so what about cadence

[FrankDay]

That is true, but it's where in the pedaling circle one can start highly effective torque application that separates the value of different pedaling techniques on the ideal flat TT course. Where does your technique begin its highly effective torque application..

I guess one needs to define highly effective torque application before one can answer that question. I define "highly effective torque application" as being the applied force due to muscular contraction is tangential to the pedaling circle where the force is being applied. The closer the applied force is to tangential the more resultant torque results from that force.

I would like to think that I generate a highly effective torque application pretty much around the entire circle, all that varies being the size of the torque because the size of the forces vary so much due to the effects of gravity. I don't have proof per se (yet) but I am able to ride a Computrainer with spinscan numbers between 95-98, almost perfectly smooth.

 

[coapman]

I guess one needs to define highly effective torque application before one can answer that question.

I mean the equivalent of a masher's torque between 1.30 and 2 o'c. I am referring to torque, not tangential effect of the applied force.

 

[sciguy]

I am able to ride a Computrainer with spinscan numbers between 95-98, almost perfectly smooth.

Have you left instructions to have that engraved on your tombstone? It would seem to be a fitting portion of your epitaph

Hugh

 

[FrankDay]

I mean the equivalent of a masher's torque between 1.30 and 2 o'c. I am referring to torque, not tangential effect of the applied force.

If you define "effective torque" as the highest torque then the mashers will win. However, the highest torques do not correlate with the fastest times nor, even, the most power. In the linked study the two riders with the highest peak torques were only the 4th and 10th fastest of the 15 studied (see figure 4). The rider with the fastest TT in this group by far (51 min) had the highest power (figure 2) but only had the 4th highest peak torque and unweighted for a substantial portion of the backstroke (again see figure 4). There is more to effective application of torque than simply how hard one can push for a short period of time during the entire stroke. I like my definition better.

 

[coapman]

There is more to effective application of torque than simply how hard one can push for a short period of time during the entire stroke. I like my definition better.

Of course there is, that's why different techniques are needed for the various requirements that arise in competitive cycling and for flat TT's semi circular is the ideal style because it extends that 2-4 o'c close to maximal torque production sector from 60 deg. to 150 deg, which means your chain ring is getting 300 deg of close to maximal chain drive power over each revolution instead of the masher's or circular pedaler's 120 deg.

 

[coapman]

I don't have proof per se (yet) but I am able to ride a Computrainer with spinscan numbers between 95-98, almost perfectly smooth.

How does your 98 spinscan number pedaling technique compare with the pedaling technique and peak forces you have used in time trials.

 

[FrankDay]

How does your 98 spinscan number pedaling technique compare with the pedaling technique and peak forces you have used in time trials.

When doing a TT on the Veloton/Computrainer my spinscan number is typically 90+ except during periods of acceleration or changing power. It has been awhile since I have done one of these but I suspect not much has changed (or, perhaps, it has improved since I have changed to shorter cranks). I should be doing some more of this work soon when I get the iCranks software up and working and use the Velotron spinscan as a tool for comparing.

 

[coapman]

When doing a TT on the Veloton/Computrainer my spinscan number is typically 90+ except during periods of acceleration or changing power. It has been awhile since I have done one of these but I suspect not much has changed (or, perhaps, it has improved since I have changed to shorter cranks). I should be doing some more of this work soon when I get the iCranks software up and working and use the Velotron spinscan as a tool for comparing.

What I mean is, how does the spinscan technique compare with the technique you used on outdoor road 10 mile TT's before the computrainer arrived on the scene. How does your torque application compare around the 3 o'c mark.

 

[FrankDay]

What I mean is, how does the spinscan technique compare with the technique you used on outdoor road 10 mile TT's before the computrainer arrived on the scene. How does your torque application compare around the 3 o'c mark.

Before CT I rode pretty much like everyone else with a spinscan number in the 70's. I haven't used the CT to change my pedaling technique but these changes have occurred because of my training with PowerCranks. My current "spinscan technique" is my time trial technique as I am simply riding my bike. Regarding torque at 3 o'clock, apparently you don't understand what the spinscan is. The spinscan number is nothing more than the average total torque divided by the peak total torque (when both cranks are added together). Spinscan doesn't look at the torque at 3 but instead adds the torque at 9 on the left to the torque at 3 on the right and then puts that out as the torque on the right. (this is reasonable because the torque at 9 is typically very small compared to the pushing torque). So, the circle the spinscan displays is actually two half circles put together. And, the spinscan number is nothing more than the average torque for a single revolution divided by the max torque on that revolution times 100. This means that if the spinscan number is 100 the average torque equals the max torque so the combined torque at 3 is the same as the combined torque at 12 or anywhere else on the circle. What does that mean for the individual torques. If we assume that the legs are balanced and that the torque at 9 is zero then the torque at 3 will be twice what it is at 6 and 12 (the two pedals have to add up to the same amount everywhere if the spinscan is 100).

A Spinscan of 95 means the combined torque at 3 (probably the highest torque) is just marginally higher than the combined torque at other areas of the circle.

 

[sciguy]

What I mean is, how does the spinscan technique compare with the technique you used on outdoor road 10 mile TT's before the computrainer arrived on the scene. How does your torque application compare around the 3 o'c mark.

Frank does not compete is such events perhaps finding it more gratifying the "imagine" competing in them. I've teased him for years that he needs to actually get out there and compete if he really wants to intimately understand cycling performance. I was excited to hear he considered entering an Ironman Triathlon but guess he thought better of the idea. He'd likely crush the dreams of all those septuagenarians not using 130mm cranks


Hugh

 

[CoachFergie]

He is not the only one here that would be crushed if he actually went out and got some real world data.

To the OP, what about cadence, nothing of significance really.

 

[coapman]

Before CT I rode pretty much like everyone else with a spinscan number in the 70's. I haven't used the CT to change my pedaling technique but these changes have occurred because of my training with PowerCranks. My current "spinscan technique" is my time trial technique as I am simply riding my bike. Regarding torque at 3 o'clock, apparently you don't understand what the spinscan is. The spinscan number is nothing more than the average total torque divided by the peak total torque (when both cranks are added together). Spinscan doesn't look at the torque at 3 but instead adds the torque at 9 on the left to the torque at 3 on the right and then puts that out as the torque on the right. (this is reasonable because the torque at 9 is typically very small compared to the pushing torque). So, the circle the spinscan displays is actually two half circles put together. And, the spinscan number is nothing more than the average torque for a single revolution divided by the max torque on that revolution times 100. This means that if the spinscan number is 100 the average torque equals the max torque so the combined torque at 3 is the same as the combined torque at 12 or anywhere else on the circle. What does that mean for the individual torques. If we assume that the legs are balanced and that the torque at 9 is zero then the torque at 3 will be twice what it is at 6 and 12 (the two pedals have to add up to the same amount everywhere if the spinscan is 100).

A Spinscan of 95 means the combined torque at 3 (probably the highest torque) is just marginally higher than the combined torque at other areas of the circle.

Where is the advantage in having your torque at 3/9 o'c reduced to what can be applied at 12/6 o'c. The difference between your smooth technique and mine appears to be, I am applying smooth maximal torque, you are applying smooth minimal torque.

 

[FrankDay]

Where is the advantage in having your torque at 3/9 o'c reduced to what can be applied at 12/6 o'c. The difference between your smooth technique and mine appears to be, I am applying smooth maximal torque, you are applying smooth minimal torque.

I am developing that smooth torque by increasing the torque at the top and the bottom not by reducing the pushing torque. You, on the other hand, have provided us no actual evidence that you are actually pedaling smoothly or pedal in the manner you say you do. In fact, I think it is almost a certainty that you are not pedaling as you think you do. When you ride computrainer, what is your spinscan number? What does your spinscan look like?

 

[Dear Wiggo]

Before CT I rode pretty much like everyone else with a spinscan number in the 70's. I haven't used the CT to change my pedaling technique but these changes have occurred because of my training with PowerCranks. My current "spinscan technique" is my time trial technique as I am simply riding my bike. Regarding torque at 3 o'clock, apparently you don't understand what the spinscan is. The spinscan number is nothing more than the average total torque divided by the peak total torque (when both cranks are added together). Spinscan doesn't look at the torque at 3 but instead adds the torque at 9 on the left to the torque at 3 on the right and then puts that out as the torque on the right. (this is reasonable because the torque at 9 is typically very small compared to the pushing torque). So, the circle the spinscan displays is actually two half circles put together. And, the spinscan number is nothing more than the average torque for a single revolution divided by the max torque on that revolution times 100. This means that if the spinscan number is 100 the average torque equals the max torque so the combined torque at 3 is the same as the combined torque at 12 or anywhere else on the circle. What does that mean for the individual torques. If we assume that the legs are balanced and that the torque at 9 is zero then the torque at 3 will be twice what it is at 6 and 12 (the two pedals have to add up to the same amount everywhere if the spinscan is 100).

A Spinscan of 95 means the combined torque at 3 (probably the highest torque) is just marginally higher than the combined torque at other areas of the circle.

Does your spin scan score get averaged over a 3 hour ride? If no, can you tell us the duration for that score of 95?
What power are you producing with that score?
Is your power with that score different to what it was when you started off, and were hitting 70s?

Cheers!

 

[FrankDay]

Does your spin scan score get averaged over a 3 hour ride?

No

If no, can you tell us the duration for that score of 95?

Many minutes. In general most of the rides in which I have done this is at expo's showing people what is possible to compare with what they just did. I made a video of my doing this but I can't seem to find it now.

What power are you producing with that score?

In the 2-300 watt range.

Is your power with that score different to what it was when you started off, and were hitting 70s?

Yes. I did a Conconi test before I started training with PowerCranks and had a max of 280 watts (a test performed on me by John Howard at a tri camp). This was when I pedaled like everyone else. I repeated the test after I was well adapted to PowerCranks and reached a max of 360 watts as I remember. It was a few years later when I was even better adapted that I went back just to see what my spinscan looked like and I certainly had not regressed. I will try to find those videos. Correction: Conconi scores were 260W and 380W.

 

[coapman]

I am developing that smooth torque by increasing the torque at the top and the bottom not by reducing the pushing torque. You, on the other hand, have provided us no actual evidence that you are actually pedaling smoothly or pedal in the manner you say you do. In fact, I think it is almost a certainty that you are not pedaling as you think you do. When you ride computrainer, what is your spinscan number? What does your spinscan look like?

Impossible, as your cadence increases you would soon lose your ability to apply this torque at 12/6 because at a cadence of 90 you would have to make twelve adjustments per second to your pedaling. I have supplied no evidence but by using another sport I have explained exactly how my muscles apply maximal torque at 12 o'c and at a cadence of 120, it only needs four adjustments per second.

 

[FrankDay]

Impossible, as your cadence increases you would soon lose your ability to apply this torque at 12/6 because at a cadence of 90 you would have to make twelve adjustments per second to your pedaling. I have supplied no evidence but by using another sport I have explained exactly how my muscles apply maximal torque at 12 o'c and at a cadence of 120, it only needs four adjustments per second.

I suspect I am making many more adjustments per second than 12 as do most people. Most people are constantly changing the direction of the applied force to the pedals. Happens without thinking about it. One of the wonders of having a cerebellum and spinal cord when doing a learned repetitive motion.

 

[coapman]

Happens without thinking about it.

Yes in your dreams.

 

[Dear Wiggo]

NoMany minutes. In general most of the rides in which I have done this is at expo's showing people what is possible to compare with what they just did. I made a video of my doing this but I can't seem to find it now.In the 2-300 watt range.Yes. I did a Conconi test before I started training with PowerCranks and had a max of 280 watts (a test performed on me by John Howard at a tri camp). This was when I pedaled like everyone else. I repeated the test after I was well adapted to PowerCranks and reached a max of 360 watts as I remember. It was a few years later when I was even better adapted that I went back just to see what my spinscan looked like and I certainly had not regressed. I will try to find those videos. Correction: Conconi scores were 260W and 380W.

I presume you mean a step test to exhaustion?

Do you remember the protocol? ie step duration and power increase?

It would be interesting if it was something you had sustained for a useful length of time - many minutes doesn't sound very accurate nor useful for anything beyond demonstration.

 

[FrankDay]

I presume you mean a step test to exhaustion?

Yes

Do you remember the protocol? ie step duration and power increase?

I believe we started about 150 watts then went up 20 watts every 2 minutes, as I remember

It would be interesting if it was something you had sustained for a useful length of time - many minutes doesn't sound very accurate nor useful for anything beyond demonstration.

I am not aware that peoples pedaling technique varies substantially over time. Of course it will change some but is it significant? I suspect my technique looks pretty much the same after 2 hours as it does after 2 minutes. I certainly don't revert to my pre PC style since it is impossible since I am on PC's.

I expect to be doing an IM bike leg at the end of June. Hopefully I will have the ability to record my pedaling style during the ride so I will be able to document how much and how I change during a 6 hr or so ride.

 

[Dear Wiggo]

I expect to be doing an IM bike leg at the end of June. Hopefully I will have the ability to record my pedaling style during the ride so I will be able to document how much and how I change during a 6 hr or so ride.

Are you doing it on PC? 6hrs seems very slow for someone putting out 260W?

 

[FrankDay]

Are you doing it on PC? 6hrs seems very slow for someone putting out 260W?

Where did you get 260W expected avg power for me for an IM? Of course I will do it on PC's. You have to understand it has been a long time since I rode 112 miles in one sitting at a race pace and I really don't know what to expect especially since I will be 70 years old. Best bike split at Ironman world championships for 70 year old's tends to be about 6 hours, an 18.6 mph pace. What I can do when I get on a race bike and put some effort into improving my aerodynamics is a big unknown. Will I be able to draw on past experience and pace appropriately? Who knows? I hope I will have the capability of going 5.5 hours but it might just as well end up being 7. I guess we will find out. It should be fun, three of the original IM teaming up for a relay. I get the bike leg.

 

[FrankDay]

Hopefully I will have the ability to record my pedaling style during the ride so I will be able to document how much and how I change during a 6 hr or so ride.

I finally have my iCranks up and talking with a beta version of the software. Right now it only works indoors but hopefully I will be able to record data such as this for the entire IM bike leg and we will be able to see what happens rather than guess. Note, there are some issues with the software most notably the output is rotated 90º

http://tinypic.com/r/2569s76/8

 

[sciguy]

Where did you get 260W expected avg power for me for an IM? Of course I will do it on PC's. You have to understand it has been a long time since I rode 112 miles in one sitting at a race pace and I really don't know what to expect especially since I will be 70 years old. Best bike split at Ironman world championships for 70 year old's tends to be about 6 hours, an 18.6 mph pace. What I can do when I get on a race bike and put some effort into improving my aerodynamics is a big unknown. Will I be able to draw on past experience and pace appropriately? Who knows? I hope I will have the capability of going 5.5 hours but it might just as well end up being 7. I guess we will find out. It should be fun, three of the original IM teaming up for a relay. I get the bike leg.

Bravo for taking this on. Nothing like pinning on a number to focus the mind and body. I guarantee you'll learn a lot during the process. Of course by doing this as a relay you will have the advantage of not having to swim for and hour and a half or so and more importantly you will not have to hold back saving yourself for the marathon. Those two factors alone should aid your goal of a fast time.

I believe you'll be surprised how little short cranks aid you in finding a nice aero postion. You've repeatedly mentioned decreased flexibility making it tougher for older athletes to get into an aero position. I've actually come to agree with you more on that subject but don't agree that shorter cranks are the cure. It's tight hamstrings/lower back that are the real problem when seeking and aero position. They come to play with an extended leg rather than retracted on. Tight hamstrings /lower back prevent one from performing the anterior pelvic tilt needed to bring bring the front of your body more parallel to the horizon. Going to shorter cranks doesn't help with his problem as the leg is still extended just as much at the bottom of the stroke as it would be with longer cranks. After spending a winter playing with crank length and body position this has become very clear to me. Now if I run my seat height lower, reducing leg extension, this does allow more anterior pelvic tilt but at a large expense of power production.

Moving the seat forward effectively rotating oneself around the bottom bracket does aid in improving one's aero postion. You'll notice UCI constrained time trialists riding the nose of their saddle to get as far forward as possible. The problem with using shorter cranks is that you must raise your saddle which effectively moves the seat even farther back compared to the bottom bracket. At least if you're like me and already have the seat positioned as far forward as possible moving rearward harms my ability to ride aero.



I look forward to hearing about you learning process.

Hugh

 

[FrankDay]

I believe you'll be surprised how little short cranks aid you in finding a nice aero postion. You've repeatedly mentioned decreased flexibility making it tougher for older athletes to get into an aero position. I've actually come to agree with you more on that subject but don't agree that shorter cranks are the cure. It's tight hamstrings/lower back that are the real problem when seeking and aero position. They come to play with an extended leg rather than retracted on. Tight hamstrings /lower back prevent one from performing the anterior pelvic tilt needed to bring bring the front of your body more parallel to the horizon. Going to shorter cranks doesn't help with his problem as the leg is still extended just as much at the bottom of the stroke as it would be with longer cranks. After spending a winter playing with crank length and body position this has become very clear to me. Now if I run my seat height lower, reducing leg extension, this does allow more anterior pelvic tilt but at a large expense of power production.

I have been playing with crank length and position for well over 2 years now. I have gone as short as 85mm and as long as 200 mm. My guess is I have more experience in this regard than anyone. I can only comment on my own experience but I can tell you that crank length has a huge impact on my being able to attain a good aero position while still developing good power. It makes no sense to me that lowering the seat and bending the knee more at BDC improves the ability to attain a good aerodynamic position and you note that it adversely affects your ability to generate power. Lowering the seat without lowering the handlebars rotates the torso up which should increase frontal area and unflattens the back. And, it makes no sense to me how bringing the femur forward enhances the ability to rotate the pelvis forward and even if it did how does rotating the pelvis forward enhance ones ability to bring the knee close to the chest? The real issue is not what is going on at BDC but what is going on at TDC because that determines how high the knee goes and, hence, how low the chest can go without losing power. How lowering the seat affects that is not clear to me. Whatever the crank length the rider should optimize the seat height to allow good power at BDC and optimize crank length to allow optimization of power and body position at TDC. At least, that is my current view. If you can give me data to suggest I am wrong I am all ears.

Now that I have the iCranks I will be able to gather some real data regarding the effects of crank length (or any other bike fit) changes on pedaling technique and power/efficiency.

Moving the seat forward effectively rotating oneself around the bottom bracket does aid in improving one's aero postion. You'll notice UCI constrained time trialists riding the nose of their saddle to get as far forward as possible. The problem with using shorter cranks is that you must raise your saddle which effectively moves the seat even farther back compared to the bottom bracket. At least if you're like me and already have the seat positioned as far forward as possible moving rearward harms my ability to ride aero.

While raising the saddle does move the seat back a tad I don't see the issue. Nothing says the rider can't move the saddle forward on the rails to be as far forward as the UCI allows. But, even if one doesn't do this, moving the saddle up and keeping the handlebars the same may move the seat back but because the torso is now rotated more forward the shoulders and head actually move forward. And, if shorter cranks allow for a lowering of the handlebars (as it frequently does) this is an even bigger issue. In fact, because of this moving the CG forward the real change that may need to be made is to move the seat back even further. Here is a superimposed picture of Courtney Ogden riding 172.5 cranks and two different very short cranks (110 and 130 I believe). It isn't perfect as it comes from different sources but I think it illustrates the point. Note that even though his seat should be further back that his head shoulders have moved substantially forward (much further forward than the seat moves back) as he has been able to rotate his torso forward.

Maybe we can simply agree that changing crank length may require many bike fit changes because where the pedals are determine everything about the bike fit.