Karen_Agusta Posted May 30, 2010 Share Posted May 30, 2010 Fellow Riders . I wrote several articles in the general section I was told those articles are better posted here Rather than crosspost them which is a big time no-no I am just going to post the links to articles I wrote You can go ahead and peek at them there if you wish to . . . . Rubber Side Down . Karen Link to comment Share on other sites More sharing options...
Karen_Agusta Posted May 31, 2010 Author Share Posted May 31, 2010 Just a follow up to include ... that is all ... this is my introcution I wrote to this board ... since most of you have read it you do not have to read at it all ... I am merely including this as part of the compilation of technical articles I have written thus far to keep them in one place ... . ----------------------------------------------------------------------------------------------------- . Because I know "just a little" about motorcycles and the fact that An engine is essentially an air pump of a combustible mixture Regarding air - it is not "sucked" or "pulled" into the engine There are no little hands reaching out grabing air molecules Air may only be pushed into an engine it is never pulled into one The air pressure at sea level is 14.7 pounds per square inch On the intake stroke carb and intake valve in the open position The piston is travelling downward creating a void inside the engine Thus there is an "empty space" being made inside the engines cylinder The 14.7 PSI pressure on the opposite site of the carb and valve PUSHES AIR into the empty space created by the downward travelling piston Thus in order to increase the amout of air a given engine can pump Its design must maximize airflow this is known as volumetric efficiency Or the air pressure into the engine be increased via super or turbo charging The same is true for a vacuum cleaner or any other such device air is pushed in Another board asked me to write an article on purchasing your first bike For the discussion I used motorcycle racing as the primary topic That an understanding of the machine itself may thereby be obtained Thus making selection the device best suited to your purposes easier ... Karen . http://www.youtube.c...h?v=yTgyBmdD4f4 . http://www.youtube.c...h?v=7X08zELY-lo . http://www.youtube.c...h?v=6Mfwv_GwhFs . http://www.youtube.c...h?v=vURjSJi5Zjk . http://www.youtube.c...h?v=7x7lwPzayHI . . . Moto GP / F1 Racing Engines . Engine revolutions fourteen thousand rpm at starting line Rider slips clutch out torque / not well at low rpm Large drop in RPM as engine propels bike from start Once motorcycle returns to proper rpm range Must at all times be kept there by selecting correct gear Usually between eight and fourteen thousand rpms . http://www.youtube.c...h?v=-NHEAxKGw8Y . http://www.youtube.c...h?v=btnOW31bg14 . . . As motorcycle begins to move it is held upright This occurs at very low revolutions through gyroscopic precession Imagine a bottle tied to a string you hold in your hand The bottle and the end of the string is one inch above the ground You begin to spin in a circle and as you do so the bottle rises Once you are spinning fast you feel the tension rise upon the string That is because the atoms in the bottle are being "thrown" away from you The only reason the bottle remains is the strength of the string Exceeds the tension the bottle applies to it however Should you let go of the string or the string should break The bottle will fly away ... this is what occurs in a motorcycle wheel The only difference is that it occurs in a vertically instead of horizontally Here as in discuss you have made yourself the axis about this the item processes . http://www.youtube.c...h?v=sEW1ZsSCVHE . http://www.youtube.c...h?v=IEwAry0GARw . http://www.youtube.c...h?v=8H98BgRzpOM . http://www.youtube.c...h?v=pF_SUvPAOSs . To test this to the following ... Get an old bicycle wheel Put a bar through where the axle was Use some duct tape on the bar to keep it centered Have a friend spin the wheel fast as you hold it Now try to turn the wheel to the left ... it does not The wheels force shall alter direction and flip over Here she is trying to turn the wheel to the left of right When she does you shall see what occurs. This is gyroscopic motion / inertia What is important to realize here other than what you see Is that these people are not "flipping the wheel over" They are with their hands attempting to turn it to the left or right The flipping to the side you see is the gyroscopes resistance to that Thus is is important to remember a motorcycle is not a car It is a system based upon two spinning gyroscopes Therefore it reacts as one and must be driven that way . http://www.youtube.c...h?v=TSC6e2e5lQw . http://www.youtube.c...h?v=_VAavF8EJzw . http://www.youtube.c...h?v=eLRFsy0fOTE . http://www.youtube.c...h?v=YzgUiremOtw . . . Directed forward rider pushes bars away from direction of turn Wheels act as gyroscopes countersteering leans bike into turn First Law of Motion: Body in motion persists in a straight line unless compelled to change This is one of the hardest for new riders Also many riders are not taught this And even experienced riders may argue this However the fact remains to steer a bike to the left You must push the handlebars to the right To steer a motorcycle to the right You must turn the bars to the left This is not only important to turn at high speed If you have a car coming at you from the right And you are travelling over ten miles per hour You must turn towards the object If you own a bicycle find a hill and ride down it Get the bike going fairly quick and very very gently Turn the bars to the left and you will turn to the right Or push on the left handgrip go left I am including this to such a great degree Because if you ride a bike you MUST understand this In racing we use this to "throw the bike over hard" This allows us to dive into a turn steeply I am including this with some degree of intensity There is also a myth that a motorcycle is turned by leaning I do not recommend you try this unless you are an experienced rider Even then you may dump your bike however as a demonstration I one time leaned far to the left knee down and By countersteering turned the bike to the right Thus leaning is a part of turning but there is more to it That is how the racer throws the bike into the turn so quickly Because if you ride a motorcycle it may save your life one day . http://www.youtube.c...h?v=oVa2Ax-Dins . http://www.youtube.c...h?v=M1A7o-aXvqU . http://www.youtube.c...h?v=s8M_7fBR63Y . http://www.youtube.c...h?v=v5AmFGioYDg . Ok so that is how the racer throws the bike down into the turn so quickly . . . Braking = Kinetic Energy and thermodynamics . ---------------------------------------------------------------------------------------- . From wikipedia . The kinetic energy of an object is the extra energy which it possesses due to its motion. It is defined as the work needed to accelerate a body of a given mass from rest to its current velocity. Having gained this energy during its acceleration, the body maintains this kinetic energy unless its speed changes. Negative work of the same magnitude would be required to return the body to a state of rest from that velocity. . Friction is not a fundamental force, as it is derived from electromagnetic force between charged particles, including electrons, protons, atoms, and molecules, and so cannot be calculated from first principles, but instead must be found empirically. When contacting surfaces move relative to each other, the friction between the two surfaces converts kinetic energy into thermal energy, or heat. . ---------------------------------------------------------------------------------------- . In other words energy was applied to accelerate the object Thus energy must be applied to slow the object In machinery we use frictional energy converting motion to heat The kinetic energy of an object is the extra energy Which it possesses due to its motion The kinetic energy of a single object Is completely frame-dependent (relative) For example, a bullet racing by a non-moving observer Has kinetic energy in the reference to frame of this observer But the same bullet has zero kinetic energy to itself Thus at steady speed the motorcycle applies zero kinetic energy to the rider For the rider is not part of the same travelling system as the motorcycle However this becomes a completely different situation Slowing motorcycle from 200to 40 mph via brakes frictional conversion of forward momentum / energy to heat using Through the use of advanced ceramic materials . http://www.youtube.c...h?v=D8MsuFHlc54 . http://www.youtube.c...h?v=m1dv_y_3EK0 . http://www.youtube.c...h?v=L8pnaRpDU1A . The idea in racing unlike in road riding is this On the road you want to brake in a slow and smooth motion Taking your time slowing the bike easily In racing you want to brake as late as you possibly can Hammer on the brakes and then get back on the throttle . However there are severe issues in motorcycle braking 1: if you are hard in a turn braking will want to throw the bike over 2: This is called highsiding where the bike flips you over itself 3: Not too many braking examples however it is common in racing . http://www.youtube.c...h?v=KREIjnk6jTI . http://www.youtube.c...h?v=kGdU6ypYXD4 . Yet another issue is the independent front and rear brakes Thus you must balance the force applied to both brakes perfectly On the front brake if you apply it wrong and use To much force and you shall go over the front wheel . http://www.youtube.c...h?v=ARdw0WrV_gE . Or you shall put the wheel into a skid throwing you down . However much more common is the rear wheel lock up Though I do not have vids of that if you have ever seen A motorcycle try to stop quickly and the rear wheel go everywhere You see the read wheel slide all over ... the rider must counteract that . http://www.youtube.c...h?v=BZqXPhK_3LE . http://www.youtube.c...h?v=kfmWx0tYRV8 . http://www.youtube.c...h?v=s0P3tYskn84 . http://www.youtube.c...h?v=HBm_L5Xt780 . Also we do not have windshield wipers Remember unlike on a car where you can stab the brakes On a motorbike even in a panic or in a race You must perfectly modulate the brakes or you will crash You can easily crash through improper braking alone Furthermore remember the ONLY thing keeping you upright I gyroscopic precession. Thus should you lock up a wheel Even at 60 MPG there is nothing keeping you upright at all Therefore as the racer brakes they must do so perfectly On both wheels in order to slow the bike correctly . . . Centrifugal Force: . As you turn certifugal force wants you to go to the outside of the turn lean angle of the motorbike counteract the force pushing you to the outside Here is where Chemistry comes into play for unlike the older days Today the advanced compounds in the tires allow lean angles to 60 Degrees-Very fine line between optimum cornering and crashing Outward and downward forward forces balanced precisely You must consider the camber of the curve to determine speed You must also know if it is a decreasing radius curve as well One other common issue is called going wide on the turn To lean a motorcycle hard over is frightening it feels like falling So due to this fear to do not throw the bike over hard enough By this choice you do not make the turn and you drift wide on the corner . http://www.youtube.c...h?v=Hx7RvfukIG4 . http://www.youtube.c...h?v=mTnKkdIfVXQ . http://www.youtube.c...h?v=cq9Ua5Tuw3Y . http://www.youtube.c...h?v=5wYD9SSBBNQ . http://www.youtube.c...h?v=sN3bD4U5yJ4 . http://www.youtube.c...h?v=W16hsnIur1Y . http://www.youtube.c...h?v=QCg3BMGe52M . http://www.youtube.c...h?v=3aW01UaHyC4 . http://www.youtube.c...h?v=7mHTzOskcQE . . . Thus a motorcycle excellent example how physics work A motorcycle at a constant speed defined as "v" for velocity in motion Is about to enter a level, circular, curve The curve is defined a r for the radius of the curve The radius r lean angle from the vertical position Is approximated by the following relationship First I shall need to explain theta ... . Theta ... Theta is used When determining the measure of the angle in the work equation, it is important to recognize that the angle has a precise definition - it is the angle between the force and the displacement vector. An explanation would be applying a force to displace a motorbike up a hill to the top of the hill. A force is applied to a bike to displace it up the hill at constant speed. Say 30 MPH. . Several incline angles are used progressively steeper thus you must increase the force to maintain 30 mph. However do not forget that the force is always applied parallel to the incline. And the displacement of the motorbike is also parallel to the incline as well. These are defined a F for force and D for displacement. Since F and d are in the same direction, the angle theta in the work equation is 0 degrees. For they are in a relationship of zero degrees to one another. Nevertheless you may wish to experienced the strong temptation to measure the angle of incline and use it in the equation. Do not do so because angle. It is defined as the angle between the force and the displacement vector. . Next issue is the definition of Tangent . Tangent is as follows ... a straight line or plane that touches a curve or curved surface at a point but does not intersect it at that point ratio of the opposite to the adjacent side of a right-angled triangle ... Tangent line to a curve at a given point is the straight line that "just touches" the curve at that point ... Tangent plane to a curve is the plane that contains all the lines tangent to a specific point on a surface . The equation for it is as follows . tan (\theta) = \frac {v^2} {rg} where g is the acceleration due to gravity . What this means is as follows ... the speed of the bike and the weight of the bike, the radius, displacement, and camber of the turn shall determine the amount you lean and balance the bike to thereby counteracting the centrifugul force trying to make you go wide on the turn allowing you (provided you do not exceed the frictional capability of the tires in doing so) to steer to the apex of the turn properly and set the bike for the next turn. . Thus when people ask me what should my first bike be. Sure the common answers would be . The Ninja 250r . http://www.kawasaki.....ns.aspx?id=431 . The Suzuki Tu250 . http://www.suzukicyc....egory=standard . The yamaha V Star250 (AN EXCELLENT BEGINNERS RIDE OF HIGH QUALITY AND BEAUTIFUL FINISH) . http://www.starmotor....89/0/home.aspx . The Honda 250 rebel . http://powersports.h...2009/rebel.aspx . However here shows how to ride your motorcycle as this person is doing ... taking an extremely common and well made street bike (the Ninja 250r which I plan to purchase and am already set up with the dealer to do) onto the track and showing what a little 250cc street bike can do when ridden by skilled riders ... on the track ... not on the street ... . http://www.youtube.c...h?v=y2HnEld-z3Q . ----------------------------------------------------------------------------------------------------- . Rubber Side Down . Karen . Link to comment Share on other sites More sharing options...
blackhat250 Posted June 1, 2010 Share Posted June 1, 2010 Karen" you are far too inteligent for the bikers on here, Are you a genius , whats your day job,??? Link to comment Share on other sites More sharing options...
Karen_Agusta Posted June 12, 2010 Author Share Posted June 12, 2010 Thank you sweetie . There is not better or more appreciated compliement than anyone could give to me than ... "genius" you really know how to touch a girls heart. . After fifteen years in motorcycles (which before I got into I took one year of college for mechanical engineering) ... I decided to go back to college and get an AA degree in computer programming / repair ... my day job is network administrator for a health care facility. Though they are shutting down and relocating which I decided not to do ... so now I am just a Biker Chick. . Karen Karen" you are far too inteligent for the bikers on here, Are you a genius , whats your day job,??? Link to comment Share on other sites More sharing options...
barkwindjammer Posted June 12, 2010 Share Posted June 12, 2010 Clicky clicky Link to comment Share on other sites More sharing options...
Karen_Agusta Posted June 13, 2010 Author Share Posted June 13, 2010 Like the new flag picture ... and also the Clicky Cliky ... though are you implying I am fast forward or fast behind Clicky clicky Link to comment Share on other sites More sharing options...
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