Archive of BMW Motorrad Club Cape (2006 - 2019)

Cliff, Standing up is not recommended on a cruiser ;-) I'm only standing up because my 650 seat is so darn uncomfortable ;-) Corné Kloppers http://www.bikepics.com/members/pantsula/07f650gs/ 0849130391 ckloppers@gmail.com

When you are on a large dual purpose bike, your balance improves when you stand. There are a number of reasons for this including a lower centre of gravity (weight moves from saddle to foot pegs) and the fact that humans' balance comes from their feet not their bum. You also have better vision which improves your ability to manage the bike ... offroad the rule is Head Up, Stand Up, Open Up (Open up being a case of opening legs so the bike can move under you while you do the balancing, as well as the use of measured throttle increase). All this becomes habit after a while and when one experiences a difficult situation it becomes second nature to stand. I often just practice balancing while moving slowly such as at a traffic light or at the rear of a convoy during a breakfast run. This is probably what you are seeing riders do. Either that or just getting comfortable. It's nice to be able to stand for a while instead of sitting and it's pretty comfortable on a dual purpose bike. Of course if it was Neil you were looking at he wasn't actually standing ... he was riding next to Jane. He's 6 foot 13 inches and Jane is 4 foot half an inch ... optical illusion. :-) ''If you can dream it you can do it!''

Still, not exactly required on a dead straight tar road. No wonder the KTM blokes mock the BM riders..... Lawrence (OK, I'm stirring now!) Life is not a journey to the grave with the intention of arriving safetly in a well preserved body, but rather to skid in broadsides, loudly proclaiming WOW, What a RIDE!

Well the KTM blokes mock us cause they look stupid while standing, and we look cool. I don't stand on a straight tar road, unless I'm trying to cool off or stretch my legs.

I also stand to stretch my legs, get a better view in traffic, or cool off - works like a charm :)

The KTM guys can't go so far on one tank. That is why their bums don't get tired and they do not have to stand.

Cliff, don't be phased by the idiots standing up on tar roads. 10/1 its that idiot Andy on his GSA, he can't be helped, people have tried. He stands up all the time and will probably sell his seat one day as "brand new". Don't try that on tar. Even the cops have given up on him. They ignore him. And that rediculous smile on his face has been there ever since he bought the GSA. Ignore it, don't even wave..... Andyman Yup that's me. Standing up in the traffic on the 1150GSA.

I don't ride a bike to look cool. I ride a bike because I love it. If I stand on straight tar, I'm not going to let anyone talk me out of it, I'll stand cos it '''feels''' cool. :-) ''If you can dream it you can do it!''

Most of us who ride dirt understand how we can control the bike from the standing position in relation to when being seated. I dont want to go to far into the dynamics here but bear in mind that there is a subtle difference between "standing position and "correct body position". Still dont understand why the one should "open up your legs" and I dont refute or question the instructors as they do great work. On the contrary I would appreciate if Leon or one of the others involved would be kind enough to explain the theory and reason behind this. When I ride tar or dirt I grip the bike with my knees so that there is less chance of my legs being slapped of the pegs and to rest my hands and upper body and minimise arm pump. The ergonomics of the bike, (handlebar to footpeg distance etc) also factors hugely in how you naturally position. Its a lot harder on some road bikes as your balance is thrown out of whack. Easy way to determine, stand up ,ride in straight line, remove one hand from bars. (proceed with caution please, on a road bike this may be more akward than you imagine). I am a professional I have been doing this for years and nobody has been hurt, ERR MUCH OK. 1)I stand out of habit. 2)Because my "broek" then tends to drop down and end up as it should be on my body. 3)To show KTM riders my arse ass I outride them. 4)To change COG and control. 5)To moderate grip to the backwheel. 6)To enable me to place more weight and force on the pegs. 7)To allow my body to become part of the suspension. Theres more of course, isnt there always. Hope you all had a great day. I RIDE THEREFORE I AM!

I think maybe opening up your legs is so that you don't clamp them to the bike (like a death grip) in a hairy situation - and that you don't shatter a bone in the process :) I also use my legs closer to the bike than suggested - I find this works for me. But heck - I'm a novice - I spend more time tyres up in the sand than actually going through it :P - maybe one of the "men-in-the-know" can share the tech on why this is done? BTW - in the sand - I keep my legs wide open - I find that it doesn't bruise when the bike thrashes side to side as she does sometimes going through.

Hi Freak ;) I think what the instructors are trying to get across is that the rider should 'decouple' themselves from the bike by allowing it to move around underneath them, instead of flinging them from side to side. For a professional this comes naturally, and you couple and decouple (sounds dirty) from the bike as the situation warrants. Also, with a light moto-X bike you control the bike. However, for us old-ballies riding monster machines that are up to 4 times heavier than us, when we hit rough terrain and the bike needs to go with the flow, the training is geared to teach us to relax and let it. The basic training starts off by instilling a sense that the bike 'wants' to do the right thing, and the less we interfere with it, and the more relaxed we are, the better for us both. I suspect the training on the 450s will be quite different!

Dear Peter Remind me to not ever go flying with you ;-) When you stand up, your weight, and your centre of gravity, goes up. As does the overall CoG of you and the bike. What changes is that you now have control over which side of the bike you want to dangle that weight because you are on your feet and can lean your weight to either side. Website Administrator [http://honeybadger.net Honey Badger IT Services]

Dear Webmaster, interesting! Your sarcasm deserves a response. CoG is the ''average location of the weight of an object'' and weight is mass times acceleration due to gravity. Bikes and aircraft can't be compared as an aircraft rotates around its CoG, whereas a bike has a bridle point, being "attached" to the ground. A bike also has a mobile intelligent (debatable :-) ) mass onboard. Weight always works through the CoG. If we adjust the weight we therefore adjust the CoG. If you stand your position moves UP so CoG should go up IF we were fixed to the bike, however the application point of the weight moves down and the bike leans so it's no longer a 2 dimensional situation and other forces come into effect which shift all the averages around (explains the Open Up concept). For a non uniform mass operating in 3 dimensions, a triple integral is required to assess the effect of the mobile mass in the three planes, x y and z, resulting from the average position of the mass given the influence of gravity and its density. Here's a series of diagrams that I found elsewhere on the web that helps explain : | <--- rider | <--- motorcycle The rider is directly above motorcycle. The center of mass is centered front to back, side to side. It is in equilibrium. / <--- rider \ <--- motorcycle The rider leans to the right while the bike leans to the left. The center of mass is in equilibrium again, keeping the rider and motorcycle from falling. \ <--- rider .\<--- motorcycle Charles, the following formula would explain it for the more technically minded, the important variables being xyz (unlike an aircraft, a bike has a limited y variable). rho is the density and g is the gravitational constant : cg * W = g * SSS x * rho(x,y,z) dx dy dz For an individual of about 1.8m tall moving from seated to standing results in an increase in y position of perhaps 30cm, while the transfer of mass from saddle to pegs is nearly double that. Hence the lowering of CoG. When I have time I'll get someone (maybe ask my prof to run a tut at varsity) to measure the change in position and mass and apply the formulas to give an indication of how much the change actually is so that this debate is based on fact instead of opinion. ''If you can dream it you can do it!''

Ha ha ha - Balderdash! :) The fact is that according to the CoG formula, the CoG is the weighted average of the mass of all the matter in the object concerned, relative to a fixed point in space. '''At no time does the manner in which parts of the object are attached enter the equation.''' This means that the CoG equation does not care whether your feet, hands or bum are touching the bike or not. All that matters is where your CoG is, relative to that of the bike. Try this little thought experiment. Imagine you need to cross the Niagara falls on a tightrope, on a bike that has its tyres removed so the rims fit onto the rope. You are given two choices: # Stand up on the pegs, or # Sit in a harness below the bike and the rope, that is attached via a rigid pole to the seat of the bike. In 1, the CoG is above the rope, and you will not learn that lesson ever again. In 2, the CoG is below the rope, and that is how circus acts do this trick. While I do not deny that it is easier to balance the bike while standing, the reason is not a lower CoG, it is because you can shift your CoG around more easily in order to affect the combined CoG.

Everybody come quick - the nerds are gonna BARNEY!!! :P j/k I'd be very interested to see what your prof says PeterO - my thought would also be that although your mass remains constant and your body moves up - you're connection to the bike is lowered, thus lowering your centre of gravity, the fact that you are a more "movable" weight just helps with stability and control. Picture this - if the footpegs were higher - say seat high, the difficulty in control with even the smallest movements of the feet would be exponentially increased due to a now higher centre of gravity. Same principle applies with cars - those, like the subaru, with horizontal low mount engines have better road holding due to (many factors including) a low centre of gravity, whilst a bakkie or similar with a higher mount engine (an Uno, although not officially a car, does apply here too) does not and roll on cornering is experienced to a far higher degree due to this (not rolling on the corner - but body roll) The idiot has spoken :P

Wow that's quite emotional! ... well I suppose that rather ends the discussion. As I said, I haven't applied the maths to a bike/rider combination and I am happpy to be proven wrong on my assumptions, so I shall certainly ask the prof to do the calcs for me and in fact explain the complete dynamics so we can understand the logic. I'll post the outcome. ''If you can dream it you can do it!''

mass creates gravity. Everyobject has it's own gravitational field. If you're sitting on the bike, you mass and the bikes mass are practically combined. when you stand you're parting the mass, and therefore the gravity. Assuming the bike is heavier than you are, the centre of gravity will be centered around the bike. So, you're technically not lowering the centre of gravity, but you are above it. Which is the same difference.

Center of gravity has absolutely nothing to do with standing on the pegs or sitting on the seat. It's all about the location of the mass in space. A better term is "center of mass". Sitting lowers the center of mass, standing raises it. It's that simple. Standing raises the center of mass. Sitting lowers the center of mass. Raising your the center of mass is a bad thing for a single rigid body. Think top heavy 4x4. They flip easier than a sports car. But a motorcycle with rider can be simulated as two rigid bodies hinged together. They will be illustrated as a line. | <--- rider | <--- motorcycle The rider is directly above motorcycle. The center of mass is centered front to back, side to side. It is in equilibrium. / <--- rider \ <--- motorcycle The rider leans to the right while the bike leans to the left. The center of mass is in equilibrium again, keeping the rider and motorcycle from falling. \ <--- rider .\<--- motorcycle The rider leans to the left and the bike leans to the left. The center of mass is no longer in equilibrium, it is to the left of the motorcycle inducing a fall. While standing raises your center of mass, it allows you to shift more weight from side to side, front to back, thus allowing the bike to move more side to side, front to back, keeping the center of mass in equilibrium, enabling you and the bike to stay upright and keep from falling. Ref: http://www.thumpertalk.com Corné Kloppers http://www.bikepics.com/members/pantsula/07f650gs/ 0849130391 ckloppers@gmail.com

Does this qaulify as standing up ?? . I RIDE THEREFORE I AM!

I see his feet are not on the pegs but near the handlebars. I suppose his center of gravity will therefore be very high. Judging by the picture about 15 meters. ;)

Corne is right guys. I know - because Peter's prof was probably tutored by me when I was younger. I kid you not - my degree is honours ''cum laude'' from Wits in (wait for it) '''Theoretical Physics and Applied Mathematics'''. (That's right, I did in one year two honours degrees, and won the Gold Medal in the mathematical sciences). So, on what basis would you elect to not believe me when I say that standing up raises the overall CoG? Another thought experiment. Some of you seem to believe that the CoG depends on where you attach the objects to each other. Okay - if that is true, then I put it to you that the CoG of the bike and rider is actually on the ground, and the bike can thus never fall over! This is because the bike is attached to the ground on the bottom of its wheels. QED.

okay okay... you win Prof Smarty pants. Sheesh. Feel better now?

Corne hasn't contributed to this thread. Are you drinking his wine again? I agree that when standing the 'overall' CoG goes up. But since you're not actually part of the bike, the CoG will be below you when standing. Maybe thats why everybody says its lowering the CoG. You're lowering it in relation to yourself.

Corne is right in that standing up on a cruiser is not advised... :)

The focus of the discussion should not be on COG. We agree now standing will raise COG? By standing up, -the bike can move more freely and steering with body weight happens effectively -The force on vertical line through your body's COG can be moved (obviously with body!),more in line with the outer footpeg, which will add to down force on line of wheel surface contact. Simply put, Traction = Force x K coeff, thus, increased downforce will result in increase in traction! regards

This whole CoG is frustrating. You should have read the discussions on the WD forum about it. I do suggest, however, that someone knowledgeable speak to the BMW instructors at countrytrax. I'm pretty certain they say CoG is lowered by standing, and considering many new riders learn from them, they can clear up any confusion before it starts.

Loving the humour here ...... Surely its not only about the COG but the dynamics and where the forces are applied to the bike. Imagine you had very short legs (or a preferance to ride in the bosk$k position) and your foot pegs were just below the seat, COG does not change but, the force and where they are applied alter hugely as to a position lower on the bike. What say ye my learned friends to steal someone elses phrase "you dont suppose im depriving a villge somewhere of an idiot do you "

This subject was discussed elsewhere on the forum some time ago, but, if you have ever ridden trials (foot up) you will understand that from the standing position it is far easier to transfer you weight to the selected foot peg and/or handlebar side and moving your body forward, backward, left or right to obtain balance and traction whilst not falling off. Try doing all that whilst sitting on/in the saddle. As for C o G who cares it's cool to stand and comfortable. This is my contribution all 2c worth. Ignore opinions, heed facts. Feet on the pegs, always.

Gotta agree with you Cheesy. Science is not my strong suite - so I don't really care about where gravity is going. The bike is easier to handle when standing, esp on slow technical stuff. and it really does feel great to stand while riding.

Tulips if you are enjoying the humour you obviously don't understand the gravity of the situation! The central topic is a weighty one, not to be taken lightly and certainly not to be taken lying down. Standing is the answer. I spoke to Neil about this thread. He's a karpenter and therefore technically minded and was able to explain the philosophy quite adequately ie if you don't stand up you fall down. Simple. Thanks Neil. ''If you can dream it you can do it!''

Andy says nothing. He just smiles.... Whatever floats your boat baby. I ride better and feel more in control off-road when standing up. I have 70 000 kilos of injury free riding and NO insurance claims or damage repairs which goes to support this!! As for tar... I get my fix from riding. I stand because I stand, I don't justify it or explain it. I just do. Andyman Yup that's me. Standing up in the traffic on the 1150GSA.

Well, I cannot compete with any formal qualification, nor do I have a prof hidden away somewhere, but I have a quality that has come in handy in the past: Logic. Try balancing a broomstick upright on your hand, without allowing your hand to move to the sides. Well, it does not realy work. This tells me that something is balanced when the weight hangs over equally to all sides at the contact point (your hand). It should not matter how high the CoG is if you can achieve this equal weight distribution. Your ability to balance the broomstick is thus greatly enhanced by moving your hand and keeping the CoG right above your hand. Bikes on the other hand only fall sideways (OK, in most cases) and to be able to balance one, you must be able to keep the CoG perfectly above the contact point to the ground by moving the CoG to either side. How high or low the CoG is, should not matter that much (long broomstick vs short broomstick?). If you are sitting on the bike, you as the rider do not have much control over moving the CoG to either side and you are stuck with the limited results from steering inputs. When you stand, I think the CoG does go higher, but more importantly you are now able to move the CoG easier (by moving your body independantly to the bike) to the side as well to counter the uneven distribution of weight to the left and right of the contact point (bottom of the wheels) to the ground. Does this make sense?

Precisely. Website Administrator [http://honeybadger.net Honey Badger IT Services]

Someone better tell Leon from Country Trax then, as I have done 3 courses with him and each time we have been told to stand to lower our C of G, forget the maths, the weight is transferred down through your legs to the pegs....and I am sure this is what is important. My wife is doing the intro course this weekend so I'll print this thread and get Leons opinion ;-)

I’ve had some fun with a traffic cop here on the West Coast the other day. He pulled me over because I was standing. Being very hardegat, he actually ordered me not to stand up will riding. His primary argument was that nobody is tested for that kind of riding during the licence test. I just pointed out to him that there is no law in this country that is forbidding me to stand while riding and until parliament has passed such legislation he does not really has a foot to stand on. Now I’m actually irritating him by standing up each time I see him guarding a road. There is nothing in this world as dangerous (and as irritating) as people in powerful governmental positions that don’t understand their role and position in society. I always remind myself when I’m confronted with these kind of situations (and individuals) that “power corrupts; absolute power corrupts absolutely” – alias John Emerich Edward Dalberg Acton, first Baron Acton (1834–1902). The ride is the destination.

Interesting comments all . Pete O ,you got my vote there buddy . I can say that on my bike at least ,the CoG is definately lower when I stand , cuz my feet are lower than my butt and the CoG on the bike will be on the pegs and not on the seat. Also it would be pretty pointless to stand up, if that would increase the bike's CoG when hitting tricky road surfaces. Anyway that's my 2 cents worth of gut feel . ps I am also "guilty" of standing on tar esp all along Tableview beachfront , despite the glares from other bikers cuz as Cheesy says its cool and comfortable, so who cares what ppl think hehe ''"4 wheels move the body,'' ''2 wheels move the soul"''

Abel play nice with the traffis ociffer. Now Freak hauls out the big wooden spoon for a good stirring. Remember that gravity sucks. "Practice makes perfect", horse pookey !! Perfect practice makes perfect, COG is important but means nothing. Correct body position is what it is all about. Lets go above the limits and consider when things start happening on the edge of what your reactions and brain can percieve. By the time you have considered your C.O.G. you would already have seen your A.S.S. Rather consider how the bike is going to react and work with it. The variables are enormous one must adapt instantly, fluently and constantly. Become one with the bike, dont worry about getting out of shape, be calm and flow with it. . . . . I RIDE THEREFORE I AM!

Nice pics Freak. You are quite right. The CoG is pretty unimportant when you are riding seriously and there are so many principles of physics interacting with each other (momentum, energy, friction, gyroscopic effects, torque, levers, equilibrium and more). I see that Renette now also goes onto my list of pilots I will not go flying with :) Luckily, the laws of physics do not succumb to democratic principles P) :) Website Administrator [http://honeybadger.net Honey Badger IT Services]

Many laws are bent by the female species.:-):-)

As are many credit cards ;)

Neil i know you meant to be funny. that's why you put 2 smiley faces so that even I as a mere woman could see that it was a joke :) :)but seriously i just want to be one of the boyz when i ride my bike and on this site so please dont tease me about being a woman , otherwise i might just have to join a knitting site, and then who will enlighten me about gyroscopics and torque and other wonderful things that could help me ride better( thanks Charles!) ''"4 wheels move the body,'' ''2 wheels move the soul"''

Watch out guys Renette already scolded me for being to slow on the way to work this morning. I RIDE THEREFORE I AM!

Exactly! please tell them Marius they mustn't mess with me hehe, and oops realised too late it was you whom i passed on the way to work this morning, othewise i would have slowed down and also admired the daisies :) ''"4 wheels move the body,'' ''2 wheels move the soul"''

Jep, goeie, korrekte en logiese verduideliking! Ja, die CoG beweeg beslis op (boontoe) saam met jou wanneer jy opstaan (eenvoudige toegepasde wiskunde). Die voordeel met staan-ry is dat die twee massas (jy en die bike) baie meer '''onafhanklik''' kan beweeg. Die hele storie het baie meer met '''traagheid''' (eng. inertia) en hefbome (eng "leverage") te doen as met CoG. Totale swaartepunt (CoG) speel maar 'n klein rol in 'n baie groter spel. In statiese situasie is CoG dikwels belangriker, maar hier het ons 'n '''dinamiese''' situasie. Traagheid is die groot rolspeler. (traagheid is 'n funksie van ''massa'' en ''versnelling'' van 'n voorwerp)

Ok enough with the maths here's the proof http://www.youtube.com/watch?v=xBw0yH509lw If you do the homework you sit, stand any where you bloody well like- amazing stuff Tulips I think this has been posted before but its worth the watch

If you do join a knitting site you'll probably bump in to Neil there. He just wants to be one of the girls. But he is really good at it, he can knit while standing and the CoG doesn't bother him at all. ;)

On the 8th of October at 06h39 no-one noticed that Charles said "bum". I would have preferred it if he had said buttocks, or glutis maximus - this is because I didn't understand anything else. Also Cloud, you are incorrect, Corne' did contribute at 09h40 on the 8th, therefore the supposition is that the imbibing of alcoholic beverages is a myth! TGIF Buddy Out there where we all belong.

ROFLMAO! :) :) :) Well spotted - I almost got away with it too ;-) Website Administrator [http://honeybadger.net Honey Badger IT Services]

Butt not one clear explaination of why when yourCOG is in the correct position/area,you still fall. This implies COG is a red herring!!!

So if my centre of gravity is dependent on the point of attachment of the two masses, then it follows that if I install a roof-rack on my bakkie, but attach the roof-rack to the chassis, then the bakkie will corner better with a load on the roof-rack than it will with a load in the loadbed, because the loadbed is higher than the chassis....? Just stirring :) Frank