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Downhill technique: Flairing one's knee

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Road Cycling “It is by riding a bicycle that you learn the contours of a country best, since you have to sweat up the hills and coast down them. Thus you remember them as they actually are, while in a motor car only a high hill impresses you, and you have no such accurate remembrance of country you have driven through as you gain by riding a bicycle.” -- Ernest Hemingway

Downhill technique: Flairing one's knee

Old 03-13-20, 12:01 PM
  #126  
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For anyone interested in research in the field, one reference is:

J. Fajans "Steering in Bicycles and Motorcycles", Am. J. Phys. 68 (7) July 2000

If you can't find a copy, or don't want to wade through the equations, here's an excerpt (emphasis mine):

In conclusion, a rider must lean a bike into a turn. Counter-steering and hip thrusts are two common ways of creating the lean, but other ways exist. The rider can take advantage of an uneven road surface, push harder on one pedal than the other, lean the bike over by the handlebars, accelerate with the wheel turned, or employ the growing oscillations shown in Fig. 5. In any event, gyroscopic forces play little role in leaning the bike over, through they do help set the steering angle. The appealing notion that gyroscopic forces are central to bike behavior, often repeated in papers and textbooks, is incorrect.
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Old 03-16-20, 11:33 AM
  #127  
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Flaring a knee is body english, and no more functional than follow-through on a golf club or graceful arcs over a keyboard, except as an air brake. If you had a full, tight fairing, you'd learn to manage just fine with steering alone. However, you might still not know how to describe it. Bicycling magazine once ran a major article postulating that in a fast descent, the handlebars are held perfectly still, and the turning accomplished by banking, apparently through some act of will.
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Old 03-16-20, 01:03 PM
  #128  
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Originally Posted by TricycleTom View Post
Flaring a knee is body english, and no more functional than follow-through on a golf club or graceful arcs over a keyboard, except as an air brake. If you had a full, tight fairing, you'd learn to manage just fine with steering alone. However, you might still not know how to describe it. Bicycling magazine once ran a major article postulating that in a fast descent, the handlebars are held perfectly still, and the turning accomplished by banking, apparently through some act of will.
As I mentioned above, at speed one simply drops one's head into the turn and the bike will follow. Try it.
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Old 03-16-20, 01:11 PM
  #129  
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Originally Posted by Carbonfiberboy View Post
As I mentioned above, at speed one simply drops one's head into the turn and the bike will follow. Try it.
Try dropping your head as if into a turn where there is no road, and see if the bike follows. Those things are SMART!
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Old 03-16-20, 01:13 PM
  #130  
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Originally Posted by TricycleTom View Post
Try dropping your head as if into a turn where there is no road, and see if the bike follows. Those things are SMART!
Yeah, yeah. Doesn't work on a tricycle. Not at all.
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Old 03-16-20, 01:25 PM
  #131  
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Countersteering explained (pick one):
https://www.youtube.com/results?sear...eer+motorcycle

As for sticking your inside knee out, not sure why you would do it on a bicycle, except it is a bit of a natural reaction when weighting the inside pedal which is what you want to do, not the outside. By doing so, you are moving your body inward, which moves the CG inward. This allows the bicycle to be more upright, which in turn, maintains a larger contact patch between your tire and the road. In the photo below, the blue lines show the slight decrease in lean angle of the bike in the rear.

https://photos1.meetupstatic.com/pho..._11323669.jpeg

This is why motorcycle racers do it, and it's the same reason why you would want to do it on a bike. If you are not leaned enough to make a difference (long, shallow sweeper) and you want to keep pedaling, then it's best to just stay in the saddle.

I ride motorcycles, and race at the club level and won a championship in 2014. So take my advice for what it's worth.
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Old 03-16-20, 01:36 PM
  #132  
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Originally Posted by Notso_fastLane View Post
...weighting the inside pedal which is what you want to do, not the outside...
This is a mistake people don't usually make too many times.
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Old 03-16-20, 01:41 PM
  #133  
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Originally Posted by kingston View Post
This is a mistake people don't usually make too many times.
It is somewhat understandable, as a lot of people go from riding BMX style bikes (and dirt-motorbikes) as kids. When riding on dirt, you tend to weight the outside and drop the inside leg for stability, often dragging the foot even around the corners. This still has the effect of moving one's CG inside if done properly, but lots of riders don't do it properly, and dirt tends to be much more forgiving than asphalt.

ETA: Thinking about the way I worded this, for clarity:

On a motorcycle, you don't have pedals that change height, so on a bicycle, you actually corner more like a dirtbike. You use your outside leg to support your weight, but you (should) move your CG inward. This way you get more clearance on the inside for cornering, both from the change of CG (shown in my previous post) and from the inside pedal being higher up and not in danger of hitting the ground.

Hope that makes more sense.

Last edited by Notso_fastLane; 03-16-20 at 01:56 PM.
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Old 03-16-20, 01:58 PM
  #134  
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Just out of curiosity, which championship did you win ?
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Old 03-16-20, 02:32 PM
  #135  
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Originally Posted by Notso_fastLane View Post
weighting the inside pedal which is what you want to do, not the outside.
You have it backwards. Weighting the outside pedal or peg on a dirt bike is what makes the rear wheel stick.

Ever see speedway? They don't even have an inside peg and they control the rear with their weight on the right peg.
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Old 03-16-20, 02:47 PM
  #136  
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Originally Posted by Notso_fastLane View Post
weighting the inside pedal which is what you want to do, not the outside
Bicycles do not have the clearance to weigh the inside pedal.

Relating motorcycles and bicycles is hard. When I was in college my friend and I would rip up a local twisty mountain on our motorcycles after class. He would beat me up the mountain, but then I'd beat him down the mountain because the throttle was no longer in control of the motorcycle relative to the uphill and my skills from the bicycle came into play.
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Old 03-16-20, 07:53 PM
  #137  
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Originally Posted by Notso_fastLane View Post
Countersteering explained (pick one):
https://www.youtube.com/results?sear...eer+motorcycle

As for sticking your inside knee out, not sure why you would do it on a bicycle, except it is a bit of a natural reaction when weighting the inside pedal which is what you want to do, not the outside. By doing so, you are moving your body inward, which moves the CG inward. This allows the bicycle to be more upright, which in turn, maintains a larger contact patch between your tire and the road. In the photo below, the blue lines show the slight decrease in lean angle of the bike in the rear.

https://photos1.meetupstatic.com/pho..._11323669.jpeg

This is why motorcycle racers do it, and it's the same reason why you would want to do it on a bike. If you are not leaned enough to make a difference (long, shallow sweeper) and you want to keep pedaling, then it's best to just stay in the saddle.

I ride motorcycles, and race at the club level and won a championship in 2014. So take my advice for what it's worth.
My motorcycle riding experience is extremely limited, so I won’t comment on how that works on a motorcycle ( where the vehicle ways 10 times more, the contact patch is dramatically bigger, and the power available is several orders of magnitude higher, but I’ve raced a ton of crits on a bicycle. And your take is 180 degrees off of my personal experience, and the teaching of every coach I’ve ever worked with.

i harken back to the greatest crit racers ever, including Davis Phinney, that would completely disagree with you.

Dont weight the outside pedal on a bike in a turn approaching the limits; stock up on tagaderm.
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Old 03-17-20, 08:09 AM
  #138  
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You want to raise the inner pedal for ground clearance, so you put the outer pedal down. To keep it down, you put weight on it, but the goal is to maintain pedal position, not to "shift your weight" for any strategic purpose.
As to the OP's original question, your inner knee can go anywhere. I used to tuck it in for better aerodynamics, but if I relaxed the leg my knee would naturally flop outward.

The whole counter-steering discussion seems like an off-topic distraction; I''m not sure how or why it keeps coming up. FWIW, you do have to force your bars against the turn during a fast corner - so you are counter-steering throughout. An observer can see this only at initiation, where the wheel is visibly pointing the "wrong" way. Watch any video of a racer in a fast, descending turn, and you'll see that the front wheel is not pointed into the turn - it's parallel to the bike frame, because the rider is forcing it to stay that way:

The rider here is pressing the right-hand bar against the turn, i.e. counter-steering. If he were to let go of the bars, he'd crash instantly as the front wheel flipped inward. Anybody who doubts this is free to do the experiment. (I suggest protective wear.)
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Old 03-17-20, 09:22 AM
  #139  
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Originally Posted by RedBullFiXX View Post
Just out of curiosity, which championship did you win ?
Washington Motorcycle Road Racing Association 2014 Lightweight Early GP.



Race Bike '09 Ninja 250R
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Old 03-17-20, 09:26 AM
  #140  
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Originally Posted by jpdemers View Post
You want to raise the inner pedal for ground clearance, so you put the outer pedal down. To keep it down, you put weight on it, but the goal is to maintain pedal position, not to "shift your weight" for any strategic purpose.
If you've ever slid the rear wheel on a road bike having your weight on the outside pedal is what will give you a chance to recover it. Have you drifted around on a mountain bike? You control the slide with the weighted pedal. Same effect on a dirt bike.

A friend was teaching me techniques to practice decades ago when I was trying to learn to ride dirt bikes. He would have us stand on the outside peg (completely off the saddle} and do "S" turns, shifting from one peg to the other. The theory was this would give you the instinct to throw you weight into the outside peg without thinking about it.
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Old 03-17-20, 09:28 AM
  #141  
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Originally Posted by Notso_fastLane View Post
Washington Motorcycle Road Racing Association 2014 Lightweight Early GP.
Race Bike '09 Ninja 250R
Great pic!
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Old 03-17-20, 09:28 AM
  #142  
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Weighting the inside pedal.

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Old 03-17-20, 09:45 AM
  #143  
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Originally Posted by LAJ View Post
Is this an example of what not to do?
I was waiting for some sparks.
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Old 03-17-20, 09:46 AM
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Originally Posted by LAJ View Post
Weighting the inside pedal.
Was waiting for the crash, then I realized the speeds weren't close to being high enough for leg position to matter.
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Old 03-17-20, 09:48 AM
  #145  
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Originally Posted by Cypress View Post
Was waiting for the crash, then I realized the speeds weren't close to being high enough for leg position to matter.
Exactly. He really is quite lucky.
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Old 03-17-20, 10:01 AM
  #146  
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I was wondering if he had a jacket in that backpack or maybe some leg warmers.
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Old 03-17-20, 11:18 AM
  #147  
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Originally Posted by Notso_fastLane View Post
Washington Motorcycle Road Racing Association 2014 Lightweight Early GP.
Race Bike '09 Ninja 250R
Those little 250's are a lot of fun !
But yeah, weight the outside pedal on a bicycle in corners
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Old 03-17-20, 11:42 AM
  #148  
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Originally Posted by LAJ View Post
This guy needs a jersey that says, "I HAVE NO IDEA WHAT I'M DOING".

Oh well, I did stupid stuff for years like riding with no lights at night, salmoning, and riding a frame three inches too tall. I survived somehow. It's a forgiving sport, evidently.
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Old 03-17-20, 12:57 PM
  #149  
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Originally Posted by Carbonfiberboy View Post
I think if a bicycle's geometry is perfect, one could take one's hands off the bars and continue on your line. But many bicycles aren't perfect and so we see bikes which will oversteer and understeer.
I think I would expand on your point a bit by saying that the bicycle/rider system is imperfect, since the rider on a bicycle is a far more significant component of the system than a rider on a motorcycle. A bicycle rider significantly outweighs his bicycle, air resistance is a more significant force during a turn (and is often varying throughout the turn), and you can't roll on power during a turn to "slingshot" through the turn. Note: I've ridden post on a motorcycle a couple of times, but never operated one.

Regarding the original post: I don't flare my knee during a turn, as many have stated I move my center of gravity forward, lean the bike/push on the inside hand on my handlebar (hard to tell if these are separate actions, or if leaning is in response to pushing with inside hand), and put my weight on the outside pedal. To tighten the turn radius I press on the inside hand and lean the bike more, to widen the turn radius I put less weight on my inside hand and lessen the lean angle.

I really doubt that pros use the knee to indicate where they're going. If the curve is to the right, for example, I doubt that the riders behind need the rider ahead of them to tell them that they are going right by pointing with their knee. Few bike riders are prone to flying off the road when there's a curve in the road - or, if they are, they aren't for long.
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Old 03-17-20, 01:29 PM
  #150  
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I think my namesake, is where I picked up the habit. This is Lemond in the '85 Coors Classic, on a high speed breakaway with Canadian Alex Steida at the Fisherman's Wharf Criterium. Lemond is using the "flaired" leg technique, while Steida seems to be using the more tucked technique. I would assume neither are very familiar with the course. Lemond always had a bit of a "funky" riding style, and probably still does.

Personally, I like using my leg to help steer me through complex corners, especially S-turns. There is a descent in coming down in into Portland OR from Skyline Blvd that has some wicked S turns, that would always throw me off after the second or third turn, and once you screw up your line on a set of S-turns you are hosed. By using my knee to steer on that hill, it reminded me which way to lean, as i have been known to get momentarily confused due to being not all that coordinated at times.

I think there are many ways to get down a mountain, as evidenced by the video above. I've been experimenting with the tucked leg technique, and agree that it's probably technically-superior. Most pros seem to favor it. I find I like it more the faster I'm going, whereas I flare my leg out more on the lower speed or technical stuff, but as always YMMV.
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