Pedaling Efficiently

[jollyrogers]

In fairness a bit more to it than that. Choice of equipment, choice of gears, riding the fastest line, being able to attain an aero position, being injury free, well fuelled, well hydrated, not over hydrated, choosing a smooth section of road to ride on, technique through the turn, pacing at start and pacing out of the turn could lead to time differences between two riders with similar power/frontal areas/weight.

Choice of gearing, being injury free, being well fueled, and being properly hydrated, are all factors that allow a rider to produce more power.

Choice of equipment, being able to attain an aero position are factors that lead to reduced drag.

I did oversimplify a bit for the sake of argument:

-A smooth section of road. equipment (tire/tube) cchoice will/can reduce Crr and a rider's time, but is a pretty minor factor compared with power and aerodynamic drag.

-Turn technique and carrying speed out of a corner - granted, but again generally far less of a factor than W:CdA on the courses where most of us race

Pacing - again, granted level pacing or appropriately variable pacing will reduce an athlete's time, but omitted for the sake of reducing the number of variables in the argument. Also, a PM is generally a huge help in preventing an athlete from breaking the first three rules of TT racing:

1. don't start too hard
2. don't start too hard
3. don't start too hard

 

[Fday]

Seeing the Devil is in the details some of us like precision. Makes things like assessing what bike components to use rather handy.

Precision is just fine for what it is worth. The question is what does that increased precision do for the athlete? Or, exactly how much precision is necessary to optimize outcome?

Would a weight lifter perform better if the gym offered 100 gram (or 100 milligram) weights to add to the bar in training?

Would health be better off if we made our blood pressure machines accurate to 0.1 mmHG?

Would swim training improve if lap timers were accurate to 0.001 second?

The list could go on and on. Sometimes more detail or precision is an improvement and sometimes it simply complicates things.

So, yes, the devil is in the details? In the case of the PM, does more detail improve outcome? That is the only question I have asked. It appears the only evidence in the affirmative is anecdotal.

 

[jollyrogers]

Would a weight lifter perform better if the gym offered 100 gram (or 100 milligram) weights to add to the bar in training?

Would health be better off if we made our blood pressure machines accurate to 0.1 mmHG?

Would swim training improve if lap timers were accurate to 0.001 second?

The list could go on and on. Sometimes more detail or precision is an improvement and sometimes it simply complicates things.

I have not seen anyone argue that a power meter provides or should provide .009% accuracy. Most seem to be satisified with +/- 1.5% or so that PowerTap provides as long as the data is consistent and repeatable.

I can offer equally ridiculous strawman arguments that are the converse of yours, above:

-What if gym weights had no weight label and were made of materials of differing density?

-Would we have as good an idea of our cardivasucular health if we only measured blood pressure based on how hard the veins in our temples pulsed (by feel) or to the nearest 10 psi?

-Would swim training be more measurable if lap timers had no second hand?

Extreme, gnat's ass accuracy at extreme cost is not the only option available. Sure, some precision can make things complicated and that's probably why some athletes don't want to use a power meter. Having objective information as to what is happening duing exercise IS extra information to consider.

If power is so irrelevant, than why does the PC web site make claims regarding expected increases in power from PC use?

 

[Fday]

I have not seen anyone argue that a power meter provides or should provide .009% accuracy. Most seem to be satisified with +/- 1.5% or so that PowerTap provides as long as the data is consistent and repeatable.

I can offer equally ridiculous strawman arguments that are the converse of yours, above:

-What if gym weights had no weight label and were made of materials of differing density?

-Would we have as good an idea of our cardivasucular health if we only measured blood pressure based on how hard the veins in our temples pulsed (by feel) or to the nearest 10 psi?

-Would swim training be more measurable if lap timers had no second hand?

Extreme, gnat's ass accuracy at extreme cost is not the only option available. Sure, some precision can make things complicated and that's probably why some athletes don't want to use a power meter. Having objective information as to what is happening duing exercise IS extra information to consider.

If power is so irrelevant, than why does the PC web site make claims regarding expected increases in power from PC use?

What you seem to miss is the argument here is not whether it is better to have increase precision in your PM but whether the increased "precision" regarding effort feedback given by the PM shows a benefit over the previous and alternative methods of obtaining this information. The point of my post was simply to point out that at some point increasing precision makes little or no difference to outcome. It is a reasonable question to ask whether a PM is beyond this point or not for most cyclists. If all we have are anecdotal reports then the question really remains unanswered.

I have never said power is irrelevant. There are two main considerations in going fast on a bicycle, power and aerodynamics. Power is very important and we believe PC's help the rider to increase their power thru several mechanisms, not one of which requires knowing what their power is. If knowing what the power is would enhance this even more I would be all for it. It may very well be true but there simply is no strong evidence to support such a conclusion.

 

[fergie]

Precision is just fine for what it is worth. The question is what does that increased precision do for the athlete? Or, exactly how much precision is necessary to optimize outcome?

Will Hopkins has deemed that a 1% gain is worth pursuing in terms of sports performance.

Would a weight lifter perform better if the gym offered 100 gram (or 100 milligram) weights to add to the bar in training?

You can buy such weights that are magnetised if you wanted to get very accurate. At the Otago University gym all bars and dumbbells and plates have their accurate weight recorded on them.

Would health be better off if we made our blood pressure machines accurate to 0.1 mmHG?

You may want to ask a person with a Cardiovascular Health Disease that one.

Would swim training improve if lap timers were accurate to 0.001 second?

Yes if it was the psychological difference between a session with no improvement and a small improvement.

The list could go on and on. Sometimes more detail or precision is an improvement and sometimes it simply complicates things.

We all know why you would say that.

So, yes, the devil is in the details? In the case of the PM, does more detail improve outcome? That is the only question I have asked. It appears the only evidence in the affirmative is anecdotal.

Pathetic Frank, anyone can carry out their own experiment to compare HR, RPE, time vs the quality of feedback a power meter gives.

 

[fergie]

What you seem to miss is the argument here is not whether it is better to have increase precision in your PM but whether the increased "precision" regarding effort feedback given by the PM shows a benefit over the previous and alternative methods of obtaining this information.

And we have given sufficient examples from most areas of life where the answer is YES, there is a benefit. But you choose to bury your head in the sand because these tools show your product is a waste of time and money.

The point of my post was simply to point out that at some point increasing precision makes little or no difference to outcome.

Of course there is a point of diminishing returns. There is in anything but if you took your head out of the sand you would see that majority of good studies on performance improvements in cycling use power as the main criteria. What else do they use. Efficiency hasn't worked to well for you with the Gimmickcranks has it Frank. Only Lutrell and Poitenger and that study was a joke.

It is a reasonable question to ask whether a PM is beyond this point or not for most cyclists. If all we have are anecdotal reports then the question really remains unanswered.

It's not anecdotal when you have hard data. I can show that I have done X amount of hours at Y amount of wattage for the last 4 years. When Marco Pinotti claims a Gimmickcrank has made him 15% stronger this is an anecdote. How can you prove it was only the cranks when Pinotti is on a team that is pushing the boundaries of sport science in terms of training, recovery and nutrition.

I have never said power is irrelevant. There are two main considerations in going fast on a bicycle, power and aerodynamics. Power is very important and we believe PC's help the rider to increase their power thru several mechanisms, not one of which requires knowing what their power is. If knowing what the power is would enhance this even more I would be all for it. It may very well be true but there simply is no strong evidence to support such a conclusion.

What horse s**t! So we are back to a matter of faith. What other impulse is there to propel the bike forward Frank. What are these mechanisms and how can any not involve power delivery to propel the bike forward? Only one I can think of is gravity.

 

[swampy1970]

The problem is there is no method of power training. Training hasn't changed from a mix of endurance training, interval training and sprint training. Some love to complicate things by throwing up special techniques like big gear work or toys like Gimmickcranks.

Some "tools" can help one pin point an area in which you may be lacking. For me, using the PC's helped the times on the "hill test" come down and when I got a PM the watts went up.

A Power meter is the tool used to measure the propulsion of the bike. It doesn't measure the resistance one rides against, the nutritional/hydration status, motivation or physiological effect of riding so anyone claiming winning bike races is ....

I see your home boy Hayden Roulston has been making some fun claims...

... apparently Sports Oxyshots increase his oxygen uptake by upto 6%. I thought you Kiwi's were all about sports science.

Did he notice an improvement on his power meter?

 

[fergie]

Some "tools" can help one pin point an area in which you may be lacking. For me, using the PC's helped the times on the "hill test" come down and when I got a PM the watts went up.

There could be many reasons why your performance went up that day. What is notable is that you used a power meter to measure them.

I see your home boy Hayden Roulston has been making some fun claims...

... apparently Sports Oxyshots increase his oxygen uptake by upto 6%. I thought you Kiwi's were all about sports science.

Hayden's plan B in life is working in a Meat Processing Plant with the rest of his family in Tinwald. Hence when diagnosed with a heart arrhythmia he decided to return to racing against medical advice. I wouldn't confuse marketing with sport science but seeing your a Gimmickcranker I think it's possibly too late

Did he notice an improvement on his power meter?

Yes he does use a SRM to monitor his training and racing.

 

[Fday]

Riding velodromes requires a highly variable pace. Speed goes up in the bends and power goes down and vice versa on the straights. In the pursuit final of a NZ champ one rider was down to 320 watts in the bends and peaked at 530 watts on the straights. Hence the use of a higher cadence to handle the rhythm changes that happen every 4-6sec each lap.

Hey Fergie, I thought I would bring this back up because I would like to know if you can explain what is going on here for the "masses"(as if anyone would classify the few still viewing this thread as "masses") who may not understand or who may think you just mistyped.

In general, one would expect higher speed to require higher power yet above your write: "Speed goes up in the bends and power goes down and vice versa on the straights." Anyhow, just thought I would find out if you could explain why this is so without violating the laws of thermodynamics.

Thanks for sticking around.

 

[swampy1970]

There could be many reasons why your performance went up that day. What is notable is that you used a power meter to measure them.

I also measured the 'other' variables that I'd noted before during earlier tests with the Polar CS600 (no power).

There could be many reasons why I rode better than day - but that days ride was very similar to the rides in the following weeks done during normal training. Nothing out of the ordinary - just faster than the period when I last tested.

That I measured power output has no bearing on the fact that I went significantly faster. It might be notable to some, but during that test it was just added weight on the bike, a different coloured computer that ultimately gave an extra variable to keep track of for future testing. Initial tests with the PowerTap were done without using it for pacing, just as I had done with the Polar.

That extra data point did start to highlight a weirdness in my hillclimbing though - namely why do I find it much harder to ride at a given power than I do on the flat and why do I find it hard to maintain a given power on varying gradients given that RPE feels the same. Now that's something that the power meter has been very useful for and just like the PC's it's just another tool that I've found beneficial.

I just wish these 'tools' weren't so fecking expensive.

 

[roadhouse]

Hey Fergie, I thought I would bring this back up because I would like to know if you can explain what is going on here for the "masses"(as if anyone would classify the few still viewing this thread as "masses") who may not understand or who may think you just mistyped.

In general, one would expect higher speed to require higher power yet above your write: "Speed goes up in the bends and power goes down and vice versa on the straights." Anyhow, just thought I would find out if you could explain why this is so without violating the laws of thermodynamics.

Thanks for sticking around.

Kind of related, I watched my first NZ track cycling event on Universal Sports just a few days which included Finley, Pendelton and that huge Dutch guy whom won and set some records and man are those guys fast. I really enjoyed that cat 'n' mouse two rider event where one person stalks the other for a bit while just about track standing ( illegal if they actually stop pedaling) and then it's all out war for one final lap.

Just wanted to say that.

 

[fergie]

Ummm Roadie Check your Meds, Phinney and Pendalton have never been to NZ, Pendalton's parents have.

Swampy so you really have no idea why you went faster but good to see you using a power meter to measure it.

Frank, so you are a Nuclear Sub Engineer yet you don't understand the kinematics of riding a banked velodrome. Not looking good for your chap riding the Hour Record.

From an outdoor track with tightly banked bends...

Straights Peak Power 538 watts Speed Drops to 50kph.
Bends Power drops to 320 watts Speed Peaks at 53.9kph

So we can add riding a banked velodrome to ways for the bike to travel faster without more power to gravity

Including lean in the analysis of a general model of a rider on a surface leads to several important conclusions:

The faster the rider, the shorter the distance. As a rider leans in the turns, the rider's center of mass travels a shorter path than the rider's wheel.

The taller a rider's center of mass, the shorter the distance. The length of the path of a rider's center of mass in a turn depends on the height of the rider's center of mass. The greater the height, the shorter the path in the turn.

The shorter distance contributes significantly to faster times. It's not just that powerful riders go faster, they also travel a shorter distance through the turns.

Times depend on the configuration of the velodrome. Velodromes with longer straights will have shorter distances in the turns (for a given length). This gives different radii and different speeds for nominally the same path.

Speeds in the turns are faster because potential energy is converted to speed as the rider leans. This is offset by increased drag from the faster speed. The rider looses this speed when potential energy increases in the straights.

 

[swampy1970]

Swampy so you really have no idea why you went faster but good to see you using a power meter to measure it.

When you only change one thing, you have a good idea why you started improving at a fast rate...

 

[Fday]

Originally Posted by Analytical Cycling
Including lean in the analysis of a general model of a rider on a surface leads to several important conclusions:

The faster the rider, the shorter the distance. As a rider leans in the turns, the rider's center of mass travels a shorter path than the rider's wheel.

The taller a rider's center of mass, the shorter the distance. The length of the path of a rider's center of mass in a turn depends on the height of the rider's center of mass. The greater the height, the shorter the path in the turn.

The shorter distance contributes significantly to faster times. It's not just that powerful riders go faster, they also travel a shorter distance through the turns.

Times depend on the configuration of the velodrome. Velodromes with longer straights will have shorter distances in the turns (for a given length). This gives different radii and different speeds for nominally the same path.

Speeds in the turns are faster because potential energy is converted to speed as the rider leans. This is offset by increased drag from the faster speed. The rider looses this speed when potential energy increases in the straights.

From an outdoor track with tightly banked bends...

Straights Peak Power 538 watts Speed Drops to 50kph.
Bends Power drops to 320 watts Speed Peaks at 53.9kph

So we can add riding a banked velodrome to ways for the bike to travel faster without more power to gravity

Well, my engineering degree is going to come in handy here me thinks. Apparently both yours and analytical cycling's understanding of the physics here are wrong. It is impossible from a thermodynamics or physics sense for speed and drag to increase and power to decrease at the same time (see the underlined text above). It is possible to explain it but their explanation is wrong. They got close because they understand the upper body is moving a shorter distance (going slower) but this speeding up due to a change in potential energy cannot account for entire difference, there just isn't enough change there. I think you will find, if you analyze the scenario carefully, it is a conservation of momentum thing. When the upper body slows down, to keep the momentum constant the lower body and the wheels must speed up. Speed is measured by the wheels (if speed were being measured by a GPS unit on the riders head the situation would be completely reversed). Power drops because the major drag component is going slower. When the track straightens up and the body and the rider are going the same speed the wheels slow back down and the major drag component speeds up, causing power to increase. It is that simple.

 

[fergie]

When you only change one thing, you have a good idea why you started improving at a fast rate...

But there is never only one thing influencing how you perform on each day. Especially out on the road. It's hard enough work replicating conditions in a lab to ensure reliable data. Thousands of little physiological, psychological and technical parameters to control for so to think that you are only making one change is nonsense.

 

[fergie]

Yes there is that as well Frank, doesn't alter the hard data that power goes up and speed goes down in the straights and pursuiting on the track isn't a constant paced effort hence pursuiters using higher cadences than they would on the road.

 

[Fday]

Yes there is that as well Frank, doesn't alter the hard data that power goes up and speed goes down in the straights and pursuiting on the track isn't a constant paced effort hence pursuiters using higher cadences than they would on the road.

I simply asked you to explain the dichotomy as to how the power dropped when the speed increased and vice-versa. You simply regurgitated something that someone else put forth that happened to be wrong. When the correct explanation was pointed out you say "that too".

And, the "non-constant" effort doesn't make much sense as an explanation for a high cadence to me. Of more concern is the non-constant speed. The increase in wheel speed during the turns must result in an increased cadence in the turns. But, this speed difference is reasonably small so it doesn't seem that it would be a big deal. If it is a big deal it would seem the rider is at too high a cadence. So, again, why on earth does a "high cadence" facilitate the rider alternating taking it easy and going hard? Seems to me that going easy and hard is relatively cadence independent.

 

[swampy1970]

But there is never only one thing influencing how you perform on each day. Especially out on the road. It's hard enough work replicating conditions in a lab to ensure reliable data. Thousands of little physiological, psychological and technical parameters to control for so to think that you are only making one change is nonsense.

If there was a big difference from day to day then fair enough, but there isn't.

When you ride a climb enough to have a good idea that you're improving (ie times are consistently dropping) and the margin of improvement isn't just a few seconds here and there then you can get, at the very least, a good trend that very strongly suggests that you've improved...

Thankfully, I have a 'nice' hill that's sheltered from the wind (not that there's much wind in the AM and it's on the SE section of the mountain ridge which is sheltered from any small breeze coming in from the Bay) and demands an all out effort. The biggest environmental factor is how many flies you swallow on the way up if you're out on the hill past 11am. Jonathon Vaughters likened it to the infamous Angliru in Spain after racing up it in 2003.

There are times when my cyclical weight loss and weight gain comes in useful

 

[Enriss]

Seems to me that going easy and hard is relatively cadence independent.

On a fixed gear?

 

[fergie]

I simply asked you to explain the dichotomy as to how the power dropped when the speed increased and vice-versa. You simply regurgitated something that someone else put forth that happened to be wrong. When the correct explanation was pointed out you say "that too".

Because as a coach I don't need to know the details of why it happens, I just know it happens and plan accordingly, it's called knowing the demands of your event.

Seems to me that going easy and hard is relatively cadence independent.

But you have been arguing for a specific cadence on Slowtwitch and you plan to run a chap at the Hour Record at 60rpm.

Swampy you "think" there is no difference but there is. Can you say the weather was the same during the ride day on day out, your hydration levels were the same, your diet was the same, alcohol intake was the same, fatigue levels, smog, alien activity levels in you area, tyre pressure, gear selection, RPE, the list was endless were all the same for each ride leaving your Gimmickcrank the only constant?