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Mark Hinchliffe·
Tips/trainingRiding/safety tips
··14 Comments·3 min read

Does standing lower a bike’s centre of gravity?

Husqvarna 650
Husqvarna TR650

Many rider trainers have claimed that standing up on a motorcycle lowers the centre of gravity and makes the bike more stable, especially over rough, loose and slippery surfaces.

The statement about lowering the centre of gravity has caused a lot of argument among riders and those schooled in the laws of physics.

Riders claim the point of contact with the bike is lowered from the seat to the footpegs, therefore lowering the centre of gravity, while physics students say that standing up actually raises the centre of gravity because the rider is so much higher than the bike.

These are simplified explanations for the two arguments, so we asked Former Triple 8 engineer and now race engineer for the winning Porsche Le Mans team, Jeromy Moore, of Brisbane.

“If you consider both the bike and the rider as a rigid object then no. It raises the centre of gravity,” he says.

“However, when standing you are not a fixed object on the bike.

“The main point of standing on a dirt bike is the ability to quickly transfer the rider’s weight from one peg to the other which makes the bike respond quickly.

“It gives the rider more control over the bike’s mass which gives the perception of a lower centre of gravity when, in fact, it is the opposite.”

There are other good reasons to stand up while rid9ing on rough surfaces.

BMW Motorrad GS Off-Road Training

ONE

The most important reason for standing up on rough terrain is that it increases your vision ahead. That allows you to avoid obstacles such as potholes, rocks or mud, or to pick a better path so you don’t end up in the deepest rut, or to see whether there are oncoming vehicles over the crest of a hill.

TWO

Your legs become “part of the suspension”, so a sudden and large bump doesn’t jolt you off the bike as your legs absorb some of the impact. Remember to keep your knees slightly bent.

Water crossings

THREE

It divorces the jostling of the bike from your body weight. If you hit a rock or momentarily lose traction – such as in a water crossing – and the bike kicks sideways, it is mainly the bike that is moved, not you as well. Therefore you are less likely to be bucked off.

FOUR

A rider sitting on a bike tends to overreact to every sideways movement of the bike. Standing up divorces you from all these minor movements so you aren’t worried by every buck and weave. It also allows the bike to do its own thing without the distributing influences of unnecessary and reactionary handlebar corrections.

BMW Motorrad GS Off-Road Training

FIVE

Standing also gives you extra control over the bike with your feet.

Try standing up on your bike and concentrating on not putting any steering or counter-steering pressure on the handlebars.

Then move your right knee slightly forward. This puts pressure on the left footpeg. Notice what happens. The bike will swerve to the left.

I’ve seen the video where a rider holds a bar on the tank so there is no steering input and tries to steer the bike by leaning. It hardly moves.

If they tried holding on to the tank while standing and moving their weight on the footpegs they would find the bike does turn. Unless you have a handle on your bike, I wouldn’t suggest you try this as the bike will swerve quite suddenly, such is the effect of pressure on the footpegs.

Sitting down and putting pressure on the footpegs doesn’t have near as much effect as when you stand and put your whole body weight into a footpeg.

You can use this pressure on the footpegs for steering the bike, but also for adding traction when the tail is sliding out. (Place you weight on the footpeg on the side the rear wheel is sliding toward.)

Steering with your feet also means less handlebar input is needed and less reliance on front wheel traction.

BMW R 1200 GS safety recall
BMW R 1200 GS

If you do stand up, you may need to adjust the clutch and brake levers for the different angle of your wrists, and the gear shift and foot brake levers for the angle of your foot. You should also adjust at least one mirror for better rear vision.

WARNING

Be aware that in some jurisdictions, standing up on the bike may be illegal.

Most Australian states now allow the practice, but be aware that it is specified that it is only for negotiating rough or slippery surfaces.

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Mark Hinchliffe
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14 Comments

  1. Well investigated and written article. I race and ride on road and dabble in dirt. Your article is spot on. As a past pupil of CSS I was going to cite the “no steer bike” but continued reading. It seems to me that as a low centre of gravity is important in road racing (to keep the bike upright) that it is not always advantageous when riding on a loose surface. Good stuff

  2. Interesting discussion. I read a article recently that recommended to sit, lean forward when doing a lot of hillclimbing, to preserve energy and bring forward the centre of gravity. Ive tried it and when the trail wasnt too rough. Seemed to work well. Not confident that I would try it on a real rough track though; I think the leg suspension of standing up and forward would still be better for that.

  3. As long as the rider is attached to the bike, seat, pegs or otherwise, and only the tyre contact patches are contacting the ground, it is absolutely 100% impossible to lower the CoG, or more accurately, Com (Centre of Mass) CoM by standing. It just does not happen, the CoM is RAISED.

    Of course in this situation this is a good thing as we know, RAISING the rider’s CoM, and therefore the combined rider/bike CoM:

    · Provides more leverage on the bike. As the masses are spread further apart stability is improved. As the masses are centralised, a bike is less stable, and steers/manoeuvres more responsively, witness sportbike development over recent years

    · Decouples the rider from the bike to allow for the riders’ CoM to move independently of the bike’s CoM with often only the bike deflecting, or the rider/bike combination deflects less than it otherwise would, assisting correction

    · Adds suspension through the knees, so less combined deflection again, and easier recovery

    · Improves visibility to better anticipate and plan earlier

    · Improves ability to move the body mass fore or aft, and therefore the CoM to keeping the body’s CoM within the bike’s wheelbase to suit up or downhill

    · Adds the ability to preload the suspension to assist with obstacle negotiation

    · Moves the raised CoM left or right to suit the terrain, ie cornering or sideslopes

    Lots of advantages to standing at the appropriate time, but it is physically impossible to lower the CoM/CoG. Its not a matter of opinion, its just PHYSICS.

  4. Stitting is a single mass (or strongly damped two mass problem with the rider pivoting and sliding about the seat) problem.

    Standing converts this to a lightly damped two mass problem. The overall centre of mass is higher, but that of the lower mass (the bike alone) is lower than the combined centre of mass when sitting.

    A low centre of mass is stable. Cruisers have a low centre of mass. They are not good race bikes. The higher the centre of mass, the less lean angle is required for a given corner radius and speed. Note the spectacular failure of race bikes with exhausts over the engine and fuel underneath as the centre of gravity was too low. The theme now is mass centralisation, that is as much mass as close to the centre of mass so that the moment of inertia is smallest and thus the bike requires less force to change orientation.

    Weighting the pegs is a technique that encourages a rider to move their centre of mass, furthermore such motion often imparts a force through the bars, which causes the bike to turn. Often riders are unaware of the slight pushes they make on the bars

  5. Two important points; 1) This is all about dirt riding techniques. Occasionally standing up maybe useful on the road, but generally it is only done by dirt riders and adventure riders. If you only ride on roads you probably won’t understand it. 2) We are not talking about the total combined mass of the bike and rider, but the mass that can make movements that are, to some degree, independent of the rider.

    When standing up the rider’s mass is no longer rigidly fixed to the bike. The important part is that his mass is pivoting, and it is applied to the footpegs. If his mass was pivoting on the seat the CoG would be higher. This is applicable to the rocking back and forth, and side to side movements that the bike can do independent of the rider.

    Example 1) If you were riding off a 300mm high rock ledge at low speed you would crouch a little over the handlebars. When the front wheel drops off the ledge you would extend your arms allowing the bike to rock forward without you body rocking forward with it. Then when the rear wheel drops off the ledge you would allow the handlebars to come back towards you as the bike rocks backwards. Example 2) Watch a motocross rider going flat out over a section of whoops. The bike rocks back and forth while the orientation of the rider remains fairly constant. In both examples, if the rider sat down the rocking mass would be greater and it would be higher. These are the types of things that riding instructors are referring to when the say that standing up lowers the CoG.

    Students at riding schools have to take in a lot of information in a short time. The instructors don’t want to overload the students with unnecessary complex explanations. What they are saying is appropriate for what they are trying to teach. But often someone who wasn’t there hears about it and takes it out of context, misapplying the laws of physics to the situation because they don’t have any understanding of dirt riding techniques. In other words, they may understand physics but they don’t know what they are talking about when it comes to dirt riding.

    This issue arises more often lately because in recent years a lot of people have taken up adventure riding without having any dirt riding experience. When they come across any challenging terrain they sit down so they can paddle with their feet. If you explain to them that it is much easier standing up they will disagree and say that sitting down lowers the CoG making the bike easier to handle. They are not willing to admit that they are lacking in riding skills.

  6. Good article, Mark, but there is a couple of things I disagree with. 1) The advantage of standing up to lower the CoG (yes I know the pedants call it CoM) is not for stability as much as it is for manoeuvrability. The bike can make movements without taking the full mass of the rider with it making the bike more responsive. 2) The extra visibility gained by standing up is important but the most important reason is to use your legs as suspension.

    Another advantage of standing up is it allows you to easily leap off the bike and hold it up instead of falling over. This is particularly useful in water crossings to prevent drowning the bike. You often see riders sitting down and paddling with their feet. If the front wheel hits a submerged rock the bike flicks sideways taking the rider with it and the whole lot ends up in the water.

  7. Very well explained guys.
    I have been preaching the “compass” method, as I call it, for years now to any motorcycle newcomers.
    Bike rocking north to south (rough terrain) – standing up helps by giving the bike a little more freedom in movement with the added bonus of greater control options.
    Bike rocking east to west (smooth, normal terrain) – body close to bike, so you become as one with it, great for high speed manoeuvrability such as when transversing in traffic and high speed cornering.
    Whether I am right or wrong, to me I feel that when I am standing I am not so much as lowering my CoG but just lowering my north / south pivot point, (pivot on my feet – not my butt), but I dont think I would like to throw a screaming DRZ450 into a 90○ turn while standing, might hurt.
    At the end of the day your body and bike become as one and you do what is needed without a second thought as to the science of it all.
    I hope you dont mind, but I would like to print this article off to be shared for comment at our next bike trip/get together.
    Stay Safe.

  8. Standing on the footpegs is RAISING the centre of gravity of the Rider/Bike combination. Those that believe otherwise are mistaken.
    As for giving all the benefits as stated in the article above and those benefits I have heard over the years, it may well be the case. I am happy that they are riding in a way they feel comfortable and in control.
    When I have seen riders standing on the footpads it has been on tar and not rough & broken ground.

  9. i am definitely of the in favor of standing , over rough ground i think the key to the theory is that the mass of the bike and the mass of the rider are able to act to a degree interdependently thanks to some of the best suspension ever designed (legs). As for weighting the pegs to assist in steering the bike, if your not doing it you are not using all the resources available to you, like driving a car but only being able to turn the wheel 3/4 the way round. if you pegs are directly below you or behind you the difference is amazing but even on a a cruiser with slightly forward controls you can feel the advantage

  10. Interesting article. I remember spotting a rider standing on his bike as he rode down a rural road doing about 40-45. Not familiar with dirt bike riding I thought the act dangerous and, well … showy, if not stupid. After reading this article I see where the rider was coming from. However, I’m not convinced that it’s an option to the traditional practice of sitting. If one is riding off road, or on a poorly maintained road, one filed with road hazards, an unleveled camber, potholes, etc. … I can see it being used.

    But we sit for a reason — it’s more comfortable, and it preserves our strength. No one wants to stand for a given length of time. If I see a pothole I will half-stand in my seat to take the shock of the bump, but I return to the seating position. Sitting distributes your weight on the seat and to the foot pegs/running boards. If you’re standing, hit a bump and your foot falls off a peg — you can see where this is heading — or crashing.

    Last, the ideas of shifting, and applying the rear brake while standing/riding weren’t discussed in the article, nor what happens when leaning into a tight or sharp curve while in a standing position, or applying the brakes while standing and turning.

    I’m an animator. We animate characters walking which means fully understudying the body’s center of gravity and how it leads the walk. Unless a person is very obese, or juts their hips out, the center of gravity on most people is located in the head when standing. If crouching it shifts lower, but the higher you stand, the higher the COG. When the head tips out so that the legs/feet are not under it you lose your balance. Is this counter-balanced by the bike’s movement, or the centrifugal actions of the wheels if one is standing? How do you compensate in a strong turn? Also, how does the body respond to a cross wind, or does it increase the bike’s sail when standing?

    It seems idea for rough terrain, but I wouldn’t call standing a breakthrough alternative to sitting where you are more one with their bike. The article has a lot of pros, but I’d like to hear the cons — or the other side of they coin.

    1. “center of gravity on most people is located in the head when standing”

      Really?

      The centre of gravity of a material body is a point that may be used for a summary description of gravitational interactions. In a uniform gravitational field, the center of mass serves as the center of gravity.

      So whether a person is standing or prone, the centre of gravity of the person is unchanged.

      By your explanation, therefore, I should be able to place my head on a kitchen benchtop and extend my body horizontally, with all weight acting through my head, (the ‘centre of gravity’) and not fall to the ground. Hmmm – it’s not going to happen.

  11. The COG is raised, but the riders weight will now be 90% on the pegs, so the weight is lower, good for control via arms and legs which give quicker movement than sitting which holds the bike with the bum planted.

  12. The Centre of Gtavity woukd only raised if the rider was ridged/fixed on the bike, but as the idea of standing is to allow the bike to move around beneath you freely, the CoG is actually lowered because your seated weight is no longer included in the CoG calculation.

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