter than I :laughing

I’m 6’5” 200lbs. Walk dogs 2 miles a day, work shoulders and arms everyday, bench a few times a week. If I took bicycle to work that would be 35 miles a week, wtf you do 100 miles in a weekend?? Come on, we sit down on motorcycles no need to work out legs...

 

[stangmx13]

I got a friend to watch 5min of road racing on TV a while back. they knew I went to the track and knew I thought it was physically a lot of work. but still they asked, "they just sit there, whats so hard about it?" :facepalm :laughing

 

[ZCrow]

Such a long thread for a simple question. The short answer is there is little benefit to over committing on the street. You simply cannot go fast enough on the street and stay out of jail to justify it.

Not that will stop anyone, because we all want to look cool right. :teeth

But definitely do some track days. It will open your eyes to how slow you and your ridding buddies have been all this time.

 

[Spencerjo]

Indeed - Nice thread This has been very educational.

Thanks all for the responses and discussion. I've started playing around more with the difference between pure countersteering and using body position. Doing so with the info here at top of mind has advanced my understanding. As said here, it seems rare that I'll want to use purely one technique, rather, at all times, I'll be using a blend of the two, and the ratio of that mixture will depend on the situation. To some extent, I was doing this naturally already when I anticipated a low-traction surface - I would stand the bike up while levering my body out to keep the same turning force while having bike more upright.

What this thread really helped me with was to gain more confidence in leaning the bike *without* moving my body too much - I think I was afraid of this before and it made me overthink things. Now, practicing, I think I'm getting a much better feel for both.

All that said, what I think I really need at this point is more group rides where I can observe other riders and have them observe me. That... and track days