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Zitat von Sanemancured im Beitrag #27Zitat von Mr. 36654 im Beitrag #17Zitat von sunshine247 im Beitrag #14 You're leaning your shoulders outboard of the MC's centerline while curling your hip and knee under the leaning bike to press the rear brake. In effect, you're trying to wrap yourself around a leaning bike.
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Zitat von Sanemancured im Beitrag #29Zitat von Mr. 36654 im Beitrag #23Zitat von Paul911 im Beitrag #22Zitat von Mr. 36654 im Beitrag #21 Gyroscopic precession (or is procession) is one of many possible factors (degrees of freedom) one can include when modeling vehicle dynamics. The important question is .......... is it a dominant factor. A friend of mine, is an Autopilot designer (programmer) and, at last I knew, a KTM rider. We were in some meeting and listening to some less experienced autopilot designer/programmer ramble on about solving all the coefficients for a 10 x 10 stability matrix. My friend leans over after this has gone on for far too long and says.........."Everyone knows it's a 10x10 matrix. What everyone doesn't know is only 2 of those terms (out of 100) are really important to control the vehicle". I'm sure my friend exaggerated on the low side, relative to the number of important (dominant) terms, but his point was well made. Lots of things/forces can have an effect on vehicle dynamics, but only a few are really significant.
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Zitat von Mr. 36654 im Beitrag #30Zitat von Sanemancured im Beitrag #27Zitat von Mr. 36654 im Beitrag #17Zitat von sunshine247 im Beitrag #14 By counterbalancing do you mean dropping the bike further to the right while straightening your right arm and bending your left to allow the upper body to compensate? I tend not to counterbalance, at least nothing extreme. It's a good technique but it isn't taught at our advanced level. I guess you guys do it more to the left for U turns? If I start on full lock, keep it there and counterbalance slightly the bike turns on a sixpence.... |
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Zitat von Mr. 36654 im Beitrag #32Zitat von Sanemancured im Beitrag #29Zitat von Mr. 36654 im Beitrag #23Zitat von Paul911 im Beitrag #22Zitat von Mr. 36654 im Beitrag #21 Being a retired engineer (not to be confused with a mechanic or technician, although I have been all three) I can tend to want to understand such things in depth. From what I have researched, read and evaluated the two major factors at speeds above walking pace are gyroscopic precession and forces acting through the centre of mass against a change of direction. The latter being significantly greater. A chap in a senior advanced training role locally likes to portray himself as Mr Right or Mr 'cleverer than you are'. I've seen him ride and he constantly 'showboats' with his positioning saying in effect 'look at me!'. At an evening meeting about a totally unconnected subject he took the opportunity as an 'engineer' (without an engineering degree) to take the stage and lecture us all on how GP was everything and the one and only countersteering mechanism. Not that he annoys me or gets under my skin you understand  |
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Zitat von Sanemancured im Beitrag #34Zitat von Mr. 36654 im Beitrag #32Zitat von Sanemancured im Beitrag #29Zitat von Mr. 36654 im Beitrag #23Zitat von Paul911 im Beitrag #22Zitat von Mr. 36654 im Beitrag #21 Ever read V. Cossalter's "Motorcycle Dynamics"? It's insightful, but some of the recent work on GP makes a few of his conclusions a bit outdated. Like you, I'm interested in understanding the subject but I come from a background where you start a development project with 1st and 2nd order design/analysis tools to "find the piece of paper". At that point, you move to higher-order tools to refine the design. Sadly, with the advent of cheap computers and infinite computational capacity, today's world is focused on creating models of a universe of options which often overwhelms the engineer/analyst when they attempt to determine the critical inputs/features which govern performance. In the motorcycle training world, this phenomenon appears occasionally when some training provider announces that Racer B has been doing X and he went faster/stopped quicker/turned tighter. I've actually witnessed a training class were the instructor told the students to lay on the tank when approaching a point of maximum braking and then push up on the bars to reduce load transfer to the front wheel. Told to do this and told it was effective, most all the students reported it shortened their stops. Sadly, Newton's 3rd law, says the push-up was only adding to the load transfer to the front wheel. So, if you are ever in the US, I'll buy you a beer
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#36 | RE: I dropped the RS yesterday
Tue May 17, 2022 8:37 pm (Last edited: Tue May 17, 2022 8:38 pm)
Tue May 17, 2022 8:37 pm (Last edited: Tue May 17, 2022 8:38 pm)
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I think IF your feet don't get down quick enough then gravity can always overpower you! |
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Zitat von Dave H im Beitrag #36 And, I prefer a shoe with good traction. Gravel parking lots and gravel roads are pretty common in my area.
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Zitat von Dave H im Beitrag #36 In this case, with a few mph and some lean angle, no foot down was ever going to save me. Marc Marquez would have struggled. |
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Zitat von Mr. 36654 im Beitrag #23Zitat von Paul911 im Beitrag #22Zitat von Mr. 36654 im Beitrag #21 I expect the gyroscopic forces of a motorbike will be different as it has an engine spinning at several thousand RPM. Was actually watching some interesting videos on youtube about it recently, and the main balancing effect on a push-bike seemed to be micro steering movements, with the gyro effect being next to nothing as you say. It's an interesting topic. I've often wondered how the boxer engine compares to say an in-line 4. But in either cases the main plane of rotation is vertical. On my second test ride of an RS I was being very conscious of it, and upping the revs at low speed, not relying on the torque, and it was noticeable. |
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Zitat von Becksy im Beitrag #39Zitat von Mr. 36654 im Beitrag #23Zitat von Paul911 im Beitrag #22Zitat von Mr. 36654 im Beitrag #21 According to Vittore Cossalter's "Motorcycle Dynamics", pages 287 thru 298, the impact of a transverse engine in a turn will be ~10% of the gyroscopic forces of the wheels. In the case of an inline shaft (Boxer or Guzzi), the engine gyroscopic force in a turn yields a minor pitch angle to the suspension. In both cases, the engine RPM and turn radius and speed are assumed constant. When you add engine RPM variations, you'll have torque loads along the engine shaft line.
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Zitat von Sanemancured im Beitrag #34 An arrogant self opinionated idiot at an advanced motorcycling club - I  refuse to believe it
Double Lupin owner PCP free
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Having read all the above, I will venture that in my experience when a Boxer engine decides to stall, it locks up very quickly. And you’re nearly alway going horizontal. |
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Zitat von tony.parker im Beitrag #15 I disagree.
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#45 | RE: I dropped the RS yesterday
Sat Jun 04, 2022 1:13 pm (Last edited: Sat Jun 04, 2022 1:16 pm)
Sat Jun 04, 2022 1:13 pm (Last edited: Sat Jun 04, 2022 1:16 pm)
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The weight of the flywheel, regardless of cylinder count, goes a long way towards masking any operator error at the controls. |
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