Author Topic: Vulfy's video thread  (Read 28827 times)

Vulfy

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Re: Vulfy's video thread
« Reply #15 on: May 30, 2012, 10:38:09 PM »
Well, thank you all for great input so far.
I hope this is helping others to evaluate their strong and weak points, as well as provide good info on proper technique. 

Here is the latest clip of my practice session:

05.30.12 Enldess 8's


I'm very happy with what I was able to achieve today.   Motogymkhanaman's  input and coin example is priceless, and helped a great deal.  I'm slowly starting to feel that I'm bringing my front wheel around rear.   Getting rear wheel into a tight spiral and letting it "lead" bike's entire motion.  Basically rear wheel is dictating how bike behaves, how much it leans, and how much and how fast bars turn into a full lock. 

One thing I've noticed, is that hanging off the bike on the inside of a turn helps a great deal.   Getting torso low on the tank makes it less scary to lean the bike even more into the turn. 
I stopped counter-balancing in the tight turns, and it feels more natural.   

At this point I feel I need more practice to get more comfortable with motions, lean angle, flicking faster into the turn, and slowly start bringing up speed and harder brakes. 

P.S.  I opted out for half cut tennis balls for today's practice, a they take a lot less space in the backpack, and are a lot less conspicuous.

BillZ

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Re: Vulfy's video thread
« Reply #16 on: May 31, 2012, 08:58:53 AM »
Another thing that I have been experimenting with involves another aspect of body position.  I have been reading another forum about riding technique; interesting side point to this conversation  is that this forum, AMGRASS, and the KYTwisted forum at are the only two places that I have found actual advice regarding riding technique.  There are lots of forums that post technical advice, as well as advice and opinions about oil, tires, mechanical, etc., but finding actual riding advice is extremely rare.

From the KYTwisted forum, I have discovered that if you turn your body, using your torso and hips, into the turn, the bike will follow, almost like power steering.  I have been experimenting with this technique to avoid a common error called riding "twisted" wherein the rider will slide off the seat, with the intention of leaning into a turn, but keep the torso over the handle bars, thus twisting his/her body over the bike to maintain a centered body position.  Consequently, the rider's body is twisted over the bike and fails to actually gain the maximum benefit of leaning into a turn.

Now, Iím not talking about hanging off your bike like some of the speed racers you may see at track day.  We cone freaks donít need that much lean angle to affect a clean turn.  What I was doing was very subtle and very effective.  Using small amounts of lean angle, adding small amounts of correction through the turn, creates a smooth as well as relaxed turn.

This effect has been further described as "kiss your mirror" by simply turning your body into the turn, from the hips and torso, while moving your head toward the mirror, i.e. "kissing the mirror."  My testing of this technique has allowed me to relax my grip on the handle bars and use much more of my body to control the turn of the bike, almost to the point of feeling like "power steering."  It has amazed me that I can shift my weight slightly from the hips and torso toward the inside of the turn, leaning very slightly, as appropriate for the radius of the turn, remain almost silent in my arms and hands, and the bike will follow through a clean line passing the apex of the turn, and straighten up as I accelerate out of the turn.  I keep both hands on both bars and remain alert and in control, but relaxed, while controlling the throttle and speed.

I am fortunate to live in an area that requires me to ride 25 miles to work, through a random selection of nice turns, some sweeping and some shorter radius, with extremely low traffic volume, to allow me to test this technique with very low risk or speed without impeding traffic.  The results are simply amazing.

I was using this technique during my last GP8 practice session, with limited success, because I didn't understand exactly what I was doing, while doing it, and didn't have enough time left in my session to fully analyze the input and results.  Now, I understand what I was doing and will complete the analysis during my next session, hopefully this weekend.
Lean into it...

Vulfy

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Re: Vulfy's video thread
« Reply #17 on: June 02, 2012, 08:00:54 PM »
yup yup, fully agree.  I like the "torso to the mirror"  as for me  "kissing the mirror" might still leave the body contorted on the bike, while just putting my head to the mirror.

My latest practice clip,  just one run out of many, but this was the fastest one  40-41 seconds.  Wet pavement didn't help, but even if it was dry I doubt I would be any faster, maybe a second or two at best.   

06.02.001.40sec.wmv


Since these runs were done with a proper set-up from stand still and finish in the box,  they are a bit slower compared to my previous timed runs, which were done with rolling start and no finish box. 

I'm hitting my plateau really hard.  Most of my runs were 43 seconds, scary in consistency. I'm maintaining a relatively clean line most of the time.  I'm leaning the bike to a degree I'm comfortable with and sometimes beyond that  (a few scrapes on my leather suit to prove that). 

I'm definitely missing something though.  Reviewing my runs,  most of them look brisk and smooth, but they just do not look  "right"   as compared to the Japanese counterparts.   

I'm hoping to see my run as a slower mirror of a Japanese rider's run, but I'm seeing a completely different overall picture. 

I'm also starting to question the "offset"  entry line into the cones.  The more I think about it, the less it makes sense.  If I'm offsetting my entry  to the cone so that its as wide as I'm comfortable with, then how is it different in terms of distance traveled and time,  if I just ride around the cone?  If the figure 8's shape does not change, but only placement of the cones change INSIDE that figure eight, then whats the difference?

The way I understand, to gain time,  at the slowest part of the 8, near the cones,  I need to swing the bike around as fast as I can to travel shortest distance around the cone, while being at the slowest speed of the lap, to maintain traction and not wipe out. 

Simply riding around the cone as I would in a bend, by just leaning the bike into the turn,  doesn't work because I'm covering too much distance and even if I'm doing it fast, it eats up time.

Riding the rear wheel, by leaning it so that it swings around the cone in a tightening spiral  requires  a very precise combination of speed and lean angle.   Too much speed and you are running wide.  Too much lean angle, and not enough speed and gravity takes over and your drop your bike. 

Call me crazy, but I'm still seeing  Japanese riders, swinging their bikes around their rear wheel.  Basically circling their front wheel and at a larger arc, while rear wheel travels only few inches.   This gives them the ability to swing their bike around as fast as they can around the cone, and be one the gas faster to the next cone, in the shortest possible distance.

I'm trying my hardest to do that,  but I'm not seeing anything like that,  in my clips.  I'm still seeing my rear wheel traveling a wide arc around the cone,  when  it should be almost stationary near the cone, and the front swinging around it.   

I'm hard on my rear brake to a point where after a few runs, I'm boiling my brake fluid and have to let it cool down so I can use rear brakes again. 

One thing I did notice in my body posture, is that its much better to lean forward into a more sporty body position.  That way  arms get bet at the elbows more, and I get a lot more freedom to move them around with the bars to the full lock.  It gives me a bit more control and freedom of movement.
 

I'll try to get a session in,  tomorrow in the morning as well. Hopefully we won't get any rain during the night, so pavement will be dry. 

I keep referring back to this video

GSX−R1000で回転.mov


And the answer has to be in there somewhere.   Lean angle, speed and rear brake.   He maintains that tight radius around the cone, while I can not. 

Vulfy

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Re: Vulfy's video thread
« Reply #18 on: June 02, 2012, 08:08:35 PM »
Same rider.

111010千種練習会GSX-R1000おまけ.MP4

Springer

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Re: Vulfy's video thread
« Reply #19 on: June 02, 2012, 09:04:24 PM »
 It would be nice if you had some dust or pollen on the pavement. That way you could "see" the track of your tires. Member Ironsled works at a power plant (its a dusty place). He has some interesting pictures of his tire tracks in the parking lot there.

Vulfy

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Re: Vulfy's video thread
« Reply #20 on: June 02, 2012, 09:33:17 PM »
hmmmm......

cue the MacGyver music

Motogymkhanaman

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Re: Vulfy's video thread
« Reply #21 on: June 03, 2012, 07:09:22 AM »
I am often asked by riders why it is that we should have a big offset at the entry to a pylon so that we can be close to it at the exit. In the GP8 challenge, it is true to say that so long as the track is correct, then it doesen't really matter where the pylon is in relation to the track. However, this is not true when it comes to negotiating a Moto Gymkhana course in the shortest possible time. Imagine an offset slalom running from left  to right relative to an observer at the side of the course. As a rider enters the slalom, the observer points towards the bike and tracks the bike with their finger as it negotiates the slalom. If the rider has done things correctly then the observers finger should constantly be moving in the same direction. but if at any time the observers finger moves back in the opposite direction then it is easy to see that the rider is taking two steps forward and one step back. As can be imagined, a rider showing this retrograde motion loses a significant amount of time in comparison to a rider that is always moving forward. This is the reason for the wide in-close out technique as it ensures that the bike is, as far as possible, always moving forward in the obstacle.

We also get a lot of concern from our riders why videos of their attempts at GP8 look nowhere near those of the Japanese riders. Our friend Mr Kimura provides a good explanation in that it is all down to the 'rotation time', or the amount of time it takes a rider to complete a 360 degree circle around a pylon. Most novice riders will typically take between 6 and 8 seconds to complete a rotation, yet riders like Yoshinobu Shiga can manage the same task in 2.5 seconds! Our friend on the GSXR1000 in the video clip is managing a rotation in about 3 seconds, which is about right for a rider in C1 class. Kimura-san tells us that the fastest rotation occurs when the bike is at full lock and near maximum bank angle, but with the least possible tyre slip angle(?). To get to this state of Full-Rock as our Japanese friends amusingly call it requires lots of practice, but also an understanding of the forces acting on the bike. Take the coin we used to demonstrate spiral tracks only this time get it spinning on the spot. As the energy decays the coin will start to lean, but due to the fact that there is no horizontal force acting on it, it doesen't shoot off across the table, but simply rotates around its circumference until it eventually falls over. This is a good demonstration of zero slip angle which can only occur with zero horizontal thrust. Our bikes can never achieve this perfect state as there is a whole chunk of machinery (and another wheel) sticking out in front of the rear tyre and if there was no horizontal thrust, the bike wouldn't go anywhere.

The lean angle, speed, turn radius combination works only with slip angles greater than zero, otherwise a bike that is going at 100 mph and leaning over at 45 degrees without any slip angle would constantly be trying to highside in the opposite direction to the turn as it tries to rapidly change direction. The key to the problem therefore is one of speed (horizontal thrust). Lots of speed and lots of bank means lots of slip angle, low speed and lots of bank means low slip angle and it is this state that is the perfect one to be in to make fast rotations. In all the videos of the Japanese riders you will notice that the bike isn't actually going very fast, but it is changing direction (rotating) very quickly indeed.

Mr Kimura says that "if you try and go fast, you will end up going slow" and nowhere is this better illustrated than during the rotation. The trick is to slow the bike far more than you might currently do because minimum slip means maximum rotation. During the GP8 we blast between the pylons as fast as possible and then lose pretty well all of that speed so we can practically fall around the pylon as we are going so slow. The skilled rider can tread the fine line between going slow enough to achieve the maximum rotation, but not so slow that the bike capsizes completely and falls over.

This as can be imagined is a very advanced technique and not one we recommend for riders who are concerned about damaging their bike as it is all too easy to get the rotation speed horribly wrong and end up crashing to the ground.


BillZ

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Fantastic Thread
« Reply #22 on: June 03, 2012, 08:38:15 AM »
V:  I don't know if I am ever going to be able to catch you, in your analysis of the technical aspects of "Full Rock."  I am impressed with how well you have verbalized the aspects of this issue and, despite your sense of hitting a performance plateau, I feel like you have moved far ahead of me.  The commentary that Mogogymkhanaman has added to your analysis is extremely insightful and timely for those of us trying to learn new technique.

I don't agree that the rear tire is standing still in the turn around the cone, but will agree with your example video that the rear tire tracks a much smaller radius circle around the cone.

Wonderful examples and great advice.  I wish I had something productive or helpful to add to this discussion.  I look forward to putting these techniques into practice as soon as possible.
Lean into it...

Vulfy

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Re: Vulfy's video thread
« Reply #23 on: June 03, 2012, 08:00:08 PM »
Motogymkhanaman:   Thank you for that input.  I think in my current situation its a basic concept of "no balls, no glory"   ;D
I'm still struggling with the butterflies in my stomach when really leaning my bike  in a slow turn and locking in the bars.  I think I have a couple of ideas for practice routine to get me more comfortable and proficient with those lean angles at those speeds. 

And my eyes were not deceiving me,  Japanese riders do want to swing their front wheel around rear, to turn the bike 180 degrees around the cone in the least distance possible. 

What you are saying about offset entry does make sense for riding a course.  Its a basic wide in, tight apex, wide out concept that is applied to most turns on a track or a more aggressive ride on the street.  Doing it in GP8 just enforces a good habit of proper line.  Got it. 

Also in Gymkhana it seems that its a very fine balance of speed and distance.  You haul ass in the straights or wide turns  for speed, but  in tighter spots,  distance is the king,  so you drop your speed to tighten turns, and keep traveled distance around cones to a minimum.   
A very  yin/yang,  zen sort of a thing.  I like it !    8)

If all of this information and more is in your upcoming book then this is priceless.  Count me in for any support and a copy! 

Elessar:  Just thinking out loud.  I'm extremely lucky to be able to find support and advice from other riders who are more advanced and know what they are talking about, in such niche sport as Gymkhana.   Happy to pass and share the knowledge and my personal experience to others who are also interested. 






ironslede68

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Re: Vulfy's video thread
« Reply #24 on: June 04, 2012, 01:24:29 AM »
It would be nice if you had some dust or pollen on the pavement. That way you could "see" the track of your tires. Member Ironsled works at a power plant (its a dusty place). He has some interesting pictures of his tire tracks in the parking lot there.


thanks for reminding me springer, it's now here, ya'll have fun

http://amgrass.com/forum/video-pics/tire-arc-deviation-disscussion/
A timid person is frightened before a danger; a coward during the time; and a courageous person afterward. -- Jean Paul Richter

Springer

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Re: Vulfy's video thread
« Reply #25 on: June 04, 2012, 08:01:35 AM »
It would be nice if you had some dust or pollen on the pavement. That way you could "see" the track of your tires. Member Ironsled works at a power plant (its a dusty place). He has some interesting pictures of his tire tracks in the parking lot there.


thanks for reminding me springer, it's now here, ya'll have fun

http://amgrass.com/forum/video-pics/tire-arc-deviation-disscussion/



 thumbs up

BillZ

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Re: Vulfy's video thread
« Reply #26 on: June 04, 2012, 12:48:32 PM »
I too am looking forward to a copy of that book when it's released.
Lean into it...

Vulfy

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Re: Vulfy's video thread
« Reply #27 on: June 04, 2012, 11:19:57 PM »
... interesting choice of music, but EXTREMELY helpful video in slow motion.

二輪ジムカーナ 8の字練習 Shinさん


He has a few slow motion videos.

Vulfy

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Re: Vulfy's video thread
« Reply #28 on: June 04, 2012, 11:28:19 PM »
二輪ジムカーナ 8の字練習 つがたくさん
« Last Edit: June 04, 2012, 11:29:54 PM by Vulfy »

Motogymkhanaman

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Re: Vulfy's video thread
« Reply #29 on: June 05, 2012, 04:40:39 AM »
These two videos are wonderful training aids and we have used them a lot to identify what's going on and when. It is a good idea to run through the videos studying just one bit at a time, rather than trying to absorb everything. The first and most important thing to study is the positioning of the riders heads and when they are turned and in what direction. Next check out the handlebars and when and by how much they are being turned. Then look at the direction the front wheel is pointing especially in relation to the throttle being opened. See which bit of the bike is closest to the pylon and when, then check the rate of change in the bank angle and the riders body position (sideways as well as fore and aft) in relation to it. sadly it's not very easy to see when and where the brakes are coming on and off, so I will try and find another video of the chap on the NSR, which luckily for us has very noisy brakes.

By chopping things up into their component parts, understanding what's going on becomes very much easier. It's also very good to compare the techniques in consideration of the type of bike, the big and heavy XJR and the light and agile NSR.