Go Back  Bike Forums > Bike Forums > Road Cycling
Reload this Page >

Downhill technique: Flairing one's knee

Notices
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 03-09-20, 10:21 PM
  #1  
Robert A
Senior Member
Thread Starter
 
Join Date: Sep 2012
Location: Los Angeles
Posts: 752

Bikes: 2019 CAAD12, 2015 Specialized Sirrus Comp

Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 559 Post(s)
Likes: 0
Liked 63 Times in 45 Posts
Downhill technique: Flairing one's knee

I've been looking for techniques to improve downhill speed and noticed that professional riders point their inside knee into the turn. In other words, if the curve is to the right, they flair their right knee away from the bike.

Why is this done and how does it help? Is the objective to somehow shift one's center of gravity?
Robert A is offline  
Old 03-09-20, 11:06 PM
  #2  
DrIsotope
Non omnino gravis
 
DrIsotope's Avatar
 
Join Date: Feb 2015
Location: SoCal, USA!
Posts: 8,553

Bikes: Nekobasu, Pandicorn, Lakitu

Mentioned: 119 Post(s)
Tagged: 0 Thread(s)
Quoted: 4905 Post(s)
Liked 1,731 Times in 958 Posts
I'm no professional, so I'm gonna guess two things: Unloading the inside pedal, as most of the rider's weight should be on the outside pedal, and the angling of the knee is to allow the torso to get lower to the ground, lowering the center of gravity.

Or maybe it's just more comfortable. I've always angled the inside knee toward the turn unconsciously. Though it seems easier to load the outside pedal with the inner leg "kicked out."
__________________
DrIsotope is offline  
Old 03-09-20, 11:15 PM
  #3  
HTupolev
Senior Member
 
Join Date: Apr 2015
Location: Seattle
Posts: 4,261
Mentioned: 41 Post(s)
Tagged: 0 Thread(s)
Quoted: 1971 Post(s)
Liked 1,297 Times in 629 Posts
Partly because it feels good, sometimes because it also indicates turn intent if done early. I think.

Motorcyclists do it to gauge lean angle, but this tactic doesn't apply to road bikes. If the bicycle is leaned far enough that you can touch the ground with your knee, you've already slid out. (And, dragging a bare or lycra-clad knee against pavement would be a poor choice regardless.)

It doesn't seem to create any problems, so go ahead and do it if you like doing it.
HTupolev is offline  
Old 03-09-20, 11:16 PM
  #4  
smashndash
Senior Member
 
Join Date: Feb 2018
Posts: 1,410

Bikes: 2017 Specialized Allez Sprint Comp

Mentioned: 11 Post(s)
Tagged: 0 Thread(s)
Quoted: 850 Post(s)
Liked 344 Times in 247 Posts
I’m pretty sure your leg naturally falls that way, no? If you lean, gravity pulls your leg outward.

You could keep your knee in, but then you’re fighting gravity. It’s not stable. Pushing your knee outward is basically going with the flow.

Or maybe we just like to think we’re motoGP riders, who put their knees out to know when they’re about to scrape hard parts

One time I railed a corner harder than I anticipated and unclipped my foot I’ve reined in that habit since but I still do it.
smashndash is offline  
Old 03-09-20, 11:32 PM
  #5  
Robert A
Senior Member
Thread Starter
 
Join Date: Sep 2012
Location: Los Angeles
Posts: 752

Bikes: 2019 CAAD12, 2015 Specialized Sirrus Comp

Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 559 Post(s)
Likes: 0
Liked 63 Times in 45 Posts
Originally Posted by smashndash
I’m pretty sure your leg naturally falls that way, no? If you lean, gravity pulls your leg outward.

You could keep your knee in, but then you’re fighting gravity. It’s not stable. Pushing your knee outward is basically going with the flow.
I'm not entirely sure that's correct. When you're in turn, I believe the center of gravity is down the center of the bike, not outward into the center of the turn.
Robert A is offline  
Old 03-09-20, 11:34 PM
  #6  
Robert A
Senior Member
Thread Starter
 
Join Date: Sep 2012
Location: Los Angeles
Posts: 752

Bikes: 2019 CAAD12, 2015 Specialized Sirrus Comp

Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 559 Post(s)
Likes: 0
Liked 63 Times in 45 Posts
Originally Posted by DrIsotope
I'm no professional, so I'm gonna guess two things: Unloading the inside pedal, as most of the rider's weight should be on the outside pedal, and the angling of the knee is to allow the torso to get lower to the ground, lowering the center of gravity.

Or maybe it's just more comfortable. I've always angled the inside knee toward the turn unconsciously. Though it seems easier to load the outside pedal with the inner leg "kicked out."
Please explain why the rider's weight should be on the outside pedal and not the inside one. Is there a benefit to shifting one's weight to the outside of the turn?
Robert A is offline  
Old 03-10-20, 12:00 AM
  #7  
smashndash
Senior Member
 
Join Date: Feb 2018
Posts: 1,410

Bikes: 2017 Specialized Allez Sprint Comp

Mentioned: 11 Post(s)
Tagged: 0 Thread(s)
Quoted: 850 Post(s)
Liked 344 Times in 247 Posts
Originally Posted by Robert A
I'm not entirely sure that's correct. When you're in turn, I believe the center of gravity is down the center of the bike, not outward into the center of the turn.
Sorry please explain further. I didn’t mean center of gravity. I just meant the force of gravity.

Also... what do you mean the center of gravity is down the center of the bike? I’m fairly certain that is not true except when you are going in a straight line.
smashndash is offline  
Old 03-10-20, 12:04 AM
  #8  
smashndash
Senior Member
 
Join Date: Feb 2018
Posts: 1,410

Bikes: 2017 Specialized Allez Sprint Comp

Mentioned: 11 Post(s)
Tagged: 0 Thread(s)
Quoted: 850 Post(s)
Liked 344 Times in 247 Posts
Originally Posted by Robert A
Please explain why the rider's weight should be on the outside pedal and not the inside one. Is there a benefit to shifting one's weight to the outside of the turn?
You never want to have your inside pedal down because it will clip the road. So this means either you’re gonna be horizontal, or have your outside foot down. Horizontal is not a stable system. You need to have equal weight on your left and right foot, or your pedals will move. Putting your body weight on your lower aka outside pedal is a stable system. Your foot is not moving from there.

The reason you would put weight on the pedal instead of your saddle and bars is because that is where your center of mass is. By putting all of your weight near your center of mass, your bike can buck underneath you in response to bumps etc. You’ve probably heard that you should keep your arms loose.

Weight on outside pedal, arms loose, and light on the saddle means less of a chance for a bump to upset you and your bike.
smashndash is offline  
Likes For smashndash:
Old 03-10-20, 07:22 AM
  #9  
DaveSSS 
Senior Member
 
Join Date: Sep 2008
Location: Loveland, CO
Posts: 7,213

Bikes: Cinelli superstar disc, two Yoeleo R12

Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 1090 Post(s)
Liked 554 Times in 443 Posts
Flaring your knee is a worthless exercise. Weighting the outside pedal will place a little more weight on the front tire, which can't hurt. Learning how to steer properly is the problem for riders with no motorcycle experience or training. Start with the fact that counter steering is required to keep the bike turning and the fact that the bike wants to go in a straight line with no steering input. A bicycle requires so little effort to steer that all sorts of strange ideas exist about steering a bicycle. The most common is that that countersteering only initiates the turn and after that, no additional counter steering is needed. Any motorcycle rider with experience with on winding mountain roads knows better.
DaveSSS is offline  
Likes For DaveSSS:
Old 03-10-20, 07:23 AM
  #10  
Robert A
Senior Member
Thread Starter
 
Join Date: Sep 2012
Location: Los Angeles
Posts: 752

Bikes: 2019 CAAD12, 2015 Specialized Sirrus Comp

Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 559 Post(s)
Likes: 0
Liked 63 Times in 45 Posts
Originally Posted by smashndash
Sorry please explain further. I didn’t mean center of gravity. I just meant the force of gravity.

Also... what do you mean the center of gravity is down the center of the bike? I’m fairly certain that is not true except when you are going in a straight line.
I mean the force of gravity, too. When you lean right in a turn, the centrifugal force to the left is counteracting the lean. The force is lined up with the tilt of the bike. If it was to the right, you'd fall right over.
Robert A is offline  
Old 03-10-20, 07:26 AM
  #11  
smashndash
Senior Member
 
Join Date: Feb 2018
Posts: 1,410

Bikes: 2017 Specialized Allez Sprint Comp

Mentioned: 11 Post(s)
Tagged: 0 Thread(s)
Quoted: 850 Post(s)
Liked 344 Times in 247 Posts
Originally Posted by Robert A
I mean the force of gravity, too. When you lean right in a turn, the centrifugal force to the left is counteracting the lean. The force is lined up with the tilt of the bike. If it was to the right, you'd fall right over.
Ah yeah. This is true. Idk. I can’t claim to have a scientific reason for putting my knee out but I would say that if you’re not doing it naturally, doing it forcibly isn’t gonna make you faster. The #1 thing you can do to improve your downhill skills is get nicer tires and #2 is follow someone you trust


but you have piqued my curiosity. I’m going to try descending without flaring my knee and see what happens. Maybe I’ll update. My guess is that, psychologically, it helps me keep track of how hard I’m leaning, regardless of whether I scrape. Motorcyclists do this even when they don’t intend to get anywhere near knee-scraping territory. Some motorcycles can’t.

Last edited by smashndash; 03-10-20 at 07:31 AM.
smashndash is offline  
Old 03-10-20, 07:34 AM
  #12  
Lemond1985
Sophomore Member
 
Lemond1985's Avatar
 
Join Date: Jan 2019
Posts: 2,690
Mentioned: 12 Post(s)
Tagged: 0 Thread(s)
Quoted: 1628 Post(s)
Liked 1,057 Times in 631 Posts
I use the knee out to control the amount of lean.


Lemond1985 is offline  
Likes For Lemond1985:
Old 03-10-20, 07:38 AM
  #13  
Robert A
Senior Member
Thread Starter
 
Join Date: Sep 2012
Location: Los Angeles
Posts: 752

Bikes: 2019 CAAD12, 2015 Specialized Sirrus Comp

Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 559 Post(s)
Likes: 0
Liked 63 Times in 45 Posts
Lemond: What is the objective in controlling the amount of lean? To me, it seems you either sit along the centerline of the bike, or you shift your weight to one side. Is there an advantage either way?
Robert A is offline  
Old 03-10-20, 07:40 AM
  #14  
Robert A
Senior Member
Thread Starter
 
Join Date: Sep 2012
Location: Los Angeles
Posts: 752

Bikes: 2019 CAAD12, 2015 Specialized Sirrus Comp

Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 559 Post(s)
Likes: 0
Liked 63 Times in 45 Posts
Originally Posted by DaveSSS
Flaring your knee is a worthless exercise. Weighting the outside pedal will place a little more weight on the front tire, which can't hurt. Learning how to steer properly is the problem for riders with no motorcycle experience or training. Start with the fact that counter steering is required to keep the bike turning and the fact that the bike wants to go in a straight line with no steering input. A bicycle requires so little effort to steer that all sorts of strange ideas exist about steering a bicycle. The most common is that that countersteering only initiates the turn and after that, no additional counter steering is needed. Any motorcycle rider with experience with on winding mountain roads knows better.
What is counter steering, and how does adding weight to the outside pedal shift your weight to the front tire?
Robert A is offline  
Old 03-10-20, 07:42 AM
  #15  
Lemond1985
Sophomore Member
 
Lemond1985's Avatar
 
Join Date: Jan 2019
Posts: 2,690
Mentioned: 12 Post(s)
Tagged: 0 Thread(s)
Quoted: 1628 Post(s)
Liked 1,057 Times in 631 Posts
Counter-steering is where you quickly steer the opposite direction of a turn, going into the turn, in order to lean the bike over.

More lean = more turning action. Too much turning action = CRASH!
Lemond1985 is offline  
Old 03-10-20, 07:44 AM
  #16  
Robert A
Senior Member
Thread Starter
 
Join Date: Sep 2012
Location: Los Angeles
Posts: 752

Bikes: 2019 CAAD12, 2015 Specialized Sirrus Comp

Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 559 Post(s)
Likes: 0
Liked 63 Times in 45 Posts
Originally Posted by Lemond1985
More lean = more turning action. Too much turning action = CRASH!
So will a bike turn quicker if you shift your weight slightly to the outside of the turn?
Robert A is offline  
Old 03-10-20, 07:50 AM
  #17  
freeranger
Senior Member
 
freeranger's Avatar
 
Join Date: Jun 2005
Location: Kentucky
Posts: 2,579

Bikes: 06 Lemond Reno, 98 GT Timberline mtn.bike

Mentioned: 7 Post(s)
Tagged: 0 Thread(s)
Quoted: 421 Post(s)
Liked 690 Times in 430 Posts
I once owned a vintage motorcycle with non-folding footpegs. A friend and I used to race each other thru some fairly gnarly windy roads, and I would sometimes need to have the knee out so I could have the cycle more upright and get thru the corner without the footpeg getting too close to hitting the pavement. It's carried over to my bicycle riding. I have slightly dragged a pedal on my road bicycle going around a corner, guess I should have had the pedal upward, but didn't.
freeranger is offline  
Old 03-10-20, 08:33 AM
  #18  
Cypress
Globo Gym lifetime member
 
Cypress's Avatar
 
Join Date: Jan 2006
Location: Salem, Oregon
Posts: 5,204

Bikes: Fast ones

Mentioned: 11 Post(s)
Tagged: 0 Thread(s)
Quoted: 410 Post(s)
Liked 614 Times in 306 Posts
Flaring the knee happens for a number of reasons... The biggest is because people see motorcyclists do it, so they do it on their bike.

The two biggest reasons I do it are to lower the center of gravity when leaned (small reason) and to open up my hips so I can look through the corner better while staying low (main reason).

Originally Posted by Robert A
So will a bike turn quicker if you shift your weight slightly to the outside of the turn?
No. Countersteering is just how you steer. Next time you're cruising around above 20 mph gently push forward on one side of the handlebar. The bike will instantly lean in the opposite direction you pushed. That's countersteering, and it has nothing to do with weight.
__________________
Cypress is offline  
Likes For Cypress:
Old 03-10-20, 08:40 AM
  #19  
Zaskar
Senior Member
 
Join Date: Sep 2008
Posts: 781
Mentioned: 12 Post(s)
Tagged: 0 Thread(s)
Quoted: 479 Post(s)
Liked 277 Times in 156 Posts
This thread is the epitome of "Don't believe everything you read on the internet." Keep the theories coming - this is awesome.
The leader so far: "indicates turn intent"
Zaskar is offline  
Likes For Zaskar:
Old 03-10-20, 09:35 AM
  #20  
Iride01 
I'm good to go!
 
Iride01's Avatar
 
Join Date: Jul 2017
Location: Mississippi
Posts: 14,811

Bikes: Tarmac Disc Comp Di2 - 2020

Mentioned: 50 Post(s)
Tagged: 0 Thread(s)
Quoted: 6100 Post(s)
Liked 4,732 Times in 3,262 Posts
Originally Posted by Zaskar
This thread is the epitome of "Don't believe everything you read on the internet." Keep the theories coming - this is awesome.
The leader so far: "indicates turn intent"
To me the discussion is like trying to make someone justify why they like the color red over the color blue.
Iride01 is offline  
Old 03-10-20, 10:11 AM
  #21  
big john
Senior Member
 
big john's Avatar
 
Join Date: Sep 2005
Location: In the foothills of Los Angeles County
Posts: 25,107
Mentioned: 8 Post(s)
Tagged: 0 Thread(s)
Quoted: 8191 Post(s)
Liked 8,851 Times in 4,396 Posts
Originally Posted by Robert A
I mean the force of gravity, too. When you lean right in a turn, the centrifugal force to the left is counteracting the lean. The force is lined up with the tilt of the bike. If it was to the right, you'd fall right over.
It's not centrifugal force which acts on us in a turn, it's centripetal force, ( opposing an object in motion tends to stay in motion ).
As to throwing your knee in the direction of a turn, try it at low speed. If I'm turning and need a little more impetus that way, I stick my knee out and it helps get me going into the turn. Maybe it's part mental, maybe it helps get my hips pointed the right way, idk. Try it.

Last edited by big john; 03-10-20 at 10:29 AM.
big john is offline  
Old 03-10-20, 10:22 AM
  #22  
indyfabz
Senior Member
 
indyfabz's Avatar
 
Join Date: Jan 2010
Posts: 39,059
Mentioned: 210 Post(s)
Tagged: 1 Thread(s)
Quoted: 18320 Post(s)
Liked 15,299 Times in 7,231 Posts
I do it because I think it looks impressive, especially to an old couple behind you in an RV while I am taming a rocky Mountain pass on my fully-loaded touring bike. They hang back and watch with amazement as I carve up each turn with flared knee, like your proud grandfather carving the turkey at Thanksgiving dinner. Once the rode straightens out, I move over and let them pass. It's not odd for them to applaud or even toss me a garland of roses as they do.
indyfabz is offline  
Old 03-10-20, 10:27 AM
  #23  
DaveSSS 
Senior Member
 
Join Date: Sep 2008
Location: Loveland, CO
Posts: 7,213

Bikes: Cinelli superstar disc, two Yoeleo R12

Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 1090 Post(s)
Liked 554 Times in 443 Posts
Originally Posted by Robert A
What is counter steering, and how does adding weight to the outside pedal shift your weight to the front tire?
Countersteering is more easily demonstrated on a motorcycle or mtb style bike. My instructor started out with push on the right side to lean the bike to the right and turn right. Quit pushing and the bike will straighten itself.

If the outer pedal is weighted, the weight moves from the saddle, that is further back, to the more forward center of the BB and more weight is on the front wheel. FWIW, I don't bother with it. I've ridden over 7000 miles of winding mountain descents with minimal braking and prefer to concentrate on steering.
DaveSSS is offline  
Old 03-10-20, 10:39 AM
  #24  
woodcraft
Senior Member
 
woodcraft's Avatar
 
Join Date: Apr 2012
Location: Nor Cal
Posts: 6,016
Mentioned: 17 Post(s)
Tagged: 0 Thread(s)
Quoted: 1814 Post(s)
Likes: 0
Liked 923 Times in 569 Posts
Flair: "a sense of style; dash"

Flare: "a curving outward"
woodcraft is offline  
Likes For woodcraft:
Old 03-10-20, 10:41 AM
  #25  
indyfabz
Senior Member
 
indyfabz's Avatar
 
Join Date: Jan 2010
Posts: 39,059
Mentioned: 210 Post(s)
Tagged: 1 Thread(s)
Quoted: 18320 Post(s)
Liked 15,299 Times in 7,231 Posts
Originally Posted by woodcraft
Flair: "a sense of style; dash"

Flare: "a curving outward"
As I note above, I flare with flair.
indyfabz is offline  

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service -

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.