For the "pedaling technique doesn't matter crowd"

[FrankDay]

You will be discussing it.

No, you will be chiming in also (even though few would consider your input actually discussing, which usually involves a back and forth exchange of ideas) because you can't control yourself about this topic.

 

[CoachFergie]

Can't control my amusement on the numerous claims you make.

 

[Boeing]

same coachfungi. lots of criticism. no answers

 

[coapman]

This new study should come close to doing the trick (what concerns me some is I don't believe the PC use is exclusive so I am not sure this will be enough stimulus to definitively make the changes necessary). We will see.

You can't lose in this study, if results are negative for PC's, you already have an answer even before it starts. I could teach a rider to unweight the pedals in a day, all that's required is a cheap pair of platform pedals. How many forces does the unweighter have to deal with.

 

[FrankDay]

I could teach a rider to unweight the pedals in a day

Good for you. Prove it.

 

[coapman]

1) With PC, the rider's leg is always 'working' - except for a brief moment at about 315 degrees.

What makes you think the leg is not working for a brief moment at about 315 deg. ?

 

[FrankDay]

What makes you think the leg is not working for a brief moment at about 315 deg. ?

Are you capable of interpreting graphs? What do you think is going on at about 315º? While I agree that the term "not working" may require discussion when potential energy is included in the discussion somehow I don't think your question is so nuanced. Could you be more clear as to what you meant?

 

[FrankDay]

A 'good test' of PC should include: power output, torque graph, oxygen usage, and pulse rate on non-PC BEFORE the start of PC training.
The test subjects should be strong active cyclists who have stopped improving (so the benefit of PC training is the only additional factor).

I would disagree that a good test would require the participants to be strong active cyclists who have stopped improving. The problem with studies involves recruiting subjects. It would be extremely difficult to recruit a large number of strong active cyclists who have stopped improving to forgo normal training for a long period to participate in a study. (I think that is what Dixon did, check out his results, but no one believes his data) A good test only requires a matched control group whereby the only discernible difference between the groups is the PC training. In a great study the included cyclists would be strong active cyclists who have stopped improving and then randomly placed into a PC or control group. Will that ever occur? Perhaps. But probably not until that good study is done. BTW, I think the proposed study that reanimated this discussion is coming close to meeting your criteria (although I will have to wait to see the actual protocol until I determine how close it comes to meeting my ideal design).

 

[coapman]

Are you capable of interpreting graphs? What do you think is going on at about 315º?

I think the muscles are working equally as hard if not harder but getting less return in positive torque for the effort.

 

[FrankDay]

I think the muscles are working equally as hard if not harder but getting less return in positive torque for the effort.

equally hard as what?

 

[coapman]

equally hard as what?

Equally as hard as from 7 to 10 o'c.

 

[FrankDay]

Equally as hard as from 7 to 10 o'c.

And, do you have any thoughts comparing the blue to the green from 7 to 10 as to what the muscles are doing or not doing and which would be better or worse?

 

[FrankDay]

Just found out about a study ([url=http://sportsexerciseengineering.com/2012/08/14/study-of-the-pedal-stroke-force-magnitude-and-force-direction-changes-due-to-power-crank-use-over-traditional-connected-cranks/]http://sportsexerciseengineering.com/20 ... ed-cranks/)[/url] that is scheduled to start soon that might get us talking about this topic again. I am not sure of the details of the design but it is going to last 6 months and look at any changes in the pedaling dynamic that occurs as a result of this training and whether there is also any change in VO2max and efficiency that corresponds compared to a control group.

I just found out more information regarding this study which makes me even more excited. There are 8 riders in the study, 4 will be in the PC group and 4 in the "connected cranks" group. There are 2 matched cat 4, cat 3, cat 2, and cat 1 riders so there will be the ability to compare the potential in those "not so good" to the "very good". Further, the subjects will be required to complete 6 hrs training of zone 2 or above on a weekly basis for the six months. TOTAL HRS 156 PER RIDER IN BOTH GROUPS so 624hrs for the PC group and 624hrs for the CC group. These hrs will be as part of their own winter training program. I think this compares well to the 10 hours over 6 weeks in some other "negative" studies.

While the number of subjects is small I think the stimulus and length of time the study will last should be able to make some positive determinations. We will see. Stay tuned.

 

[coapman]

And, do you have any thoughts comparing the blue to the green from 7 to 10 as to what the muscles are doing or not doing and which would be better or worse?

To apply effective torque you need resistance to counter act this force, what supplies the resistance for this torque between 7 and 10 o'c

 

[FrankDay]

To apply effective torque you need resistance to counter act this force, what supplies the resistance for this torque between 7 and 10 o'c

Really, did you just ask this question? The answer is the same thing that supplies the resistance when riding regular cranks. The road, through the wheel, then the chain.

 

[JayKosta]

There is probably a terminology confusion trying to use 'clockface' references - it makes a BIG difference whether the left or right crank is being considered...

Easiest to use degrees:
0 degree is with pedal at its highest point
45 degrees is 1/8 of a rotation (pushing downward)
90 degrees is 1/4 rotation (pushing downward)
135 ...
180 is 1/2 rotation with pedal at its lowest point
225 ... (pedal coming back up)
270 is 3/4 rotation
315 is 7/8 rotation
360 is full rotation with pedal again at its high point

Jay Kosta
Endwell NY USA

 

[coapman]

Really, did you just ask this question? The answer is the same thing that supplies the resistance when riding regular cranks. The road, through the wheel, then the chain.

I was referring to resistance behind the force you are applying to the pedal, body weight supplies resistance for the powerful downstroke. What supplies resistance for upstroke crank torque.

 

[FrankDay]

I was referring to resistance behind the force you are applying to the pedal, body weight supplies resistance for the powerful downstroke. What supplies resistance for upstroke crank torque.

In school the course you would take to learn how to solve these problems is called, as I recall, Statics (the prerequisite, as I recall, to mechanics - where dynamic problems are solved). Anyhow, to answer your question, the force to counter the increased "lifting" done by the recovery leg, as most PowerCrankers will tell you, is borne by the bicycle seat. This increase in magnified by the fact the rider is also pushing less with the other leg, which also increases the force on the seat. This analysis is assuming the force on the handlebars doesn't change.

 

[coapman]

Anyhow, to answer your question, the force to counter the increased "lifting" done by the recovery leg, as most PowerCrankers will tell you, is borne by the bicycle seat. This increase in magnified by the fact the rider is also pushing less with the other leg, which also increases the force on the seat. This analysis is assuming the force on the handlebars doesn't change.

Are you referring to the rider who was producing a steady 250 watts or to a cyclist who is riding at constant close to max power output in a TT.

 

[FrankDay]

Are you referring to the rider who was producing a steady 250 watts or to a cyclist who is riding at constant close to max power output in a TT.

High wattage, low wattage, zero wattage, it doesn't matter. The rider does not move in relation to the bike. Therefore, since there is no relative acceleration in relation to the bike the total forces have to add up to zero since F=ma. If someone is pushing down harder it simply means the force on the seat or handlebar goes down. If they pull up harder it means the force on the seat goes up. But, whatever happens, the totality of the forces on the rider add up to zero.

 

[coapman]

Anyhow, to answer your question, the force to counter the increased "lifting" done by the recovery leg, as most PowerCrankers will tell you, is borne by the bicycle seat. This increase in magnified by the fact the rider is also pushing less with the other leg, which also increases the force on the seat. This analysis is assuming the force on the handlebars doesn't change.

The important sentence in the above is ' This increase is magnified by the fact the rider is also pushing less with the other leg, which also increases force on the seat'. This confirms my claim that the more you pull up for almost minimal additional torque, the less you are pushing down with the other leg, resulting in an overall loss of crank torque.

 

[FrankDay]

The important sentence in the above is ' This increase is magnified by the fact the rider is also pushing less with the other leg, which also increases force on the seat'. This confirms my claim that the more you pull up for almost minimal additional torque, the less you are pushing down with the other leg, resulting in an overall loss of crank torque.

That statement confirms nothing. The fact that people tend to push less as they are learning to pull up (it helps them keep the cadence under control because unweighting at high cadences is REALLY HARD on these under trained muscles) does not mean they cannot push hard, once better trained, when push come to shove, so to speak. If one keeps the power and the cadence the same the amount one pushes less on the down stroke will exactly balance the amount they pull up more because the math dictates it to be so. Me thinks this soon to be done study that revived this thread will demonstrate this better than my words on the subject. Why don't you wait to see what it shows. Or, as an alternative, make your predictions now. Show everyone how smart you are and how well you understand this product by predicting the outcome. This goes for you too, Fergie (and some others).

 

[coapman]

That statement confirms nothing. The fact that people tend to push less as they are learning to pull up (it helps them keep the cadence under control because unweighting at high cadences is REALLY HARD on these under trained muscles) .

There is no difficulty in unweighting at high cadence, it's the pulling up that is really hard and not worth the effort for the minimal torque you get in return.

 

[JayKosta]

There is no difficulty in unweighting at high cadence, it's the pulling up that is really hard and not worth the effort for the minimal torque you get in return.

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I think the question of 'minimal torgue' of the pull-up is the BIG unknown about PCs.
Since doing the pull-up uses different (additional) muscles, the question is whether those muscles can be trained and developed to produce worthwhile extra torque.
Typically, using more muscles to produce power results in increased total power.
But, from a physiology viewpoint, a concern is how efficient are the pull-up muscles? If they are inefficient then the fuel (Calories) they burn will lessen the amount of fuel for the push-down muscles, and provide less total power output over a long period when available fuel become low.

Jay Kosta
Endwell NY USA

 

[FrankDay]

There is no difficulty in unweighting at high cadence…

LOL. You do realize that unweighting involves getting the foot up to pedal speed before unweighting can occur. Since high cadence means that pedal speed is higher and the time to get accelerate the foot from minimal upspeed (BDC, 189º) to maximum upspeed (9 oclock, 270º) goes is smaller, meaning the acceleration is increased. If cadence doubles the speed doubles and the time halves which means the necessary acceleration goes up by 4. Since F=ma I look forward to hearing again why people should have no difficulty unweighting at high cadences.