The pedaling technique thread

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Jun 18, 2015
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Wow, you really got a lot of info from looking at one pic! Our data show no difference in hip position for the two conditions.


JayKosta said:
From the Fig 1 photo, it appears the cyclist achieved the 'instructed position' by sitting more forward on the saddle and has his body 'center of mass' changed from being behind the bottom bracket spindle, to being over the spindle.
Do you recall if the other participants did the same position change?

Jay Kosta
Endwell NY USA
 
Jun 4, 2015
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PhitBoy said:
backdoor said:
"Off the bike, stand up, knees slightly bent, one foot slightly ahead like your cranks are at 3 and 9, and bend over forward 90 degrees, arms out like you're on the saddle. Now stay there.
You should feel your weight being carried by your core/abs. That's what it should feel like on the bike, go out in a parking lot and practice. Ride around without gripping around the bar, using only your fingertips. Heavy feet, light hands. Try to carry the weight in a split between the saddle and legs."
We've done that study! Only reported as a conference poster and need to write up the full manuscript. Reducing the weight on the hands increases the relative contribution of power from hip extension and reduces the contribution from knee extension. Its not in the abstract but when we told subjects to lean heavily on the bars, the contribution from knee extension went up. In other words, the more weight on your hands, the more you're using your quads.
ACSM%202012%20-%20Hip%20Extension_zpsrdyiqyri.jpg

Would you get the same results if riders were in the more aero lower drops position?
 
Jun 4, 2015
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JayKosta said:
From the Fig 1 photo, it appears the cyclist achieved the 'instructed position' by sitting more forward on the saddle and has his body 'center of mass' changed from being behind the bottom bracket spindle, to being over the spindle.
Do you recall if the other participants did the same position change?

Jay Kosta
Endwell NY USA

More about taking weight off the bars, complicated and not for those with bad backs.
https://www.youtube.com/watch?v=tVlcjl05epA
 
Jul 4, 2009
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....youse may find this useful/interesting....

Why we walk on our heels instead of our toes: Longer virtual limbs

“Humans are very efficient walkers, and a key component of being an efficient walker in all kind of mammals is having long legs,” Webber said. “Cats and dogs are up on the balls of their feet, with their heel elevated up in the air, so they’ve adapted to have a longer leg, but humans have done something different. We’ve dropped our heels down on the ground, which physically makes our legs shorter than they could be if were up on our toes, and this was a conundrum to us (scientists).”

Webber’s study, however, offers an explanation for why our heel-strike stride works so well, and it still comes down to limb length: Heel-first walking creates longer “virtual legs,” he says.

We Move Like a Human Pendulum

When humans walk, Webber says, they move like an inverted swinging pendulum, with the body essentially pivoting above the point where the foot meets the ground below. As we take a step, the center of pressure slides across the length of the foot, from heel to toe, with the true pivot point for the inverted pendulum occurring midfoot and effectively several centimeters below the ground. This, in essence, extends the length of our “virtual legs” below the ground, making them longer than our true physical legs.

As Webber explains: “Humans land on their heel and push off on their toes. You land at one point, and then you push off from another point eight to 10 inches away from where you started. If you connect those points to make a pivot point, it happens underneath the ground, basically, and you end up with a new kind of limb length that you can understand. Mechanically, it’s like we have a much longer leg than you would expect.”

http://www.aetrexblog.com/healthy-living/why-we-walk-on-our-heels-instead-of-our-toes-longer-virtual-limbs/?utm_source=salesforce&utm_medium=email&utm_campaign=footprints-6-26&utm_term=lead-blog-article

Cheers
 
Rough roads question..I am finding that while going over really bumpy chit, that the big ring is better? Even at the same speed I find that switching from small to large makes bumps less noticeable..?It could be the lower cadence or that pressure on the pedals has my cheeks slightly raised from the seat..? I have no idea why it is better.. or why I shifted up to begin with.. but it feels better..
 
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Unchained said:
Rough roads question..I am finding that while going over really bumpy chit, that the big ring is better? Even at the same speed I find that switching from small to large makes bumps less noticeable..?It could be the lower cadence or that pressure on the pedals has my cheeks slightly raised from the seat..? I have no idea why it is better.. or why I shifted up to begin with.. but it feels better..
You are correct. By shifting to higher gear it reduces the rear wheel spinning and losing contact with road over the bumps. That is why higher volume tires at lower psi on bumpy roads are better
 
Jun 4, 2015
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CoachFergie said:
People pedal differently at different power outputs relative to their ability and experience. Nooooooooooooo!


http://fitwerx.com/why-power-based-bike-fitting-doesnt-work/

The objectives given to your brain control your pedalling muscle firing patterns, not bike fitting or equipment change. Powercrank research proved that with riders reverting back to their old natural style when PC's were removed.
Cyclists should pedal differently depending on the type of pedal power they require, sustainable semicircular for TT's and mashing for sprinting.
 
The take home from Fernandez-Pena paper where the athletes went from normal cranks to gimmick cranks and adapted to the gimmick cranks and then went back to normal cranks and adapted is that WE adapt.

Any decent coach or biomechanist will tell you that trying to fight this is futile.
 
Jun 4, 2015
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CoachFergie said:
The take home from Fernandez-Pena paper where the athletes went from normal cranks to gimmick cranks and adapted to the gimmick cranks and then went back to normal cranks and adapted is that WE adapt.

Any decent coach or biomechanist will tell you that trying to fight this is futile.

Using PC's your ineffective weakest muscles are doing what they are forced to do in an awkward and sometimes painful way, on your return to standard cranks you can forget about these weakest muscles and let your brain/muscles return to its natural and easier way of pedalling.
Why does peak torque for many riders occur after 3 o'c ?
 
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CoachFergie said:
Because they are responding to the constraints of the cranks, bikes, gearing, and where they are riding. This is pretty simple stuff Noel.
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I don't think it is 'pretty simple stuff' because in a person-to-person comparison it is likely that there are many details that all contribute to precisely where max torque is produced.
Items such as: joint angles, limb length, limb weight, individual muscle strength, etc.
Max torque at 3 o'clock only looks likely if the force on the pedal is assumed to always be vertical.

Jay Kosta
Endwell NY USA
 
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CoachFergie said:
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Let me know of any National High Performance programme or Professional team that spend any time coaching pedalling technique!!!
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Yes the actual pedalling done by an individual can seem simple to them - they just
'do whatever it takes'.
But that doesn't mean the details of what is involved in the action are simple. Nor does it means that everyone does it equally well.

Regarding coaching of pedalling technique - do you coach or assist your riders about things such as their saddle and handlebar height and position, and crankarm length with the goal of improving power, endurance, speed, etc.?
I don't know what is done at the national or professional level, so I'll trust your answers about what you do for the riders who you coach.

Jay Kosta
Endwell NY USA
 
Where there is evidence, I use the evidence, estimates of the effect of different crank lengths, different pedalling approaches, equipment to change the pedalling technique have proved to be very small or just not there. Where there is no research we look at best practice.

My money, having just coached a rider to the 20th World Level medal at Junior Worlds Track Champs in Italy, is still on trying to sustain power better for the event duration rather than trying to increase power.
 
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backdoor said:
How do cranks constrain a rider's pedalling ?
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Typically the 'ball of the foot area' is firmly held a small distance above the axle of the pedal. And that distance is forced to remain constant (constrained) during the full rotation of the crank. Through ankle movement the rider can (and does) make small changes in the precise angle of the foot above the axle - but the rider cannot change the basic circular movement of the foot around the bottom bracket spindle.
For example, the foot is prevented (constrained) from moving diagonally UP from the 7 o'clock position to the 1 o'clock position.

Jay Kosta
Endwell NY USA
 
Jun 4, 2015
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JayKosta said:
backdoor said:
How do cranks constrain a rider's pedalling ?
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Typically the 'ball of the foot area' is firmly held a small distance above the axle of the pedal. And that distance is forced to remain constant (constrained) during the full rotation of the crank. Through ankle movement the rider can (and does) make small changes in the precise angle of the foot above the axle - but the rider cannot change the basic circular movement of the foot around the bottom bracket spindle.
For example, the foot is prevented (constrained) from moving diagonally UP from the 7 o'clock position to the 1 o'clock position.

Jay Kosta
Endwell NY USA
 
Jun 4, 2015
785
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3,280
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JayKosta said:
backdoor said:
How do cranks constrain a rider's pedalling ?
----------------------
Typically the 'ball of the foot area' is firmly held a small distance above the axle of the pedal. And that distance is forced to remain constant (constrained) during the full rotation of the crank. Through ankle movement the rider can (and does) make small changes in the precise angle of the foot above the axle - but the rider cannot change the basic circular movement of the foot around the bottom bracket spindle.
For example, the foot is prevented (constrained) from moving diagonally UP from the 7 o'clock position to the 1 o'clock position.

Jay Kosta
Endwell NY USA

How would that 'diagonal taking up' improve your pedalling?