• The Cycling News forum is looking to add some volunteer moderators with Red Rick's recent retirement. If you're interested in helping keep our discussions on track, send a direct message to @SHaines here on the forum, or use the Contact Us form to message the Community Team.

    In the meanwhile, please use the Report option if you see a post that doesn't fit within the forum rules.

    Thanks!

The pedaling technique thread

Page 7 - Get up to date with the latest news, scores & standings from the Cycling News Community.
Mar 10, 2009
965
0
0
Visit site
FrankDay said:
2. increasing forces across the top quadrant (about 5-15%)
3. increasing forces across the bottom quadrant (about 0-10%)


How do PC's train these muscles used between 11-1 o'c, very little force is required to take the loose pedal/crank from 11 to 1 o'c, the same applies between 5-7 o'c. What muscles do you believe they are training. From your post it appears these are the only muscles PC's are supposed to be training as no training of muscles is needed for unweighting, so why the need for 6 months of continuous training.
 
Sep 23, 2010
3,596
1
0
Visit site
coapman said:
How do PC's train these muscles used between 11-1 o'c, very little force is required to take the loose pedal/crank from 11 to 1 o'c, the same applies between 5-7 o'c.
The same way they train the lifting portion of the stroke. If the rider doesn't do something active at this point in the stroke the cranks stop moving. Failing over the top is the most common failure after "transition" is seemingly accomplished.
What muscles do you believe they are training.
The muscles being trained depend upon the part of the stroke. Over the top it would primarily be the quads, which are already well trained so it isn't so much the muscles that are being trained there as the nervous system to start contraction of the muscle earlier than it is used to.
From your post it appears these are the only muscles PC's are supposed to be training as no training of muscles is needed for unweighting, so why the need for 6 months of continuous training.
Huh? Even if the muscles were perfectly trained from an aerobic perspective (which they usually aren't) when they came to us it would still take a long period of training to train the coordination. How long does it take to become proficient playing the piano? Or, to become expert in kicking a soccer ball?
 
Mar 10, 2009
965
0
0
Visit site
FrankDay said:
The same way they train the lifting portion of the stroke.




Correct, and these upstroke muscles are being trained by PC's not to apply torque but only to lift the effective weight of rising pedal/crank, on the return to standard cranks this lifting is no longer required, so normal un weighting action is resumed. The same applies at 12 and 6 o'c, here all they do is keep the crank moving with no application of additional torque. The most a rider can expect from these PC's is the circular style, the weakest of the pedalling techniques. So where does that leave that 40 % power increase, a figment of your imagination.
 
Sep 23, 2010
3,596
1
0
Visit site
As per usual, I have been thinking about how to better present what "pedaling in circles" really is (or should be). I think I have a much clearer explanation here: http://www.powercranks.com/icranks.html

If you don't want to read the entire explanation (sales pitch) then these two images I think do a pretty good job.
icranksexampleleftcircle.jpg

icranksexampleleftcirclegravity.jpg
 
Lets get some real science into this discussion lest others cherry pick data (and that's being generous) to fuel their confirmation bias.

Pedal force effectiveness in Cycling: a review of constraints and training effects
Rodrigo R Bini, Patria Anne Hume, James Croft, Andrew Edward Kilding

Abstract

Pedal force effectiveness in cycling is usually measured by the ratio of force perpendicular to the crank (effective force) and total force applied to the pedal (resultant force). Most studies measuring pedal forces have been restricted to one leg but a few studies have reported bilateral asymmetry in pedal forces. Pedal force effectiveness is increased at higher power output and reduced at higher pedaling cadences. Changes in saddle position resulted in unclear effects in pedal force effectiveness, while lowering the upper body reduced pedal force effectiveness. Cycling experience and fatigue had unclear effects on pedal force effectiveness. Augmented feedback of pedal forces can improve pedal force effectiveness within a training session and after multiple sessions for cyclists and non-cyclists. No differences in pedal force effectiveness were evident between summarized and instantaneous feedback. Conversely, economy/efficiency seems to be reduced when cyclists are instructed to improve pedal force effectiveness during acute intervention studies involving one session. Decoupled crank systems effectively improved pedal force effectiveness with conflicting effects on economy/efficiency and performance.

Keywords

pedal forces; pedaling technique; cycling performance; workload; pedaling cadence; body position
 
Analysis of the pedaling biomechanics of master’s cyclists: A preliminary study
William M Bertucci, Ahlem Arfaoui, Guillaume Polidori

Abstract

The crank torque represents the kinetics of the propulsive torque within the crank cycle. These kinetics are one of the important determinants of cycling performance. At our knowledge, works in literature concerning the pedaling pattern of master cyclist is lacking although this group of cyclists concerns the majority of practitioners. The purpose of this experimentation is to study the biomechanics of cycling in masters cyclists during an incremental test. Eleven trained masters cyclists (53.5 ± 4.1 years) have participated at this study. The results indicate that the master cyclists have a significant asymmetry (30 ± 8 to 23 ± 13 %) during the pedaling exercise at all power output level tested in this study (100, 150, 200 and 250 W). The present preliminary study suggests that the pedaling pattern asymmetry observed in the master cyclists should be taken into account to prevent knee or muscle overuse injuries.


Keywords

pedaling biomechanics; cycling; master population
 
Sep 23, 2010
3,596
1
0
Visit site
CoachFergie said:
Lets get some real science into this discussion lest others cherry pick data (and that's being generous) to fuel their confirmation bias.

Pedal force effectiveness in Cycling: a review of constraints and training effects
Rodrigo R Bini, Patria Anne Hume, James Croft, Andrew Edward Kilding

Abstract

Pedal force effectiveness in cycling is usually measured by the ratio of force perpendicular to the crank (effective force) and total force applied to the pedal (resultant force). Most studies measuring pedal forces have been restricted to one leg but a few studies have reported bilateral asymmetry in pedal forces. Pedal force effectiveness is increased at higher power output and reduced at higher pedaling cadences. Changes in saddle position resulted in unclear effects in pedal force effectiveness, while lowering the upper body reduced pedal force effectiveness. Cycling experience and fatigue had unclear effects on pedal force effectiveness. Augmented feedback of pedal forces can improve pedal force effectiveness within a training session and after multiple sessions for cyclists and non-cyclists. No differences in pedal force effectiveness were evident between summarized and instantaneous feedback. Conversely, economy/efficiency seems to be reduced when cyclists are instructed to improve pedal force effectiveness during acute intervention studies involving one session. Decoupled crank systems effectively improved pedal force effectiveness with conflicting effects on economy/efficiency and performance.

Keywords

pedal forces; pedaling technique; cycling performance; workload; pedaling cadence; body position
If only pedaling force effectiveness had any real world association to muscle effectiveness, the issue being that PFE does not take into account the forces that come from inertial effects and gravity. Until then any study that puts all of these forces together (muscle, inertial, gravity) and thinks they will see a correlation with efficiency and/or power will, most likely, be disappointed. perhaps, if the power is high, where the muscle force component is the major component, I guess there might be a chance of seeing something useful. Each study must be analyzed closely.

Edit: for instance, the authors make this statement in the paper:
In a mechanical perspective, applying pedal forces perfectly perpendicular to the crank in the direction of crank motion (force effectiveness equal to 100%) is only possible if a perfect circling action is performed by the cyclist.
Such a statement is simply wrong as demonstrated by my analysis of circular pedaling recent linked above. Circular muscle force pedaling action has nothing to do with circular measured pedal forces in a gravitational field.
 
Mar 10, 2009
965
0
0
Visit site
FrankDay said:
If only pedaling force effectiveness had any real world association to muscle effectiveness, the issue being that PFE does not take into account the forces that come from inertial effects and gravity. Until then any study that puts all of these forces together (muscle, inertial, gravity) and thinks they will see a correlation with efficiency and/or power will, most likely, be disappointed. perhaps, if the power is high, where the muscle force component is the major component, I guess there might be a chance of seeing something useful. Each study must be analyzed closely.

Edit: for instance, the authors make this statement in the paper:Such a statement is simply wrong as demonstrated by my analysis of circular pedaling recent linked above. Circular muscle force pedaling action has nothing to do with circular measured pedal forces in a gravitational field.


Gravity and inertia effect will always be there, so they can be dismissed as unimportant. After over 120 years of pedalling research no improvement has been made to pedalling performance due to the fact that all this research is nothing more than repetitive analysis of the same basic natural technique. When a new technique is discovered, you need a new definition of pedaling effectiveness and pedaling efficiency. I would consider pedaling effectiveness at any spot on the pedalling circle to be the percentage of 3 o'c force that can be applied at that spot and pedalling efficiency to be the torque return from that force. For example with the unnatural semi circular technique you can get 100% effectiveness and 100% efficiency at 1 o'c.
 
Sep 23, 2010
3,596
1
0
Visit site
coapman said:
Gravity and inertia effect will always be there, so they can be dismissed as unimportant.
While these will always be there and could, therefore, be considered unimportant they are important because they confuse any analysis because they are ignored yet present.
 
Mar 10, 2009
965
0
0
Visit site
FrankDay said:
While these will always be there and could, therefore, be considered unimportant they are important because they confuse any analysis because they are ignored yet present.



How does eliminating negatives on the back stroke increase force across the top ?
 
Sep 23, 2010
3,596
1
0
Visit site
coapman said:
How does eliminating negatives on the back stroke increase force across the top ?
If you will notice, the change in force is always a reasonably smooth transition (because of gravity a "perfect" circle muscle work torque application shows up as a sine wave torque application on the pedals) If one is starting the "top" force application at a "higher" level then it is "easy" to increase the force across the top over what it would have been if one had started at a lower level. Muscles only respond so fast so it is easier to get to a high level fast (and one has to react fast at a cadence of 90 or so) if one is starting at a higher level or starting sooner or both. One cannot go from nothing to maximum immediately regardless of what you think you do.
 
Mar 10, 2009
965
0
0
Visit site
FrankDay said:
If you will notice, the change in force is always a reasonably smooth transition (because of gravity a "perfect" circle muscle work torque application shows up as a sine wave torque application on the pedals) If one is starting the "top" force application at a "higher" level then it is "easy" to increase the force across the top over what it would have been if one had started at a lower level. Muscles only respond so fast so it is easier to get to a high level fast (and one has to react fast at a cadence of 90 or so) if one is starting at a higher level or starting sooner or both. One cannot go from nothing to maximum immediately regardless of what you think you do.



What does all of that got to do with the back stroke, as for going from nothing to maximum force immediately, it can be done, all that's required is the priming of the muscles involved during the upstroke, it would be impossible for a circular pedaler to make that instant change of force application because his brain is otherwise engaged. I believe PC's would be slowing you down in the transition from upward to forward crank movement.
 
Mar 10, 2009
965
0
0
Visit site
FrankDay said:
As per usual, I have been thinking about how to better present what "pedaling in circles" really is (or should be). I think I have a much clearer explanation here: http://www.powercranks.com/icranks.html

If you don't want to read the entire explanation (sales pitch) then these two images I think do a pretty good job.
icranksexampleleftcircle.jpg

icranksexampleleftcirclegravity.jpg


For torque application analysis purposes and also for perfecting pedalling technique, I prefer the sinusoidal graph as it is more revealing.
 
coapman said:
How does eliminating negatives on the back stroke increase force across the top ?
----------------
It all depends on where the negatives occur on the backstroke.
If there are negatives, or even a reduction of tangental force near the bottom of the stroke, then with the other leg, a portion of its force across the top is used to restore the force that was reduced.

If the negatives (or reduction) at the bottom are eliminated, then the entire force at the top appears as a 'net increase'.

Jay Kosta
Endwell NY USA
 
Sep 23, 2010
3,596
1
0
Visit site
coapman said:
For torque application analysis purposes and also for perfecting pedalling technique, I prefer the sinusoidal graph as it is more revealing.
Well, I used to prefer the cartesian coordinate analysis also. I have changed my mind as I think this gives a better big picture. They both provide the exact same data so, I guess, whatever floats your boat.
 
Sep 23, 2010
3,596
1
0
Visit site
JayKosta said:
----------------
It all depends on where the negatives occur on the backstroke.
If there are negatives, or even a reduction of tangental force near the bottom of the stroke, then with the other leg, a portion of its force across the top is used to restore the force that was reduced.

If the negatives (or reduction) at the bottom are eliminated, then the entire force at the top appears as a 'net increase'.

Jay Kosta
Endwell NY USA
It is my impression that most serious cyclists now do a reasonably good job across the bottom. A few start their negative force application as soon as 7 on the clock face but most get to 8 or 9 before negative forces are seen. It is coming across the top that is the big weakness of most riders, that I see. I think it is the top where the biggest gains can be made from technique improvements. However, such improvements cannot be made (or, at least, maximized) unless the negatives on the backstroke are improved or eliminated also.
 
Mar 10, 2009
965
0
0
Visit site
JayKosta said:
----------------
It all depends on where the negatives occur on the backstroke.
If there are negatives, or even a reduction of tangental force near the bottom of the stroke, then with the other leg, a portion of its force across the top is used to restore the force that was reduced.

If the negatives (or reduction) at the bottom are eliminated, then the entire force at the top appears as a 'net increase'.

Jay Kosta
Endwell NY USA




There is far more to be gained from concentrating only on the effective main power stroke and extending it from a third to a half of the pedalling circle than from trying to get some minimal positive results from the remaining ineffective two thirds.
 
coapman said:
There is far more to be gained from concentrating only on the effective main power stroke and extending it from a third to a half of the pedalling circle than from trying to get some minimal positive results from the remaining ineffective two thirds.
-----------
I basically agree with your 'half-stroke' method.

If high power is produced for a full 180 degrees of crank rotation, then I think there is some amount of positive force being produced prior to the 0 degree point, and after the 180 degree point - even though there isn't any concentration on producing high power at those points.

Extending the high power to full half-stroke reduces the ineffective portion from two thirds to near the one third portion where the other leg is doing its 'conventional power application'.

Jay Kosta
Endwell NY USA
 
My observation, after many years of watching pro cycling races, is they on the whole don't spin markedly smoother than the rest of us. You can tell this by watching the amount of motion in their upper bodies in response to pedaling (which would be near motionless if the effort in the descending pedal stroke matched that of the ascending stroke), and by listening to the uniformity of the song of their tyres and the zzhhhinng of their chain.
 
Seems that we are getting closer to the actual launch of the Garmin pedals that will measure application of power around the pedal stroke. Subject to validation of this the average user will be able to measure for themselves what numerous sport science labs have been measuring for the last 40 years. That trying to change the natural application of power around the pedal stroke has yet to be shown to improve the total power applied to the pedal at any duration.
 
Mar 10, 2009
965
0
0
Visit site
CoachFergie said:
That trying to change the natural application of power around the pedal stroke has yet to be shown to improve the total power applied to the pedal at any duration.



Who tried to change the natural application of power? In natural pedalling techniques effective torque application takes place between 1 and 5 o'c with a dead spot sector between 11-1 o'c. In all research that has taken place to date, there is still a dead spot sector and effective power application takes place between 1 and 5 o'c, how could there be any power improvement.
 
Mar 10, 2009
965
0
0
Visit site
JayKosta said:
-----------
I basically agree with your 'half-stroke' method.

If high power is produced for a full 180 degrees of crank rotation, then I think there is some amount of positive force being produced prior to the 0 degree point, and after the 180 degree point - even though there isn't any concentration on producing high power at those points.

Extending the high power to full half-stroke reduces the ineffective portion from two thirds to near the one third portion where the other leg is doing its 'conventional power application'.

Jay Kosta
Endwell NY USA



There is some slight force after 5 o'c following the simultaneous switch over of power application from one leg to the other, instead of following through with the downward power towards 6, the leg muscles instantly go into reverse mode at 5 as the foot is unweighted and drawn back but it is mainly only clearing a resistance free path for the idling pedal. There is no additional force before 11, torque goes instantly from zero to 2 o'c equivalent. The ineffective portion of the circle is a half (5-11) which the muscles use for recovery between power strokes. I don't understand how you get reduction to a third, you can only give total concentration to each leg over 180 deg.
 
coapman said:
There is some slight force after 5 o'c following the simultaneous switch over of power application from one leg to the other, instead of following through with the downward power towards 6, the leg muscles instantly go into reverse mode at 5 as the foot is unweighted and drawn back but it is mainly only clearing a resistance free path for the idling pedal. There is no additional force before 11, torque goes instantly from zero to 2 o'c equivalent. The ineffective portion of the circle is a half (5-11) which the muscles use for recovery between power strokes. I don't understand how you get reduction to a third, you can only give total concentration to each leg over 180 deg.
--------------------------
1) From 5 to 11, is the pedal consciously being
"unweighted and drawn back but it is mainly only clearing a resistance free path for the idling pedal"?
If the 5-11 movement is not done with some amount of conscious control, how do you ensure that it is being done effectively?

2) At 11, I really doubt that
"torque goes instantly from zero to 2 o'c equivalent".
I suspect there is a pre-11 buildup of force that begins earlier - perhaps at 10.
And as you said
"There is some slight force after 5 o'c following the simultaneous switch over of power application from one leg to the other".

Jay Kosta
Endwell NY USA
 

TRENDING THREADS