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The pedaling technique thread

Moderator: King Boonen

11 Oct 2018 04:42

blah blah blah.

Data please Noel. All else is meaningless twaddle.
User avatar Alex Simmons/RST
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Re:

12 Oct 2018 22:31

Alex Simmons/RST wrote:blah blah blah.

Data please Noel. All else is meaningless twaddle.


If Jim used his work loop modeling on this example (below) of how the glutes and quads (together with the lower leg muscles) can be used to generate maximal crank torque at TDC and beyond, you would have your data.

"All Jim has to do in his lab is sit in an office chair fitted with casters, without arm rests, then pressing down with his hands on the front portion of the sides of the seat, with heel raised on a non slip surface, force that chair backwards (single leg action. That is the basic technique and it's when this forward force is applied to a fast moving pedal that you get the perfect high gear TT technique. It will demonstrate how the powerful calf muscles, ankle and plantar flexion can be put to work in pedalling around TDC, and is very different from the kicking action recommended by the experts. As for bike set-up, the bars need to be in a position that would leave your arm resistance line roughly parallel to that forward force application line between 1 and 1.30 when in the drops position. On my trainer bike I use cut down and rejoined normal bars instead of the Scott Rake aero bars. A model for the work loop tool."
backdoor
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Re: Re:

12 Oct 2018 23:27

Alternatively, if you would read the paper you would understand that the muscles are already doing everything that can be done to produce power. Where shall I send it so you can read rather than speculate?
Of course, if your real purpose is to troll rather than to learn or even debate then troll on.

backdoor wrote: If Jim used his work loop modeling on this example (below) of how the glutes and quads (together with the lower leg muscles) can be used to generate maximal crank torque at TDC and beyond, you would have your data.
PhitBoy
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Re: Re:

13 Oct 2018 19:20

PhitBoy wrote:Alternatively, if you would read the paper you would understand that the muscles are already doing everything that can be done to produce power. Where shall I send it so you can read rather than speculate?
Of course, if your real purpose is to troll rather than to learn or even debate then troll on.

backdoor wrote: If Jim used his work loop modeling on this example (below) of how the glutes and quads (together with the lower leg muscles) can be used to generate maximal crank torque at TDC and beyond, you would have your data.


I did send a PM but obviously you did not receive it. My e-mail address is ncrowley98@gmail.com
backdoor
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Re: Re:

15 Oct 2018 23:27

PhitBoy wrote:Alternatively, if you would read the paper you would understand that the muscles are already doing everything that can be done to produce power. Where shall I send it so you can read rather than speculate?
Of course, if your real purpose is to troll rather than to learn or even debate then troll on.



Thanks for the paper, it was too complicated for me to fully understand. You were correct in that earlier post,
but you did not mention it was high cadence sprinting that was involved in the study. This meant you would be restricted by time per crank revolution in the muscles and technique that could be used.
"We maximized the power that every muscle produced throughout the pedal cycle and came up with patterns that look almost identical to what cyclists do. That means there is nothing else the muscles can do to produce power in some other technique. Any other technique will be less powerful, not more. The differences we saw at the ankle occur during the middle of the recovery portion of the cycle where an active ankle extension would be counter productive. That is, even though soleus could produce more power during that portion of the cycle, doing so would produce negative power on the crank."
backdoor
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Re: Re:

02 Nov 2018 00:31

backdoor
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Re: Re:

14 Nov 2018 19:58

Got to hand it to you Noel, you never give up.
This one seemed really promising for your side and perplexing to me initially. I know Dr. Ettema and he's a solid scientist who trained under Sjøgaard. The issue with this study finally came to me when I was reading the discussion and he was talking about conservation of kinetic energy. "From a power balance standpoint, the athlete does not fully maintain the amount of external kinetic energy (i.e., energy related to the velocity relative to the environment) by generating the same power that is lost due to external resistance."
While this is true the effect is minuscule in a moving bike and in a stationary bike with a high inertia flywheel. So that got me to looking more carefully at the methods. They used a Tacx; I-Magic trainer with a small flywheel. So yes, if you are on a trainer with little or no kinetic energy storage the cranks will slow down at the deadspots. Thus, as their data indicate it might be beneficial to minimize the deadspot to keep the cranks moving somewhat fluidly. In fact, one wind trainer brand boasts that it has no momentum (kinetic energy) and that forces you to pedal through the deadspot.
But other studies with realistic kinetic energy show the opposite.
Keep trying!
Jim

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PhitBoy
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Re: Re:

16 Nov 2018 12:11

PhitBoy wrote:Got to hand it to you Noel, you never give up.
This one seemed really promising for your side and perplexing to me initially. I know Dr. Ettema and he's a solid scientist who trained under Sjøgaard. The issue with this study finally came to me when I was reading the discussion and he was talking about conservation of kinetic energy. "From a power balance standpoint, the athlete does not fully maintain the amount of external kinetic energy (i.e., energy related to the velocity relative to the environment) by generating the same power that is lost due to external resistance."
While this is true the effect is minuscule in a moving bike and in a stationary bike with a high inertia flywheel. So that got me to looking more carefully at the methods. They used a Tacx; I-Magic trainer with a small flywheel. So yes, if you are on a trainer with little or no kinetic energy storage the cranks will slow down at the deadspots. Thus, as their data indicate it might be beneficial to minimize the deadspot to keep the cranks moving somewhat fluidly. In fact, one wind trainer brand boasts that it has no momentum (kinetic energy) and that forces you to pedal through the deadspot.
But other studies with realistic kinetic energy show the opposite.
Keep trying!
Jim

Image




http://strongbyscience.net/2017/05/26/muscle-slack/
backdoor
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Re: Re:

Yesterday 07:26

PhitBoy wrote:So that got me to looking more carefully at the methods. They used a Tacx; I-Magic trainer with a small flywheel. So yes, if you are on a trainer with little or no kinetic energy storage the cranks will slow down at the deadspots.

Which is exactly what this study demonstrated, see figure 5 for charts plotting the typical crank velocity variation when using a trainer with low crank inertial load, in this case a CycleOps Powerbeam Pro trainer.

http://tinyurl.com/qapfoek

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User avatar Alex Simmons/RST
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