Pedal forces result from a combination of muscular forces and gravity and inertia forces. Most of the ineffective forces are due to gravity (eg the weight of the limb when the pedal is coming up). Those forces stay constant. The muscular forces that cyclists choose to produce are highly effective. So as power (and muscular force) increase, the ratio of effective to ineffective goes up.
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Noel is a "flat earther" of cycling. A true believer.
No amount of evidence, logic and sense are going to convince him. He worships upon the altar of Anquetil's mythical pedalling and such deep faith can't be reasoned with. Perhaps a visit from the ghost of Jacques crying out in a ghostly rhythm "just push harder Noel, just push harder... that is the secret", may just help.
If Anquetil had never existed I would still have discovered his technique, because I found it when I succeeded in biomechanically combining arm and leg power. For that you need to generate a powerful forward force and that simple chair racing technique was the solution.
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That would require a muscular force. Everyone does this to some extent. As mentioned months or years ago in this thread, all studies which investigate really pulling up show that it REDUCES efficiency / INCREASES metabolic cost. Even in a single legged cyclist, pulling up LESS is more efficient.
Alex is right. Not sure why I got sucked back in to this black hole of a thread. Maybe again in a year or two.
Bye bye Noel. Feel free to have the last word.
Jim
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There is a vast difference between 'unweighting' and 'pulling up' .
In seated pedalling pulling up decreases power at 3 o'c, unweighting increases it.
From Slowtwitch
" Fleck
Mar 11, 05 8:18
Post #9 of 24 (2926 views)
They have done research on top time trialists and what they found was that they were the ones that consistently applied the most force at 3:00 o'clock - period. They also found there was minimal "lifting" of the recovery leg. What was really happening was that these top time trialists were managing to get the recovery leg out of the way, the fastest and most effectively so the on-leg could apply the most power. It also gave the off leg a microsecond or so of recovery.
Fleck "
( as quickly as possible for best effect looks better than " , the fastest and most effectively")
In seated pedalling pulling up decreases power at 3 o'c, unweighting increases it.
From Slowtwitch
" Fleck
Mar 11, 05 8:18
Post #9 of 24 (2926 views)
They have done research on top time trialists and what they found was that they were the ones that consistently applied the most force at 3:00 o'clock - period. They also found there was minimal "lifting" of the recovery leg. What was really happening was that these top time trialists were managing to get the recovery leg out of the way, the fastest and most effectively so the on-leg could apply the most power. It also gave the off leg a microsecond or so of recovery.
Fleck "
( as quickly as possible for best effect looks better than " , the fastest and most effectively")
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https://www.sciencedirect.com/science/article/abs/pii/S0765159719300280
The findings from that study are in keeping with the explanation as to why oval shaped chainrings will not work. All of which confirms high power pedalling technique will only change when a conscious effort is made to do so with a clear objective in mind, which is to attempt to double the extent of the sector where greatest torque can be applied to crank.
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Had to change username from backdoor to frontdoor. Posts of yours I missed.
There is nothing hidden about Hinault's pedalling technique. He gave a detailed explanation of it in his book over 30 years ago. His pedalling around BDC was identical to Anquetil's, Quote, " Thigh movement is minimal. Only knee flexing allows the pedal to be pulled backward. This takes practice because it isn't a natural movement. " That draws the downward force inertia smoothly around BDC. About his upstroke he wrote " Just being able to keep the weight of the leg off the rising pedal is a definite improvement compared to rudimentary pedalling techniques." But it is at TDC that the all important difference between his and Anquetil's pedalling can be found. He wrote " Going through the upper dead spot . By extending the knee you can push the pedal forward." That is the same as using the powerless forward kicking action, while Anquetil used knee extension to steer his powerful driving hip force over TDC and downward towards 2 o'c. Anquetil also used the start of that knee flexing around BDC to boost resistance at the simultaneous switch over between legs of power application at 11 o' c.
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https://www.ncbi.nlm.nih.gov/pubmed/17414806 https://www.ncbi.nlm.nih.gov/pubmed/17414806
That was what I had figured out Alex as to why pedal force effectiveness is increased at higher power output and reduced at higher pedalling cadences.
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"Abstract
Cadence or pedal rate is widely accepted as an important factor influencing economy of motion, power output, perceived exertion and the development of fatigue during cycling. As a result, the cadence selected by cyclists could have a significant influence on their performance. Despite this, the cadence that optimises performance during an individual cycling task is currently unclear. The purpose of this review therefore was to examine the relevant literature surrounding cycling cadence in order provide a greater understanding of how different cadences might optimise cycling performance. Based on research to date, it would appear that relatively high pedal rates (100-120 rpm) improve sprint cycling performance, since muscle force and neuromuscular fatigue are reduced, and cycling power output maximised at such pedal rates. However, extremely high cadences increase the metabolic cost of cycling. Therefore prolonged cycling (i.e. road time trials) may benefit from a slightly reduced cadence (~90-100 rpm). During ultra-endurance cycling (i.e. >4h), performance might be improved through the use of a relatively low cadence (70-90 rpm), since lower cadences have been shown to improve cycling economy and lower energy demands. However, such low cadences are known to increase the pedal forces necessary to maintain a given power output. Future research is needed to examine the multitude of factors known to influence optimal cycling cadence (i.e. economy, power output and fatigue development) in order to confirm the range of cadences that are optimal during specific cycling tasks. "
How would you solve that problem, by making it possible to reduce cadence while maintaining a given power output without having to increase pedal force ?
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That was what made Anquetil's high gear pedalling more sustainable in flat time trials. You change to a higher gear and switch pedalling technique to one that extends the sector where greatest force and greatest tangential effect are used to include the 12 - 2 o'c sector. This means peak force does not have to be increased. You are reversing what occurs at the highest pedalling cadences by activating the strongest and most fatigue resistant muscles in the lower body around TDC and beyond. (see previous post). The lower body forward force generating technique used in chair racing is identical to that used in the powerful sport of indoor tug o'war, that's what makes arm resistance a vital part of this TT pedalling technique. For this reason saddle to bars setting has to be precise and would explain why Anquetil's bars were set higher than was customary for those years.
That video demonstrates the torque generating technique that can extend the most effective pedalling sector, it also demonstrates the foot draw back technique described by Hinault in his book. Only difference is , without an up and down stroke and arm resistance they are using a faster shortened and therefore much weaker version. It can be learned in a minute or two.
View: https://www.facebook.com/Vocativ/videos/301204007442681/
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https://pubmed.ncbi.nlm.nih.gov/313...nical-power-output-at-cadences-above-120-rpm/
If they had read that study above done 12 years earlier they would have realised it was due to deteriorating pedal force effectiveness (worsening crank torque return from the force) caused by a later start to the down force, the higher the cadence the later the start.
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https://www.sciencedirect.com/science/article/abs/pii/S0021929019308474
In that improved aerodynamic version of Anquetil's TT technique lies the only solution for the removal of all lower back stress which together with an imperfect lower back is the root cause of cycling's lower back pain. That continuous stress is caused by natural pedalling, in which peak torque has to be applied vertically downward at 3 o'c and almost all upper body weight has to be supported by the lower back when in that leaning forward position, in addition to any pulling on the bars. Changing peak torque application to around 1.30 means all that peak torque stress is absorbed by the hips. Combined arm/leg pedalling means arms are discreetly working alternately in unison with the legs, as one arm is supplying the necessary resistance for the change of peak torque to 1.30, the other arm is braced on the aero bar (Scott Rake} *in drops position, supporting all upper body weight and adding to the resistance of the other arm without any fatigue of the arms, leaving a completely stress free lower back. It also places less stress on the knees.
* I cut and rejoined normal bars for a 21 cm bar width to replicate the Scott Rake bars effect on trainer bike and put brake levers and hoods on it for use when creating the technique. The narrow bars hand positions eliminate side to side leverage.
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Physiological Response to Professional Road Cycling: Climbers vs. Time Trialists
Article in International Journal of Sports Medicine 21(7):505-12 · November 2000 with 424 Reads
Abstract
The purpose of this study was to identify possible physiological differences between professional cyclists who show best performance in hill climbing ("climbers") and those who excel in time trials ("time trialists"). To this end, professional, top-level climbers (C; n=8; age 26 +/- 1yr; height 176.0 +/- 2.0cm; body mass 63.6 +/- 2.2 kg) and time trialists (TT; n=6; 27 +/- 1yr; height 181.6 +/- 1.7 cm; body mass 72.3 +/- 2.3 kg) were required to perform two laboratory exercise tests on a cycle ergometer: a) a maximal exercise test (ramp protocol) and b) a constant load test of 20-min duration at approximately 80% of VO2max. Capillary blood lactate concentration and several gas exchange variables were measured during the maximal tests while determinations made during the submaximal tests also included: pH and bicarbonate concentration [HCO3-] in venous blood, and electromyographic (EMG) recordings from the vastus lateralis muscle to estimate root mean square voltage (rms-EMG) and mean power frequency (MPF). Both the maximal lactate concentration in capillary blood and VO2max were greater (p<0.05) in C than in TT (6.6 +/- 0.9 mM vs. 5.0 +/- 0.4 mM, respectively, and 78.4 +/- 3.2 ml x kg(-1) x min(-1) vs. 70.5 +/- 2.4 ml x kg(-1) x min(-1), respectively). Higher mean venous blood pH and [HCO3-] (p<0.05), rms-EMG (p<0.01) and MPF (p<0.05 at 10 and 15min of exercise and p < 0.01 at 5 and 20 min) were recorded in C throughout the submaximal tests. Our findings suggest that in top-level professional cyclists, climbing performance is mainly related to physiological factors (VO2max normalized for body mass, anaerobicl buffer capacity, motor unit recruitment) whereas time trialists tend to achieve greater absolute power outputs. It would also seem that other "technical" requirements of the sport (i. e. pedaling efficiency probably related to biomechanical factors etc.) may be associated with successful time trial performance.
That second 'chair racing' video above should answer both those questions. The perfected forward pedal force generating technique is for use between 11 and 2 o'c, where merging with natural downward force takes place. Start by using the technique at 1 o'c, perfecting means attempting to apply this torque earlier and earlier until you can get a simultaneous switch over of power application from one leg to the other. You are then getting extra pedalling time by being able to apply close to maximal torque where all other pedalling styles are effectively idling and in addition a much better torque return from the force you are applying because of increased pedalling effectiveness.
"Mastering a bicycle to produce maximum power output, as elite cyclists must, is also a balancing act between the two types of muscle fibres: slow-twitch (Type I) muscle fibres and fast-twitch (Type II) muscle fibres.
Slow-twitch fibres contract slowly, can be used for longer periods of time – ideal for endurance athletes – and rely on oxygen as their main energy source.
Fast-twitch fibres contract quickly, provide strength and speed – ideal for sprinting – and fatigue more quickly than slow-twitch fibres.
The distribution of these fibres varies between the muscles of different cyclists. We know that the Rectus Femoris (pictured) - one of the four quadricep muscles in the thigh - has a high percentage of fast-twitch muscle fibres while the Soleus – around the calf muscles - has a high percentage of slow-twitch muscle fibres."
In flat time trials when necessary Anquetil knew how to get maximal torque from the soleus at 12 and 1 o'c for the ideal balance between fast and slow-twitch muscle fibres, all other cyclists use it for minimal torque (if any) in their downstroke, and the lower and more aero he got, the more powerful his pedalling.
https://www.gettyimages.ie/detail/news-photo/roger-rivière-encourangeant-jacques-anquetil-pendant-la-news-photo/1053041386?adppopup=true
"The muscle groups in your calves, ankles and feet don’t contribute as much to your power as you might think, says physiotherapist Phil Burt, who has supported Britain’s elite cyclists at three Olympic games and Team Sky at seven Tours de France.
He cites Paralympic cyclists who have lost their lower legs and are actually more efficient cyclists"
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Sample size of 8 riders?! Come on, if those folks are going to bother doing a study they need to recruit more subjects.
https://www.researchgate.net/publication/338576198_Strategies_for_improving_the_pedaling_technique
What I find surprising is nobody has ever raised the question as to why the unweighting technique has never been included in pedalling studies. One explanation can be found in your reply above in post 2155, which is, scientists who have carried out these studies don't know the difference between pulling up and unweighting.
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They should have read the studies carried out on F. Day's POWERCRANKS before starting this study.
https://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=9050412 .
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https://www.cyclinguk.org/cycle-magazine/pedalling-dynamics
The last few sentences plus the reference to unweighting are the important lines in that article. There is no one technique suitable for all the requirements of competitive cycling, but for flat nontechnical TT's the ideal technique lies in making maximal use of the soleus with its high percentage of slow-twitch fibers around TDC and beyond and doubling that small segment where maximal tangential force can be applied by starting that special powerful forward force application at 11 and using the Hinault draw back technique at 5. This increases power application, increases pedalling effectiveness and also cuts back on wasted energy.
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Not that this will sway any of the true believers but we think this is the final nail in the coffin of pedaling technique lore: https://journals.physiology.org/doi/abs/10.1152/japplphysiol.00661.2020
The amazingly cool thing is that this amputee cyclist's metabolic cost decreased with the counterweight by exactly the same amount as the increase reported in other studies in which cyclists were instructed to pull up.
The message is: Just pedal and don't worry about it.
Metabolic Power and Efficiency for an Amputee Cyclist: Implications for Cycling Technique
Steven J. Elmer * and James C. Martin
24 Dec 2020https://doi.org/10.1152/japplphysiol.00661.2020
Abstract
Cycling technique is steeped in cultural lore. One deeply held belief is that "pulling-up" to lift the leg (increased muscular leg flexion) will optimize technique and improve efficiency. In contrast, scientific evidence suggests that when cyclists are instructed to pull-up efficiency decreases. However, such interventions may not have allowed sufficient time for cyclists to adapt and refine their technique. This case study documented how a cyclist with a complete unilateral limb amputation consumed metabolic power to produce mechanical power during single-leg cycling. The cyclist was a 4-time U.S. National Paralympic Champion who performed single-leg cycling for 7yrs and thus was fully adapted to pull-up. We hypothesized that a counterweight system, which reduced the requirement to pull-up, would decrease metabolic power and increase efficiency for this cyclist. The cyclist performed submaximal cycling (100, 135, 170, 205W, 80rpm, 5min) with and without a counterweight (10kg) on the unused crank. Expired gasses were measured, and metabolic power and gross efficiency were calculated. Metabolic power decreased on average by 87±7W (p<0.001) and gross efficiency increased from 16.3±1.9 to 18.0±1.8% (p<0.001) when cycling with the counterweight. During counterweighted single-leg cycling, the metabolic power of unloaded cycling decreased (317 vs. 238W) and delta efficiency was similar (25.2 vs. 25.5%). Results demonstrated that significant metabolic power was associated with pulling-up to produce muscular leg flexion power even in a cyclist who pulled-up substantially during cycling. Our findings confirm observations from previous studies that altered pedaling technique acutely and indicate that pulling-up during cycling is less efficient.
The amazingly cool thing is that this amputee cyclist's metabolic cost decreased with the counterweight by exactly the same amount as the increase reported in other studies in which cyclists were instructed to pull up.
The message is: Just pedal and don't worry about it.
Metabolic Power and Efficiency for an Amputee Cyclist: Implications for Cycling Technique
Steven J. Elmer * and James C. Martin
24 Dec 2020https://doi.org/10.1152/japplphysiol.00661.2020
Abstract
Cycling technique is steeped in cultural lore. One deeply held belief is that "pulling-up" to lift the leg (increased muscular leg flexion) will optimize technique and improve efficiency. In contrast, scientific evidence suggests that when cyclists are instructed to pull-up efficiency decreases. However, such interventions may not have allowed sufficient time for cyclists to adapt and refine their technique. This case study documented how a cyclist with a complete unilateral limb amputation consumed metabolic power to produce mechanical power during single-leg cycling. The cyclist was a 4-time U.S. National Paralympic Champion who performed single-leg cycling for 7yrs and thus was fully adapted to pull-up. We hypothesized that a counterweight system, which reduced the requirement to pull-up, would decrease metabolic power and increase efficiency for this cyclist. The cyclist performed submaximal cycling (100, 135, 170, 205W, 80rpm, 5min) with and without a counterweight (10kg) on the unused crank. Expired gasses were measured, and metabolic power and gross efficiency were calculated. Metabolic power decreased on average by 87±7W (p<0.001) and gross efficiency increased from 16.3±1.9 to 18.0±1.8% (p<0.001) when cycling with the counterweight. During counterweighted single-leg cycling, the metabolic power of unloaded cycling decreased (317 vs. 238W) and delta efficiency was similar (25.2 vs. 25.5%). Results demonstrated that significant metabolic power was associated with pulling-up to produce muscular leg flexion power even in a cyclist who pulled-up substantially during cycling. Our findings confirm observations from previous studies that altered pedaling technique acutely and indicate that pulling-up during cycling is less efficient.
Did the cyclist use the counter weight to 'push' the pedaling leg up, or was it more a matter of 'unweighting' the pedaling leg on the up-stroke (a low effort 'just keep the leg moving' action).
The counterweight reduces the effort required to lift the leg. Cyclists do pull up a little bit with the counterweight just like most people do when pedaling normally with both legs. So the latter of your two scenarios.
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