People are daft, how on earth would anyone with a basic understanding of physics could think standing up lowers your COG?

@TriAngles3D

2 ай бұрын

Those that comprehend why some people think like that are smart.

@PeterBaumgart1a

2 ай бұрын

They confuse it with lowering the rider's Pivot Point (that is moving lower, to the pegs, when you stand up) with the CoG.

@dsackman1495

2 ай бұрын

I think the operative word is "basic understanding". Maybe understanding of basic physics is not for some / many. But then, there are people who believe the earth is flat and that the earth quake in New York was a "sign from God". 😃😃😃

@rivernet62

2 ай бұрын

You said what I tried to say but simpler. Nice job.

@MrBulli69

2 ай бұрын

@@TriAngles3D those that use the word smart instead of intelligent often aren't 😉 sorry couldn't resist as you seem to be having a subtle dig.

The comments demonstrate that the term "center of gravity" is as universally misunderstood and misapplied as the term "contact patch". The crisis is not in understanding, it is in finding correct words for what we want to describe. The fundamental of standing up while riding is that the rider is decoupled from the bike, and trying to talk about that in terms of CoG is inappropriate.

@MrBulli69

2 ай бұрын

And yet you can calculate where the centre of gravity is. I understood exactly to what he was referring. CoG is a term that is perfectly applicable in this way.

@rivernet62

2 ай бұрын

@@MrBulli69 I believe you refer to the center of mass, which is usually applied to a rigid system (unless you are speaking of planets or galaxies). A standing rider is no longer rigid wrt his/her bike.

@MrBulli69

2 ай бұрын

@rivernet62 a standing rider constantly moves the COG when moving their body. As you can see above CG is a term used

@garnet4846

2 ай бұрын

Center of "gravity" is a nonsense term, replace it with center of mass.

@dkindig

2 ай бұрын

@@MrBulli69 True, even a sitting rider moves the COG when making low speed tight turns, etc.

Brett is 100% correct. Stand up and you raise your CoG. But you add another layer of suspension - your legs.

@giuliobuccini208

2 ай бұрын

Almost correct. Suspensions are important, but it is a secondary aspect. I will leave you with an exercise: go to the supermarket and buy a big sack of potatoes. Then try to take it at your home by using just your motorcycle. Where are you going to put the load? In your side panniers or on top of your tail rack? 😎

@atticushexcel9567

2 ай бұрын

Or you could watch any Supercross race and notice how standing AS MUCH as possible is the proper way to greatness. As if ADV riding is somehow different d fro MX….😂

The most simplistic way to describe the benefit of standing I've found is to describe the bike as being like a horse. It naturally wants to stay upright, and by itself, its perfectly capable of doing so, what screws it up is the dummy on it's back. So, when the going gets rough, stand up to isolate your weight, the bike will take care of itself, as long as you can take care of yourself by keeping balance, and keeping steady gentle inputs.

@BretTkacs

2 ай бұрын

Absolutely true... Hence my brief introduction to unsprung weight

from my MTB racing times we always said the best rear shock are your flexing legs, and you just approved it, nice nice, V!

Bret, always good when you are trying to set the record straight! I wish teachers would start talking about INERTIA. That is the thing that makes the difference during active motion. Decoupling your mass from the bike's (by standing) results in a lower inertia of the bike (your mass doesn't need to move when the bike's moves, up/down OR rotating over obstacles). In relation to movement, inertia is the thing that matters, and is why a higher center of gravity makes leaning harder (same weight farther away from the contact patch takes more effort). Watch a figure skater in a spin - the farther out the arms go, the more inertia, and the slower they spin. Same mass, changing moment of inertia.

Great video! One of the first channel for adv riding !

as any >6'2"ft >110kg+ rider that's ever tried to ride a enduro bike standing up a techy hill when the application of power is required will know this first hand, unwanted immediate wheelstands are the result, for those of average and below ability anyway. Your video has helped my understand why I feel more comfortable standing on hills on the heavier 890 , even though my mass still rising when I stand, is a lower % of the total vehicle/rider mass.

Lots of physics, well explained, so we can all understand what's going on. Thanks, much appreciated, Günter/Nürnberg

Bret, you are perfectly right with your explanation, and if these people don't get it by now you shouldn't waste your energy on them. Love your content

Please Bret, release pods Even this, it will make everyone curious and watch it on KZread when explanation is needed 👍🏻👍🏻👍🏻👍🏻

There is another benefit to standing; moment arm of the rider is increased which translates into more stability (try balancing a broomstick, the tape a 3 pound wrench to the upper end and then try to balance it- it will be easier to maintain in a vertical orientation). Another bene; improved visualization of road detail (i.e. potholes and ruts).

@SethJayson

2 ай бұрын

This. Same with bicycles. I have a VERY low-slung recumbent bike (super reclined, butt about 6 inches of ground) and with all that weight down low, not far from the contact, and that super-short moment arm, the thing wants to roll over in a microsecond. Whenever the road surface gets hairy on that bike, sitting up is the first thing to do, the longer lever arm yielding an enormous benefit in stability. (with pedals in front, there's no way to use body to spring some mass, so the sole benefit is the longer lever.)

Great channel, great host, and pure information.

@BretTkacs

2 ай бұрын

Glad you enjoyed it!

The most important takeaway from this video for me is: "Whether we're sitting on the seat or standing on the foot pegs, the combined mass remains the same." Thanks Bret for another gem.

@BretTkacs

2 ай бұрын

The better lesson is that CG isn't what we should be focused on... Becoming effective sprung weight is what matters.

Here in an excellent lesson in basic physics and mathematics as it pertains to motorcycles, presented clearly and professionally. Thank you.

As usual, great rant

@BretTkacs

2 ай бұрын

Thanks Murrae

Sprung vs unspring is definitely valid, but I think that the increased moment of inertia is equally helpful. You can push the bike down further while counter-leaning to overcome sideways and off-camber obstacles, essentially becoming more "tip resistant". This is more noticeable at low speeds

Hey Bret, I do enjoy watching your videos, ranting, riding and everything else. My partner and I travel Europe 2 up and for the first time moto-camping, is there any tips, tricks or anything else you could suggest? We will be quiet loaded and going down some off road routes and camping grounds. A possible idea for Content maybe 🤔 keep up the amazing work 👍

Very informative presentation, as we expect from Bret. ;-) There is simply a dramatic change in the way the bike can be handled, and in the real results we get, when we stand properly. It’s worth a great deal of effort to understand.

@BretTkacs

2 ай бұрын

Agreed ... I have been ignorant about this in my past at one point as well as many others. The goal to stay open in our beliefs and willing to research, learn and evolve as riders. The more we understand the better riding becomes

@CurtisBrandt

2 ай бұрын

@@BretTkacs I had one recent ride, on a dry and low traction day, where as I got tired and sat down, the bike behaved way worse, losing traction at both ends. Back to standing and I could ride with confidence. Really opened my eyes. Thanks for all you do.

Thank you for this!!!

Exactly Bret

As far as i know another benefit of higher center of mass (or been taller on a bike) is that whole system needs more momentum to flip sideways and you have more time to react to this. I am not an engenier and can be wrong.

Agree. Like what I learned a long time ago, let the bike play under you. And about the legs as additional suspension is also correct which I also learned from professional down slope skiers. Notice how their legs play on high speed absorbing all the bumps.

As an engineer, I was highly confused when you said people think raising theirself *lowers* the center of gravity. I cannot fathom what line of reasoning would end up at that conclusion lol. Never the less, thanks for the exceptional explanation. Learned some stuff!

@Wollestar

2 ай бұрын

As another engineer, I think their reasoning is that you sit on the bike, therefore your main contact with the bike is the seat. When you stand up, the main contact is on the foot pegs. But they are mixing up cog and the application of a force. That also helps, because it is easier to balance the motorcycle on the pegs, compared to the seat.

@Kamel419

2 ай бұрын

I see, thanks for the explanation.

@BretTkacs

2 ай бұрын

This is the reason I wrapped it up with an introduction to sprung weight v unsprung weight

@etdbsub0

2 ай бұрын

As a baker, I was highly confused too.

@Steve-yu6pq

2 ай бұрын

As a social worker , I too was confused

Appreciate you Brett

@BretTkacs

2 ай бұрын

It feels good to be appreciated

All true, as far as up and down forces are concerned while going straight. One additional aspect of standing up not mentioned here is torque. (No, not engine torque, but the concept of force times length - of the lever with which a force is being applied, like in a torque wrench for example). Standing up moves the pivot point of the torque the body applies to the pegs, lengthens the leverage. This way the rider can apply more torque to lean the bike easier.

@BretTkacs

2 ай бұрын

This video was only intended to address one single myth... 👍

Thank you thank you thank you. I’ve been trying to tell my husband and brother in law this.

@BretTkacs

2 ай бұрын

🤣

Great stuff Bret... The COG stuff is common knowledge (I hope). Important to note that COG has no bearing on coupling or decoupling from the bike. The emphasis to me is that standing up is merely the act of decoupling your body from the bike. Using the term "standing up" is thus a misnomer and may add to some of the confusion. Yes, you do stand up to decouple yourself from the bike, but the goal is to decouple, not to stand up.

@BretTkacs

2 ай бұрын

Unfortunately CG/CM is not as well understood as you might think if you read through the comments on this video. I was trying to make that point. The argument is not that standing doesn't benefit the rider but must be done correctly and that changing CG/CM is not the reason for this increased sense of stability

I think a lot of this confusion happens because get people get the COG of the bike and the COG of the person is not specified. COG of the person does move upward when you stand, but the COG of the bike actually moves down. Think of a person sitting on a sawhorse with their feet off the ground and a scale underneath them. Their weight combines with the sawhorse and is applied to the legs of the sawhorse, but once you stand the weight goes to persons feet. Now if the sawhorse has pegs underneath attached to the frame then the weight shifts to a lower point of the sawhorse thus lowering the COG of the sawhorse. Because you stood up, your COG just went up, but separate from the sawhorse.

Yeah wow, never expected that one😂 A riders/bike center of mass is a constantly changing equation of speed, balance and weight. We can choose to amplify or counter our bikes suspension as it reacts to the terrain and speed in addition to any throttle or clutch application. Alpine skiers are able to write a similar equation with edge control at speed.

From my understanding, if you stand-up you do indeed raise your centre of gravity, but this only has an affect if the bike and rider are 100% vertical, it does not affect stability. It only affects stability when one moves the bike and/or rider from the vertical. Standing-up gives more precise control as even your head moving a few inches from vertical puts more weight to that side than it would if the rider was sat down (lever effect). Essentially, standing up allows a rider to fine-tune inputs to counteract the terrain more so than from sitting down. The legs also allow absorption of speed. Ride over a speed hump sat down, then try again stood-up, but absorbing the shock as you passover with your legs. Note the difference, and the maximum speed at which you can pass.

Also, by standing up on the motorcycle, the moment of inertia of the rider-motorcycle system increases. This results in a higher overturning torque required for the motorcycle to lean over, leading to greater stability

Very good explanation. Thanks for putting this together.

If you sit on the seat the majority of your body weight is on that seat loading the back of the bike. If you stand, the majority of your weight is at the foot pegs, the lowest point of the bike causing a more neutral balance front to rear. Center of gravity and neutral balance are two different things. Causing proper balance by shifting the weight off of the seat to the pegs FEELS like there is lower center of gravity due better control keeping the bike centered. Before this video I was fooled by how it felt like the COG was lower.

Physics is a hard subject to study and there are too many people out their with youtube degrees trying to explain university level dynamics problems to youtube university students who suck it all up cause it makes more sense to them then actual numbers and facts from credible sources. People will ignore truth if they can understand BS. Ranting is a lot of fun, thanks bret

@BretTkacs

2 ай бұрын

I maybe one of those 🤣... I've been wrong before and love being proven wrong because that means I learned something new. However when I ask for sources or calculations people almost always go dormant or refer to personal experience or hearsay.

@michiganmoto7687

2 ай бұрын

@@BretTkacsI always find it amusing how ,when asked for sources, the other person acts offended as if not taking their word for it is somehow personally offensive to them. 😂😂

@youtybebw

2 ай бұрын

you get there in the end but a few might might miss that actively moving body position is the key, just watch some motocross and learn

It probably comes from the bike feeling more maneuverable under you if you stand up, so COG feels lower but really it is just decoupling your body from the bike.

I agree with you. Although I never stand up while riding my CBR1000RR. 😉

So, you can more easily manipulate the weight of the bike and rider by standing which raises the mass weight on the pendulum?

Thankyou! I had spent 10yrs as an instructor and could not agree with the theory that standing up lowered the c.o.g. It made no sense to me, but it was the said thing (probably still is). I asked many a fellow instructor how could it be possible that if i attatched a set of stilts to my footpegs and stood 10ft in the air above my bike that my c.o.g. would still be lower than if i was sitting on the seat?

@BretTkacs

2 ай бұрын

I was also told to teach this incorrectly as an instructor. The Washington Motorcycle Operator manual distributed by the DOT still states this incorrectly. You states you should stand up to cross and obstacle because it lowers your CG. No wonder this myth won't go away 🫤

1000% agree. However, with the math, 25% understand

@BretTkacs

2 ай бұрын

🤣... I had to show the math to help minimize those who will continue to incorrectly believe this myth even with the facts in front if them.

could someone point me to where people are saying standing up lowers the c.o.mass.

The one thing Brett did not say is that regardless of CG not changing, there is a big difference in control of the bike between sitting on your butt in rough terrain and standing through the same, it is really accentuated in mud and ruts and hill climbing. Get your butt off the seat.

Hey. Would be cool to get your latest thoughts on the true 50/50 adventure tire. Is it still the e07?

@BretTkacs

2 ай бұрын

I have some tires lined up for review. The E07 is only available in limited sizes. The E07+ is NOT the same tire

I stand up when the terrain demands it or to see over an obstacle. The rest of the time I sit down. I don't know why this seems so complicated or maybe I'm just a simple person. I've been told the latter,

I have always thought that when standing on the pegs leaning forward or back wouldn't change the bikes center of gravity as the location of the weight doesn't change.

@rotorhead5000

2 ай бұрын

If your feet were in contact with the pegs in isolation, you would be correct. The ability to lean forward or back is dependent on either transferring some of tbat weight through your arms in either direction, or anchoring by squeezing with your knees and ankles, giving you a second point of contact with which to apply rotational torque either fore or aft. Try this to see what I mean; stand up on your pegs, no hands on the bars, and knees apart so as not o squeeze the bike, then try leaning forward/back. Then try doing the same while squeezing with your knees. Then think about what you actually do while riding.

@BretTkacs

2 ай бұрын

The reality is our CM is constantly changing as we move in any direction on the motorcycle. There is a much deeper conversation that can be had about load shifting too

Riding upright, in my mind, never had anything to do about the center of gravity and everything to do with using your body as an extension of the suspension. I may be wrong. Just the fact that one rides standing up doing tech sections on a MTB I think confirms my thinking, as a MTB is much lighter compared to a bike.

Even without understanding the math, it seems clear enough that if you build any structure taller and taller, you're going to raise its center of gravity higher and higher, too. I feel like a lot of this stuff has been known for centuries. Our ancestors relied on horses for this stuff until just a century or so ago. I have no equestrian education, but I would guess your modern ADV enthusiast could learn a bit from equestrian manuals on overland riding. The US was still using horses in WWI, so there should be some practical guidance there, to start. I'll look into it. Maybe somebody else already knows about this stuff and can tell me. Regarding your sound setup, I know that a simple panel of acoustic foam standing right behind your mic (or behind the camera, since you're talking towards to the camera) can help attenuate a lot of noise. Mo' foam = mo' betta. You've got a big space to work with, but a little judicious panel setup can probably help. I heard your filter cut on early in the video, and that helped a lot, too.

Just going out on a limb here.. weight & balance pun intended.. commenting before I actually watch the video 😀 CofG = single point in any object about which it is perfectly balanced in all directions; □ motorcycle has a CofG □ rider has a CofG □ Add rider to motorcycle; result is a combined center of gravity or CCofG; Standing up raises the CofG of the rider, which in turn raises the combined CofG (CCofG) of the motorcycle and rider, which essentially have become one unit once the rider has climbed aboard. Pilots & forklift operators understand that there is a horizontal component as well as a vertical component, each with prescribed limits not to be exceeded regarding whatever equipment is being operated. Now I will watch the video to see if my correctness, or lack thereof, is within recommended limits. 🤗

It turns out Gumby is a good rider when standing off-road. Pitch and roll momentum are good for tight lines.

You stand to lower where you apply your weight: pegs instead of the seat.

@XxAdminChllaxX

2 ай бұрын

Yes, and to be able to temporarily become weightless.

@dtrex392

2 ай бұрын

Where the weight is ‘applied’ doesn’t make a difference when we’re considering the entire sprung weight, which includes you the rider. If you stand up, the center of gravity of the whole system (the sprung bike + you) becomes higher. Bret is right on this. And I’m a mechanical engineer who understands free-body diagrams. 😊

@dougnash6316

2 ай бұрын

Yes, The bikes center of mass doesn't change but the riders center of mass changes with input. If you sit, its higher than if you stand. We have input on our handlebars, seat and foot pegs. A rider has the ability to change the bikes attitude, actively. If a bike is tall and heavy, you cant change that. Rider input is key.👍👍

@dtrex392

2 ай бұрын

⁠@@dougnash6316Standing RAISES your center of gravity. Your feet and butt contact points have nothing to do with center of gravity.

@zugmeister314

2 ай бұрын

Think of it this way: If you were 6' tall and your upper body were exactly as heavy as your lower body your center of mass would be 3' off the ground when you're standing upright. That center of mass remains in the same place on your body regardless of whether you're standing or sitting (until you raise your feet over the height of your waist but let's not go there). So is that midpoint higher or lower if you're standing on the bike? It's higher because you're standing. Now you're standing on the bike so the center of mass of you+bike is now higher than it was when you were sitting.

You're all wrong, you stand up to save your kidneys from being smashed.

It's quite simple: Ask the people what happens with the cog of just the bike if the rider changes position. Of course it doesn't change. Now ask what happens with the cog of just the rider if he stands up. Of course it will lift. Now how can the stand up of the rider result in a lower cog if the only change is a lifting cog?

Is this the best April Fools' Day joke or what. Sure got me.

If you try to take your foot off the pedal when you are standing, the motorcycle becomes completely unbalanced. Now when you are sitting on the motorcycle seat, you can easily take your foot off the pedal. This means that the weight is actually lifted off the pedal when you are standing.

This one will endlessly be debated until we can very clearly define ‘the system’ being analyzed. Is there just one spring and one unsprung weight (one system), or two springs and two unsprung weights? (Two systems). Meaning, the rider is a separate system with his legs being the springs. If it’s the latter, the rider is actively using his legs to dampen his weight, then the force on the pegs varies with the terrain. The center of gravity of the bike is now varying all over the place, and discussing what this center of gravity is seems to be a silly discussion. If it’s the former, then standing up is simple physics and the center of mass of the bike + rider is now higher. Just like the center of mass of kids on a merry-go-round, or figure skaters with limbs outstretched suddenly tucking in when doing a spin.

@BretTkacs

2 ай бұрын

When I do these rants I try to clearly isolate the question. In this case it was about CG/CM. I even concluded what I believe is the most likely cause for this misbelief. There can only be a debate if riders ignore the facts.

@dtrex392

2 ай бұрын

@@BretTkacsI agree 100%. My comment was directed more towards your viewers, I wasn’t trying to criticize you, though in the end it wasn’t quite clear enough. If you stand up and your legs are absorbing much of your body’s weight, it’s really TWO systems, 2 CG’s. You have wheels, suspension, bike, legs (suspension #2), and your body. It’s 2 stacked systems. Or if you’re sitting, or rigid on the pegs, it’s one system, one CG. That’s where people’s viewpoints differ. And that’s difficult to communicate!

@C_R_O_M________

2 ай бұрын

@@dtrex392 it's more like the system, as a whole, becomes more like 2 systems when you stand up but it never completely reaches the 100% 2 system status as there are always attachment points (handlebars, pegs) involvement and those, inevitably, create a whole system (which is more dynamically efficient and less prone to instability than when you sit). In other words, we help the bike do its thing under us when we stand up but, at the same time, we can't become 100% weightless either (which, sometimes, works in favor of the system as a whole, by counterbalancing forces with proper body positioning).

So, standing on pegs doesn’t lower center of gravity but does rise control and balance?

@BretTkacs

2 ай бұрын

Yes

So the” rant” was something that is very obvious, and I dont know anyone who would have doubted the benefits of standing up to absorb shock. Note: there was no “sign language” gestures for the deaf, the presenter just has a family trait that he thinks makes no difference in how his communication is received.

👏😊

I've always thought that the only bike where you'd spend most of the time standing is a trials bike.

Almost there. "Suspensionicity" is an aspect, but not the main one. Comment from rivernet62 nailed it: "the rider is decoupled from the bike". There is no rigid connection between the two bodies (bike and rider), so talking about COG has no sense. Just simply geometric aspects are predominant here. Think at the rider as a sack of potatoes transported on a motorcycle. Where you would put that load? On top of your tail-rack? Or would you distribute it in your (lower) side cases? The matter here is just one: the location of the point where the gravity force is applied. The higher is the point, the more unstable is the configuration. That's all.

If standing lowered the c of g wouldn’t MotoGP bikes corner with the rider standing?

@BretTkacs

2 ай бұрын

Having the lowest CG isn't the goal. For MotoGP it has to do the the rotation or the pivot around the CM. Closest to the center of the bike is better than one lower on the bike. Low CM is very good on low speed situations like u-turns or balancing (think HD or trials bike)

Leverage baby

Example with a 100 kg pilot Hypothesis 1 - I am sitting on the motorcycle, my weight exerts a force on the motorcycle saddle. In this way we ride the motorcycle using our butts at the saddle and handlebars. Regardless of the position of the rider's center of gravity, the coupling of the rider and the motorcycle takes place on the motorcycle saddle. Attach a 100 kg weight to the motorcycle saddle and try to lay the motorcycle on its side, and lift it. Hypothesis 2 - I am balanced on the pegs, our weight exerts a force on the pegs. This way we control the motorcycle with our feet and the handlebars. Regardless of the position of the rider's center of gravity, the coupling of the rider and the motorcycle takes place at the height of the motorcycle's footrests. Attach a 100 kg weight to the motorcycle pegs and try to lay the motorcycle on its side, and lift it up. Which of the two hypotheses is easier to balance?

@BretTkacs

2 ай бұрын

With example 1 you are starting that standing on the seat is the same at sitting or laying down on the seat. That the CM is irrelevant and it is only the drive of Gravitational thrust that matters.

@alainmaurice5383

2 ай бұрын

@@BretTkacs Thank you for the explantion

This myth and why I stand up on my "adventure" motorcycle is basically reminiscing about younger days of me riding my BMX (motorcross-like) bicycle when I was 10 years old. That's it really. Other reasons are just BS.

@bret sounds like you know your physics… thanks for the rant-splainer!

The mass being you is weighted on the contact point. If you lean to the side than you raise your center of gravity if you go slow enough to tilt the bike. However if you stand perfectly straight your weight is added to the pegs thus adding more counter weight to the fuel tank (on typical bike - not gs/ktm 890…) this lowering center of mass. Of course if the bike tilts right or left you have to counter steer with body. If bike lean left you need to press more the right peg. So your claim is correct but not truely as center of gravity is lowered if acting properly. Of course vs sitting when the weight is mostly on the seat and thus higher…

@BretTkacs

2 ай бұрын

Weight doesn't work that way... Again you are mixing CG (weight) with sprung weight

All this yak, when the question is: how do you use rear brakes and shift gears when you stand on your toes....Wayyyy more important for an average driver. The minuscule change of center of gravity....like a full fuel tank? What about the better overview? Or bounce right off the bike when the riding gets rough...Would I fargin care? Buy a Beemer, it has a low COG...😂

Bret, thank you for all your content, but I got to chime in here. You are correct, but also wrong on the CG demo. It's how you consider the frame of reference. You are correct when you consider the bike and the rider as a complete system. If you have a CG height of the bike that doesn't change, and you have a CG of the rider that depends on riding position, you raise or lower you system CG as the rider stands or sits. Assuming the bike and rider are an attached ridged structure, this affects the Moment of Inertia of the system. As the CG of the two separate, the bike gets more "stable" or harder to roll about that axis. Think of the whole spinning skater demo and as the skaters arms come in the skater spins faster. To continue the analogy, we are in essence, "Extending our arms" when we stand up and allowing the bike and rider system. to more stable about the pitch and roll axis. However, when you look at just the forces on the bike it depends on where the weight of the rider is applied on the bike. If a rider is sitting, 90% of the weight of the rider is applied at the seat height, when the rider stands, 90% of the weight is applied on the foot pegs. Sum the forces on the bike at the location they are applied and that's why they say the CG lowers when you stand. The motorcycle only knows the forces acting on it. This is also why we all learned to pack heavier items as low and as close to the center line of the bike as possible. So, yes, but not the whole story.. Will say you are spot on for the sprung and unsprung mass. Thanks for being a great advocate for the sport and I hope to one day go on one of your trips.

@BretTkacs

2 ай бұрын

I felt I clearly illustrated that united effect and even addressed one of the reasons why standing has a sensation of lowered CM. When I rant on topics like this I try to isolate the single question to address rather than making it more complex, same as my talk on air pressure vs footprint. I never said there can't be value to air pressure changes I just said if increasing air pressure is the goal it has no useable change

You lost me at "welcome". 😛

Hello, the fundamental concept of not changing center of gravity seems to be correct, but calculation regarding center of mass not correct, specially in first example the first subtraction ==-1, which is conceptually wrong !!!

Yu Wong Too. 😂

Pretty obvious that you center of gravity is raised. What you do is add a hinge into the system so that the entire mass doesn't need to move.

Where did you get the equation? It works with it feels to me that the center of mass would be calculated horizontally versus vertically. I’d have to look it up.

@BretTkacs

2 ай бұрын

CM is position neutral. It doesn't matter direction. Think of doing the calculation in space where there is no direction

This is why I argue that people should study a bit of physics when they learn how to ride a motorcycle. If they understood how the motorcycle actually works they wouldn't sound like an idiot all the time. Read through any comment section and it makes you wonder where all the inteligence went that got humanity where it's at, that is very sad. We need more critical thinkers.

Hey me and you will go on an enduro trail ride . I will ride my bike however I choose to ride ( standing/sitting) all you have to do is ride with me sitting the whole time. Record the whole ride so we can upload the results instead of you jawing in front of a chalk board. Let me know!

@gzahnd

2 ай бұрын

Hey everybody, I found the tough guy right here!

@Matthew-wn8oq

2 ай бұрын

@gzahnd oh is that you pole smoker? I knew it! How ya been ? Haven't heard from you in a while flamethrower

@gzahnd

2 ай бұрын

@@Matthew-wn8oq Tough guy challenges to the educator, and name calling otherwise. Cool, bro. Honest question: why go out of your way to be negative to someone who is a world-class educator teaching those who are interested? Does it feel good to you to be this way?

@Matthew-wn8oq

2 ай бұрын

@@gzahnd well pole smoker , he has no clue what he is talking about and your a dip shit for listening to him. How's that? There is no way to ride offroad even moderately fast while sitting on the seat. He can't do it , you can't do it and Graham Jarvis can't. If you road your Honda cb750 on the street all day , you would be fine. I'm done talking to morons. Have fun out on the trails with your new found " genius" offroad riding education. 🤣

people just need to learn how to stand 1st and foremost - you are not meant to be a lamp post, pivot at the hip and stick your arse out, give the bike and yourself a chance

I need to go back to the issue of weighting the pegs. RyanF9 sort of poo poo'd the thought. I think his conclusions might be wrong though. He showed, in isolation, you can't turn a motorbike simply by shifting weight on the pegs...but it's a commonly taught dirt/adv technique. I think it works in conjunction with your body weight/handle bar pressure.

@BretTkacs

2 ай бұрын

You can steer at the pegs without touching the bars however I also "poo poo" the concept of peg weighting. It's not actually weighting the pegs it's about relocating the CM to cause or shift stability. A deeper talk then I want to type here

It's a bit less exact than math can describe. We are big floppy meat bags, not a solid weight base. Sitting adds our mass to the bike proportionally to our position. When we stand, we move our mass to a vertical pivot point based on how we move. We can position ourselves to improve that weigh balance or make it worse. Making it better is what our brains will naturally do. Making it worse would take effort or complete incoordination.

@BretTkacs

2 ай бұрын

It's exactly math... As long as we are body is moving on the bike (sprung weight) the CM is constantly changing however at any give point there is exactly point that can be calculated for CM

Common sense isn't so common for some? 🤦

If you were in a full body cast, with your feet, strapped to the pegs, and your hands, strapped to the bars, you would be correct

Come teach us in Israel, please ❤

@BretTkacs

2 ай бұрын

I have tried twice but both times didn't pan out 🫤

A little high school physics is a good thing.

You missed your calling…. You should be working on a Billy Graham telethon….

Your legs are springs. Nobody stands on their pegs in a ridig state and survives. 6.54

Are there still people out there, who do NOT understand the basics of physics? Probably those without a decent school education.

When I'm sitting on the bench, most of my weight is concentrated on the bench. When I'm standing, 100% of my weight is on the pedals, right?

I can't believe this is really a myth. How a person can think standing lowers your CG is beyond me and such a person surely can not function well in society. I am baffled.

Ok take out the math it’s for the keyboard warriors , riders stand up and seat regardless. Up and down we go , the whole time I’m smiling 😊😊😊😊😊😊

One benefit is easyer to fart! Jus saying

🥱

The simple cause you should be telling is that when we stand up while riding it isolates the riders mass from the moving engine mass below which makes it easy to find its true trajectory. You've gone into too much detail to explain something which you know is right. The thing with technical definitions is you need to define everything you use, which you don't here, which leads to more confusion actually.

stopped at second 20. riders don't stay upright in offroad to reduce center of gravity, but because they love their balls! nonsense discussion here

Please get out of the classroom and on your bike! 😉😘

Why don't you show them with a bike instead of a chalk board, put a bike on two heavy duty scales one under each tire and show the math happening between the two.

The problem is people have completely lost their critical thinking ability.

@BretTkacs

2 ай бұрын

It's the backfire effect of confirmation bias

@MrRickrm

2 ай бұрын

Another great video, Bret. Your other video, weightless rider, comes into play here, I think, to keep my cm in the right scheme of things while the bikes does it's bouncing around.

Here is an example *most can understand, no math involved. (*most is an overstatement nowadays). Most are probably familiar with the cheetah, the fastest land animal. It has a thick and long tail which it uses as a counter balance when zig-zagging at high speeds. This is exactly what one is supposed to be doing when standing up offroad. We are NOT supposed to be standing up stiff like a dead log, we are supposed to be using our bodies as a counter balance. Just like the the cheetah's LONG and thick tail alters the center of gravity of the animals speeding body, that's exactly what our bodies should be doing when standing up. Raising our bodies, raises the center of gravity thus giving us ample of leverage to counter balance the immense weight of a moving motorcycle! Anything contrary is plain old stupid.

@tonyhaddon2582

2 ай бұрын

Yes but what about the whiskers ?

@SsiolisP

2 ай бұрын

@@tonyhaddon2582 think of them as parking sensors!

P.S. standing has very little to do with "lowering center of gravity" its about letting the bike move under you where it needs to go while using your legs as an extension of the suspension. The way you speak and no offense sounds like you have very little experience racing or even riding enduro off road. Just sayin.

Not really correct - if the body would be "glued" to the bike then one could argue like that. But the issue is that we never ride like that. Even if it is learned that the legs have to be tugged to the bikes tank, it's just not exactly the same. And if we talk of off-roading / standing - exactly the issue that the body is decoupled from the bike and the gravity >forces And if you sit, then the calculations you have done apply much more .. combined COG much higher then bikes' ... 🙂 ... and that is why we stand up.

This is like having a conversation with a flat-earther about the shape of the world, LOL! What's the point? You can't win an argument with someone who is irrational, it's an exercise in futility.

@BretTkacs

2 ай бұрын

Unfortunately your point is validated by several of the comments

I've never heard anyone claim that but I guess we can thank teacher's unions for creating a scenario in which anyone would think it necessary to teach that raising a mass raises center of mass. 😕 Your sound is fine, BTW.