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hobot

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Everything posted by hobot

  1. I salute Kieth Code's bravery to allow me to break barriers into center of gravity pivoting turns, prior to apex let offs It takes thrust and traction to turn hard, brakes are for saves not going in harder. The only time to use rear in a turn is if the trail braking save is too late or hits Gravel and bike suddenly lowsides, STAB the rear like you were SOMPING your foot down to hold bike up like a flat tracker, then get off it so enuff resultant hi side instantly resets ya back to level to get second chance at some serious undivded one vector stopping straight up and inline like a stoppie stunter. One other rare occassion of rear brake helping the front in panic stops is to LOCK both at once and spin bike totally sideways to motion and stay on em using both side walls to resist tarmac or pile up loose stuff off track. LIfe and death barrier riskers may develop this instantly but some practice on bicyce or atleast forethoght helps to realize bikes can twist on Center of Gravity, besides just at front or just at rear... so>>> Axioms to phantom phantastic phases To turn one must cause a force to act towards the center of the turn, its radius line, like a rock swung around your head. Books call this an acceleration vector, as its got two componets, its direction and its force. Tires and torque supply the force and best force occurs about 10% tire grind. Less than this is not even in this disscusstion, more than this is what scares or upsets us. Cycles go thru series of steering phases, depending on the angle of the rear and the resistence of wheel and crank sfaft gryo forces. Up to human jogging speeds, straight steering of front aims the rear to bring rest of bike along. Gryo force becomes significant at human runing speeds. Turning or leaning a gryo 90' to its rotation makes it develope opposite forces to resist this change very fast. So we lean into turn radius to overcome this. This is easy to do up to horse race speeds, by mere leans of body, but only If fork is not trapped by a damper so free to just dolly wheel, it just naturally begins to self countersteer. Once into fast bird flight speeds, gryo force gets too strong to overcome very fast by mere butt shifts so we start relying on assisted counter steering of front tire off center line to allow bike mass falling over to assist aginst gryo's resistence to changes of angle. Yet this gryo resistence to change of angle gives a cycle another dimension of handling over 3 or 4 or more wheeled conveyences. All the above is just to help get REAR's thrust aimed towards tangent of the turn radius. If powered over 10% grind along its axis it begins to divide its traction potential in two directions at once, which don't add back up to a one way only use of traciton buget, so rear can slide, until you let off spin out power, which means slowing down the fun or it can get sideways to line of travel till traction stops being divided and it hooks back up and on over in worse cases. [below only valid on essentially LEVEL surfaces please] Further conflict arises d/t counter steering is aiming front away from center of turn and tending to drop front as rear powering out tends to rise rear, up to point the frame twists and springs. A skilled pilot can fight this conflict, easeing in more and more countersteer lean aginst more and more rear thrust until gryo force simplely tips bike over thru its midline CoG, so may lever off both tires evenly. Generally bike occilations over tax one end or the other 1st but loosing rear out from under is way more forgiveable than front slip outs. To cut to the chiances, funnest way in and around is to load the front the least possible, one way is get into best accelerating gear and about where the early birds are 1st braking, [or rear braking to get sense of balance for this] nail it for best acceleration >>> right up to point of apex flick over, so as lean lowers tire grip, speed and power is already enough your butt pressure can swing out rear as if it was on Gravel, but just add more power if lazy, or more countersteer tip out, if power alone wasn't enough to get the rear loose so you can swing it at will YET also loose enough still able to resist/control its swing too. In this fun way to pre-pare a slide for max turn G's, you must spin the bike on its vertical CoG before you get to apex, so only a short fast skip of loss of thrust the whole way around, go in so hard the rear is lowsiding the bike. To save this low side, must re-transition to straight steer. This both resists rear's lowside by the hi side force and will aim front back into radius for final leap out of apex, just as decreasing a radii as you can stand the burn out dounut at hi G's. Not a long lazy flat track affair. Traction must be treated/creasted as a digital on/off level to pull this off, slide too far or not enough no fun, but slide you will if you are seeking limits, till it feels same as a a flat tire, hi wind gusts or Gravel path antics. hobot
  2. Boy oh boy pilot GWalker did you ever ask a loaded question. I think you got your best answer above about the use of C/s to get it leaning and thereby turning and just leave it where it feels easy to hold as long as you like your speed, traction and line. BUT depending on that big bad black thing's traction state, the bank/grade of the track and for sure the wind you may have to diddle the front to the next steady state of ease. What is so neat/fascinationg/disconerting/gleeful to me is that bikes go thru transitions of handling/steering. First handling state is "straight steering" when the rear tire is mostly vertical, 7-9 mph in parking lot example [or in fast transitions at almost the ton durring the phase rear is passing thru near vertical in violent direction changes] Next phase is when rear steering begins to rule by its leaning action, about 10 mph to over sound barrier, as long as rear stays planted and is not spining much nor skipping out much... the front tire must then swivel to match the rear's commands, as when body steering hands off OR the bars can be brought into play, to help the rear rule the roost, by inducing more lean, called [a misnomer to me] "countersteering". Speeds above 65-75 hinder body steering alone, as wheel gryo forces become significant enough to resist the free swing of the forks, to match em to the rear's lean. Same thing with trying to body steer with ANY steering damper involved/interferring, as terrors or physics will stop that foolishness. Gryo forces do not effect handling or line in any detectable maner but does increase the force needed to change front wheel aiming and the ease to flick the bike as speed increases. It just makes you work harder. That's about all there is to it if you stay below 110% tire use. But if you seek the looseness Master Code speaks of riding vintage tires but on new compounds OR find your self on slick stuff OR put enough power down the front is light or even lifting OR in states the bike is saved from a lowside by a jerk up into highside posture, THEN you will pass thru phases of C/s vs S/s and back again. Its similar to turning into the direction of a slide on a car. Durring this flit thru the C/s v S/s transition [which really means leaned vs vertical rear tire states] there is an instant where you should actually be leting bars go so the forks can jib over on their own in a timely just the right amount, way faster than a pilot can perform reliablely. You do have to kinda catch it though or over in a highside ya go. Futher featutes to explore once into the speed and loads range tires feel greasey: A goodly spining rear tire will weather vane by gravity downhill. An off slope track especially wet/sandy, rear may want to walk off beside you towards hellward side. If you got room and want to keep the acceleration going you just S/s abit or ALOT! so rear stays more vertical and its thrust still aims at your line even as bike drifts and looks cockeye'd. Looking down on a rider as his rear hydroplanes out as he leans to turn, he can back off or he can S/s towards the rear's slide and ride on it grining big time. Centrifugal tangent force can be used to get a spining rear pointed where you want it too but must be planned for and broken loose abit before the apex by great help of bar C/s to lean it over far and then great gobs of guick S/s as you hit apex and let rear hook up for the leap out. Sorta flat tracker style but way sharper jerky'r guicker over with gone. Rear suspension must be full loaded going into this so you can control the angle of rear the instant it regrips. If theres a new turn right then let it highide right on over and Volia next instant bike has transitioned again so that 1st S/s becomes C/s and you didn't even move the bars. Wonderfully weird. Increasing throttle in turns likes more C/s input to hold a radius trailing throttle in turns prefers less C/s to hold a line. Turning going up hill, more throttle raises bike and requires more C/s, when rounding a down hiller, more power lowers bike therefore less C/s for same radius as the uphill example. Wind blowing from inside corner lifts and raises bike lean so more C/s to compensate right up to the point the bike will lift off and skip sideways a foot or more which can be caught if you just hold the same steady state C/s/lean you had on lift off and let the forks occillate on touch down while you try to hold her steady and not try to actively compensate otherwise, just act like a damper. Not for racing but if caught out in storm front in Mt's wind may win no matter what. Funest deal is to make every corner act like a decreasing radius off canter turn, harder and harder lean, C/s and power till quick S/s to save it and flick the next way. Yummy to the tummy. As to dampers, my own personal opinion now is the less the better and to me mainly implies a bad set up or poor bike design. I find gusty winds the most valuable use for them and on rough roads that jerk the bars entering or in exiting turns. Also there is a whole world of difference between a damper that has a limited radius of action and the ones that restricts the whole fork range. The faster you want to change direction or make corrections the less desireable a damper becomes up to the point of flat limiting bike and rider performance and preventing otherwise possible saves. damhik. Safe fast playing y'all. hobot
  3. Hey ho yo'all, I've been bitten so bad by the cornering bug I can't hardly sleep. I am in awe and fascination of CSBCS's various topics and practioners. I'm a newbie to racer lingo and have some dropouts of details on following all the info so bare with me on my stumbles on what I'd like to state and publically ponder on. My short time on limited # of M/c's though has been very rich in rather extreme conditions with hard fast lessions I'll share and proablely provoke with, though not out of disrepect but because this stuff IS a deadly serious but TOTALLY gleeful addiction to me and I find similar insights being touched on or ridden well on here. The door was open, I'm a sick sick puppy and seek to cure or spread my illness So many factors so many corners... Its winter so please shoot me down in flames if ya can get close enough to throw a ember in me spokes. My basic tenets: matter does not occupy same spaces at once. energy is not lost just transformed, everything is meant to flow from fuel to ideas. full traction is make or break digital not smooth at max use of it. all bikes have bounce back karma, good or bad, learn it, at slow speed. rear steer/lean rules when it really matters belive it or bad juju. front merely keeps nose off dirt when not using rear fully. extra traction snatches are ontap even when tires are squealing and grinding but only in thin slivers of time to apply and let recover. almost crashing from a lowside to a highside is the fastest way way to turn if you can enter turn so hot under power the front won't hold before the apex. nothing turns sharper than a skiping outrear, EXCEPT a skipping out front which is me big #1 Taboo. Period! funnest turns are not so smooth as digital overcomings of tire grip between transitions of balanced states, kind of a cheating to get traction losses over and done with quickly to get back to the launch program by cutting the corners into sharp straight aways. when able to make and break rear out at will run the of mill corners feel like canyon wall riding delights as lean and G's apporach that. m/c's go thru steer to countsteer tranistions and back with lean, speed, power, grade and bank changes. airplane like, as each input does more than one thing at once, non linearly too yahoo! If ya got to break best get it over with first not later or dog gone it ya's back into depending on that meek front limiter. Oh btw, fastest way to stop, gulp, if need be, is fully locked up tires sideways at belly scraping angle. Done right like a skier on edges ya'll just pop right up stopped, with many great poundings in the chest too. Best sensation is disapearing striaght thru coccyx into a skipping rear patch. Lean angles, if at loads less than making hot tarmac as loose as a pebbled surface then I have nothing to add just carry on as you are, but at apporaches and follow though rates that begin or overwhelm front traction, either by power input making the front light/lift, so the rear skips on around or by pure glorious leaning over, then that big ol' knee bone just flat gets in the space. Spining crossed up is one way with less lean but wastes time, tire and traction yet is a fall back reserve if goofing up or hazard changes the plans. Ever see a riderless bike self correct with jerks and twitches as it runs on down the track? Ever see a thrown rider recover and ride out an impossiblely jerking twitching steed? Yes,Yikes,similar. Gryo force increases bar's resistence to change front tire direction but it don't effect handling otherwise. Jumping 4 lane hwy at about 60 wiggling the spining front and waving at gap jawed cagers or steering hands off turns by lean just fine only to 70's convined me of this non issue. Front must be free, so not to resist but to assist the the rears lean, That is key to allow low to highside crash steering antics. OH, don't never gun a hot rod bike nor tap its rear brake while in flight or yo'll get a test of instant inertia and attitude adjustment. I bow to the scope and scale and outrageous explorations of your Master Code. My one brief exposure has allowed me to finish up my own flight envelope exceedings. BUT how do you sleep when the vivid dreams are replaying fast zoom in videos straight into rock faces at apexes right up to the edge hitting full torque band throwing it down on both sidewalls till scaping and nailing it harder to break free and just jet ski its tail into an erie steady state into the clam eye of a hurrance just before the next storm wall hits... again and againandagain... hobot
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