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2016-01-26 2:01 PM
in reply to: 3mar

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Subject: RE: Efficiency Losses on the Bike

how hard it feels has nothing to do with the power output, speed, or aerodynamics.



2016-01-26 2:04 PM
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Subject: RE: Efficiency Losses on the Bike
Originally posted by 3mar
Is maintaining 200 watts on a windy course more physically taxing than maintaining 200 watts on a calm course? It certainly feels that way.


I don't know the reasons why but it certainly feels that way to me.

Originally posted by 3mar
The temperature however I see a bit difference. Hotter air may mean lower density, however, it also means that at some point your body has to expend energy keeping you cool which will be detrimental to performance (maybe not power, as that is separate, but it would be hard to produce the same power). Just thinking out loud.


For sure. Hotter is faster for the same watts, but the same watts are harder on the body when it's warm



Edited by marcag 2016-01-26 2:05 PM
2016-01-26 2:05 PM
in reply to: Left Brain

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Subject: RE: Efficiency Losses on the Bike

Within a single session, we have testing of a road helmet versus an aero helmet -- say eight runs (three miles out, three miles back per run) total, so one road helmet, one aero helmet, road, aero, road, aero, road aero.  That gives us a comparison of this helmet versus that.

Then the same thing but with training wheels versus race wheels.

And again with sleeveless tri suit versus sleeved top.

Also did it with seat height, arm width, bar height, etc.

In the end, it's very easy to see how much each item impacted speed given the same power.  My 750 miles (plus all of the other bike training I did in addition) allowed me to ride at 150W without overbiking, but the aero testing allowed me to ride faster at that 150W.  It's pretty simple, really, but you have to be willing to put in the effort to analyze the data.

Sure, if you're a super biker, who cares about optimizing position?  But I'm not a super biker....I'm an okay biker who can save a decent amount of time by figuring out what works best for me. 

2016-01-26 2:05 PM
in reply to: 3mar

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Subject: RE: Efficiency Losses on the Bike

Originally posted by 3mar 

I hadn't thought about the air density changes, that is interesting. This also brings me to another point, and that is physiological differences. I guess it makes sense that going into and out of the wind cancels itself out based on power, but what about fatigue? Is maintaining 200 watts on a windy course more physically taxing than maintaining 200 watts on a calm course? It certainly feels that way. Probably due to variable efforts (going too hard against the wind and too easy with it...even with a PM that's hard to control). But if you could nail a steady power, would your physical effort also even out? Same for a hilly course with net 0 elevation gain? The temperature however I see a bit difference. Hotter air may mean lower density, however, it also means that at some point your body has to expend energy keeping you cool which will be detrimental to performance (maybe not power, as that is separate, but it would be hard to produce the same power). Just thinking out loud.

If you hold steady power, 200w for x time should be the same physical toll.  But, on the same course, your time will change due to wind so it will get harder/easier due to the time factor.  Also, in stronger wind conditions--especially cross-winds, you might use energy just holding your bike steady on a straight line.  That is, you won't just be working to drive 200w to the wheel but might also be straining other, smaller muscles to help you navigate the bike.  In addition to whatever physical toll this extracts (probably not huge but, depending on time & conditions, perhaps not negligible), it can be very mentally draining.

2016-01-26 2:14 PM
in reply to: 3mar

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Subject: RE: Efficiency Losses on the Bike
3mar,

There is also this paper from : Robert Chung http://anonymous.coward.free.fr/wattage/cda/indirect-cda.pdf
I suggest you take a look at Aerolab in Golden Cheetah. It allows you to do some analysis on aerodynamics
There is also a great thread on ST called the Platypus thread on testing.

My comment on Andy and Robert was to Nicole's comment that you can't test outdoors. You can.

2016-01-26 2:14 PM
in reply to: marcag

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Subject: RE: Efficiency Losses on the Bike
What you are seeing yourself is the reason why coaches never tell their athletes to set goals on the bike based on speed. There are too many variables to make it realistic, and if it's a bad day for one of many reasons (weather being a big one) then you get frustrated but in reality you could still be performing your best based on the conditions.

Now, obviously, It can be a lot of fun as a data geek to fixate on all these variables and analyze what the cause and effect are, and this can help you minimize them come race day. On the flip side, that is a lot of work to track all the variables and in the end there are many you can't control.

So in short... yes. This is normal lol


2016-01-26 2:24 PM
in reply to: marcag

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Subject: RE: Efficiency Losses on the Bike
Originally posted by marcag

3mar,

There is also this paper from : Robert Chung http://anonymous.coward.free.fr/wattage/cda/indirect-cda.pdf
I suggest you take a look at Aerolab in Golden Cheetah. It allows you to do some analysis on aerodynamics
There is also a great thread on ST called the Platypus thread on testing.

My comment on Andy and Robert was to Nicole's comment that you can't test outdoors. You can.




I will most definitely take a look at those. Thanks!
2016-01-26 2:33 PM
in reply to: 3mar

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Subject: RE: Efficiency Losses on the Bike
As a general note; I'm not trying to figure out some a priori, analytical calculation for power vs speed based on riding conditions and equipment, etc. (personally and professionally I always lean a posteriori/ empirical) What I'm trying to figure out is what are the big factors in efficiency. It all started when I looked at two particular rides on the same course where my speed was identical but my power was very different. I had always assumed that it was due to one day being windy, and the other not. When it's windy, I just say, ok, this is going to be a slow day, vs calm weather, where I tell myself, now I can get some speed. Turns out, looking at the data, that has little to no effect. That was interesting, and the reason I shared.

This brought me to what did cause this anomaly. Based on some of the other posts, I went back and looked at effort on these two rides (and I get it, two data points can't tell the whole story, which is why I plotted all my outdoor rides over the past couple months...but bringing it back to where it started, let's look at these two). I grabbed my average HR and here's what they look like:

Ride 1/Ride 2
Speed: 20.9 / 20.7
Power: 197 / 170
Ave HR: 137 / 129
Temp: 35 / 64
Wind: 9 / 12

Everything up there is generally the same except for power, HR and temp. The HR and power are properly correlated; I worked harder for the higher power and that makes sense. So how is the speed the same? It then comes down to temp. The main difference that I came up with was that I was wearing a baggy jacket on one ride and not the other. I'm just surprised at the 27 watt difference for a stinking jacket. Makes you think twice about what you wear.
2016-01-26 2:34 PM
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Subject: RE: Efficiency Losses on the Bike

.

Originally posted by 3mar  .... But if you could nail a steady power, would your physical effort also even out? Same for a hilly course with net 0 elevation gain?...

Last spring I lived in the Texas Hill Country.  As you might imagine I trained on some routes with extreme hills. It really didn't make a difference in my average speed over an out and back course.  I might be going 7 MPH up a steep incline going out but coming back I would be coming down at 35 MPH.  At the end of the ride my average speeds would be about the same for a really hilly course as it was for a fairly flat course (in such a thing exists in the Hill Country).  So for me, an equal effort on a flat course resulted on no better MPH averages than I saw on a hilly course.  

Note: Race day in Hill country had a course that finished 6 miles up hill from the start.  I don't remember what the elevation change was, but when i road it in practice my average speed was lower than my worst out and back on the most hilly course.  On race day though I rode that course faster than any of my training rides.  There defiantly is something to the physiology.  I can never come close to matching in training what I do on race day.  :-)      



Edited by BlueBoy26 2016-01-26 2:39 PM
2016-01-26 2:40 PM
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Subject: RE: Efficiency Losses on the Bike
Originally posted by 3mar

As a general note; I'm not trying to figure out some a priori, analytical calculation for power vs speed based on riding conditions and equipment, etc. (personally and professionally I always lean a posteriori/ empirical) What I'm trying to figure out is what are the big factors in efficiency. It all started when I looked at two particular rides on the same course where my speed was identical but my power was very different. I had always assumed that it was due to one day being windy, and the other not. When it's windy, I just say, ok, this is going to be a slow day, vs calm weather, where I tell myself, now I can get some speed. Turns out, looking at the data, that has little to no effect. That was interesting, and the reason I shared.

This brought me to what did cause this anomaly. Based on some of the other posts, I went back and looked at effort on these two rides (and I get it, two data points can't tell the whole story, which is why I plotted all my outdoor rides over the past couple months...but bringing it back to where it started, let's look at these two). I grabbed my average HR and here's what they look like:

Ride 1/Ride 2
Speed: 20.9 / 20.7
Power: 197 / 170
Ave HR: 137 / 129
Temp: 35 / 64
Wind: 9 / 12

Everything up there is generally the same except for power, HR and temp. The HR and power are properly correlated; I worked harder for the higher power and that makes sense. So how is the speed the same? It then comes down to temp. The main difference that I came up with was that I was wearing a baggy jacket on one ride and not the other. I'm just surprised at the 27 watt difference for a stinking jacket. Makes you think twice about what you wear.



Drop those two rides in Aerolab. Depending on wind you will see the difference in cda and you can account for temperature. Let me know if you need help.

Unfortunately, people are leaving lots of time on the table by making bad clothing decisions


Edited by marcag 2016-01-26 2:40 PM
2016-01-26 3:00 PM
in reply to: marcag

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Subject: RE: Efficiency Losses on the Bike

Originally posted by marcag
Originally posted by 3mar As a general note; I'm not trying to figure out some a priori, analytical calculation for power vs speed based on riding conditions and equipment, etc. (personally and professionally I always lean a posteriori/ empirical) What I'm trying to figure out is what are the big factors in efficiency. It all started when I looked at two particular rides on the same course where my speed was identical but my power was very different. I had always assumed that it was due to one day being windy, and the other not. When it's windy, I just say, ok, this is going to be a slow day, vs calm weather, where I tell myself, now I can get some speed. Turns out, looking at the data, that has little to no effect. That was interesting, and the reason I shared. This brought me to what did cause this anomaly. Based on some of the other posts, I went back and looked at effort on these two rides (and I get it, two data points can't tell the whole story, which is why I plotted all my outdoor rides over the past couple months...but bringing it back to where it started, let's look at these two). I grabbed my average HR and here's what they look like: Ride 1/Ride 2 Speed: 20.9 / 20.7 Power: 197 / 170 Ave HR: 137 / 129 Temp: 35 / 64 Wind: 9 / 12 Everything up there is generally the same except for power, HR and temp. The HR and power are properly correlated; I worked harder for the higher power and that makes sense. So how is the speed the same? It then comes down to temp. The main difference that I came up with was that I was wearing a baggy jacket on one ride and not the other. I'm just surprised at the 27 watt difference for a stinking jacket. Makes you think twice about what you wear.
Drop those two rides in Aerolab. Depending on wind you will see the difference in cda and you can account for temperature. Let me know if you need help. Unfortunately, people are leaving lots of time on the table by making bad clothing decisions

I you call my tu-tu not aero one more time I swear.....



2016-01-26 3:02 PM
in reply to: dmiller5

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Subject: RE: Efficiency Losses on the Bike
Originally posted by dmiller5

Originally posted by marcag
Originally posted by 3mar As a general note; I'm not trying to figure out some a priori, analytical calculation for power vs speed based on riding conditions and equipment, etc. (personally and professionally I always lean a posteriori/ empirical) What I'm trying to figure out is what are the big factors in efficiency. It all started when I looked at two particular rides on the same course where my speed was identical but my power was very different. I had always assumed that it was due to one day being windy, and the other not. When it's windy, I just say, ok, this is going to be a slow day, vs calm weather, where I tell myself, now I can get some speed. Turns out, looking at the data, that has little to no effect. That was interesting, and the reason I shared. This brought me to what did cause this anomaly. Based on some of the other posts, I went back and looked at effort on these two rides (and I get it, two data points can't tell the whole story, which is why I plotted all my outdoor rides over the past couple months...but bringing it back to where it started, let's look at these two). I grabbed my average HR and here's what they look like: Ride 1/Ride 2 Speed: 20.9 / 20.7 Power: 197 / 170 Ave HR: 137 / 129 Temp: 35 / 64 Wind: 9 / 12 Everything up there is generally the same except for power, HR and temp. The HR and power are properly correlated; I worked harder for the higher power and that makes sense. So how is the speed the same? It then comes down to temp. The main difference that I came up with was that I was wearing a baggy jacket on one ride and not the other. I'm just surprised at the 27 watt difference for a stinking jacket. Makes you think twice about what you wear.
Drop those two rides in Aerolab. Depending on wind you will see the difference in cda and you can account for temperature. Let me know if you need help. Unfortunately, people are leaving lots of time on the table by making bad clothing decisions

I you call my tu-tu not aero one more time I swear.....




No no, never.
Train with the tu-tu, race with the leotards
2016-01-26 3:10 PM
in reply to: 3mar

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Subject: RE: Efficiency Losses on the Bike

Originally posted by 3mar Besides...the forum has been a bit boring lately, just trying to strike up an interesting conversation.

Golf clap...well done sir!

2016-01-26 3:22 PM
in reply to: Jason N

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Subject: RE: Efficiency Losses on the Bike
Originally posted by Jason N

Originally posted by 3mar Besides...the forum has been a bit boring lately, just trying to strike up an interesting conversation.

Golf clap...well done sir!




and I even managed to get Marc and LB to argue...but that's not very hard, is it?
2016-01-26 3:27 PM
in reply to: 3mar

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Subject: RE: Efficiency Losses on the Bike
Originally posted by 3mar

Originally posted by Jason N

Originally posted by 3mar Besides...the forum has been a bit boring lately, just trying to strike up an interesting conversation.

Golf clap...well done sir!




and I even managed to get Marc and LB to argue...but that's not very hard, is it?


it's unfortunate you can't have a fact based conversation in TT.
Maybe that's why the level of conversation in TT is what it is.
Oh well.
2016-01-26 3:33 PM
in reply to: marcag

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Subject: RE: Efficiency Losses on the Bike
Originally posted by marcag

Originally posted by 3mar

Originally posted by Jason N

Originally posted by 3mar Besides...the forum has been a bit boring lately, just trying to strike up an interesting conversation.

Golf clap...well done sir!




and I even managed to get Marc and LB to argue...but that's not very hard, is it?


it's unfortunate you can't have a fact based conversation in TT.
Maybe that's why the level of conversation in TT is what it is.
Oh well.


Well don't knock TT too much, it's where I get 90% of my information about triathlon


2016-01-26 3:34 PM
in reply to: marcag

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Subject: RE: Efficiency Losses on the Bike

Originally posted by marcag
Originally posted by 3mar
Originally posted by Jason N

Originally posted by 3mar Besides...the forum has been a bit boring lately, just trying to strike up an interesting conversation.

Golf clap...well done sir!

and I even managed to get Marc and LB to argue...but that's not very hard, is it?
it's unfortunate you can't have a fact based conversation in TT. Maybe that's why the level of conversation in TT is what it is. Oh well.

Well, I didn't know what Andy's last name was before reading this thread...so at least I learned something new today.

2016-01-26 5:00 PM
in reply to: triathlonpal07

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Subject: RE: Efficiency Losses on the Bike
Originally posted by triathlonpal07

What you are seeing yourself is the reason why coaches never tell their athletes to set goals on the bike based on speed.


Here is why. You're a data geek so here ya go

Earlier on, we said the power to overcome drag was
AD = 1/2 * rho (air density) * cda * AirSpeed ^2 * Ground Velocity

A typical rho may be 1.2
A typical cda may be .26
21mph is 9.33ms

assume no wind. To hit 21mph
1/2 * 1.2 * .26 * 9.33^2 * 9.33 = 126watts to overcome drag. There are watts for rolling resistance and hills but this is the drag component

If there is a 5mph (2.2m/s) headwind that becomes
1/2 * 1.2 * .26 * (9.33+2.22)^2 * 9.33 = 194 watts

Now for Nicole for example, her threshold is 191w. She was riding at 150 (~80%).

Had she been riding to speed, she would have had to ride at 72watts more to hit her target speed, way over threshold and she would have been toast in 20minutes.

With the tail wind,riding to speed, she would have only needed 74watts (to overcome drag) to hit that same speed. Way under target. So a very uneven ride.

This is why you don't ride to speed if there is wind.

Now going back to the cda. Nicole changed from .26 to .21. In the no wind condition, this required 102 watts rather than the 126. 24watts less. This means her threshold would have had to be (24/.8) = 30 watts higher. Tell me that 30 watts is not worth testing for.

2016-01-26 10:45 PM
in reply to: marcag

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Subject: RE: Efficiency Losses on the Bike

Originally posted by marcag
Originally posted by 3mar
Originally posted by Jason N

Originally posted by 3mar Besides...the forum has been a bit boring lately, just trying to strike up an interesting conversation.

Golf clap...well done sir!

and I even managed to get Marc and LB to argue...but that's not very hard, is it?
it's unfortunate you can't have a fact based conversation in TT. Maybe that's why the level of conversation in TT is what it is. Oh well.

There is NOTHING "fact based" in saying that someone spent 750 miles getting their aero dialed in and because of that "dialing in" they had a great bike.  It could just as easily been the 750 miles they spent "training" as it was the "dialing in".    Ride no extra miles and get tested in a wind tunnel to see what setup is most aero and you can make the statement.  Riding on the road with constantly changing variables doesn't cut it........ESPECIALLY not at the AG level.

2016-01-27 5:23 AM
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Subject: RE: Efficiency Losses on the Bike
Originally posted by Left Brain

Originally posted by marcag
Originally posted by 3mar
Originally posted by Jason N

Originally posted by 3mar Besides...the forum has been a bit boring lately, just trying to strike up an interesting conversation.

Golf clap...well done sir!

and I even managed to get Marc and LB to argue...but that's not very hard, is it?
it's unfortunate you can't have a fact based conversation in TT. Maybe that's why the level of conversation in TT is what it is. Oh well.

There is NOTHING "fact based" in saying that someone spent 750 miles getting their aero dialed in and because of that "dialing in" they had a great bike.  It could just as easily been the 750 miles they spent "training" as it was the "dialing in".    Ride no extra miles and get tested in a wind tunnel to see what setup is most aero and you can make the statement.  Riding on the road with constantly changing variables doesn't cut it........ESPECIALLY not at the AG level.




A fact is her FTP was 192w and she rode at 150w. This ability was based on training and training alone. This is the overwhelming reason for her good bike. Aero testing doesn't replace hard work and getting fit.

A fact is her measured CDA was ,26 last summer and .21 in the race. CDA has nothing to do with fitness. It's all position and equipment optimization, tested while she was also training. She followed a very specific way of testing.

A fact is a good bike is the result of both. You need the fitness to generate the watts you need the efficiency to turn them into speed

A fact is you can achieve the same thing in a wind tunnel. At $400 per hour. Most people having to drive many hours away, you can absolutely do it in a wind tunnel. It's the best way to do it. But it is damn expensive and not always accessible.

Now the ability to test outdoor, some people come up with theoretical reason why it can't be done. The Chung method (I sent a link before) says it can be done and several people have shown it to work. If you don't believe in it, that is certainly an opinion. Wind Tunnels and Velodromes provide much better testing conditions but they are not affordable and accessible for some.

As for your comment on "at the AG level", testing applies equally to anyone that is racing. It's not super simple so yes it's beyond some people's technical level. That is why people needing help can get it through conversation in this forum. If people want to hijack it, I guess they can do that but they aren't providing any value to other readers.



Edited by marcag 2016-01-27 5:53 AM
2016-01-27 7:30 AM
in reply to: JohnnyKay

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Subject: RE: Efficiency Losses on the Bike
Originally posted by JohnnyKay

If you hold steady power, 200w for x time should be the same physical toll. 



I don't think I can agree with this statement.

If you hold 200W for an hour on a 100°F day it will have more of a toll on you than doing the same thing on a 60°F day.

Your body produces heat when it works and must transfer that heat to the environment which will happen more efficiently on a cooler day.
Also on as Marq said the air density changes so on a cool day you pull in more oxygen when you take a breath on a cool day.

If your talking about 5°-10°F difference the effects are minimal, but with larger differentials as well as changes in humidity there will be a difference.


2016-01-27 7:50 AM
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Subject: RE: Efficiency Losses on the Bike
Originally posted by mike761

Originally posted by JohnnyKay

If you hold steady power, 200w for x time should be the same physical toll. 



I don't think I can agree with this statement.

If you hold 200W for an hour on a 100°F day it will have more of a toll on you than doing the same thing on a 60°F day.

Your body produces heat when it works and must transfer that heat to the environment which will happen more efficiently on a cooler day.
Also on as Marq said the air density changes so on a cool day you pull in more oxygen when you take a breath on a cool day.

If your talking about 5°-10°F difference the effects are minimal, but with larger differentials as well as changes in humidity there will be a difference.


FYI, a difference in 10deg F, at a constant humidity and barometric pressure could be about 2.3% in watts. This is one of the challenges of testing outdoor when you start early in the morning and test for hours. Rising temps change the data and it must be accounted for.

Edited by marcag 2016-01-27 7:51 AM
2016-01-27 8:30 AM
in reply to: Left Brain

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Subject: RE: Efficiency Losses on the Bike
Originally posted by Left Brain

Originally posted by marcag
Originally posted by 3mar
Originally posted by Jason N

Originally posted by 3mar Besides...the forum has been a bit boring lately, just trying to strike up an interesting conversation.

Golf clap...well done sir!

and I even managed to get Marc and LB to argue...but that's not very hard, is it?
it's unfortunate you can't have a fact based conversation in TT. Maybe that's why the level of conversation in TT is what it is. Oh well.

There is NOTHING "fact based" in saying that someone spent 750 miles getting their aero dialed in and because of that "dialing in" they had a great bike.  It could just as easily been the 750 miles they spent "training" as it was the "dialing in".    Ride no extra miles and get tested in a wind tunnel to see what setup is most aero and you can make the statement.  Riding on the road with constantly changing variables doesn't cut it........ESPECIALLY not at the AG level.




So you race in ever changing conditions, but it's better to test in a controled environment?

In my thought process, and in my job: analytical calculation < lab testing < pilot testing < full scale

I'd put wind tunnel testing in the "lab testing" group with pilot testing = road tests.
2016-01-27 9:35 AM
in reply to: Left Brain

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Subject: RE: Efficiency Losses on the Bike

Originally posted by Left Brain

Originally posted by marcag
Originally posted by 3mar
Originally posted by Jason N

Originally posted by 3mar Besides...the forum has been a bit boring lately, just trying to strike up an interesting conversation.

Golf clap...well done sir!

and I even managed to get Marc and LB to argue...but that's not very hard, is it?
it's unfortunate you can't have a fact based conversation in TT. Maybe that's why the level of conversation in TT is what it is. Oh well.

There is NOTHING "fact based" in saying that someone spent 750 miles getting their aero dialed in and because of that "dialing in" they had a great bike.  It could just as easily been the 750 miles they spent "training" as it was the "dialing in".    Ride no extra miles and get tested in a wind tunnel to see what setup is most aero and you can make the statement.  Riding on the road with constantly changing variables doesn't cut it........ESPECIALLY not at the AG level.

 

I like that you conveniently ignored my last post where it makes it very obvious that testing made the difference in optimizing, and doing all of my training (which, yes, includes the testing) allowed me to ride at that power.  I'll post it again for you here, though I suspect you'll continue to ignore it.

 

Within a single session, we have testing of a road helmet versus an aero helmet -- say eight runs (three miles out, three miles back per run) total, so one road helmet, one aero helmet, road, aero, road, aero, road aero.  That gives us a comparison of this helmet versus that.

Then the same thing but with training wheels versus race wheels.

And again with sleeveless tri suit versus sleeved top.

Also did it with seat height, arm width, bar height, etc.

In the end, it's very easy to see how much each item impacted speed given the same power.  My 750 miles (plus all of the other bike training I did in addition) allowed me to ride at 150W without overbiking, but the aero testing allowed me to ride faster at that 150W.  It's pretty simple, really, but you have to be willing to put in the effort to analyze the data.

Sure, if you're a super biker, who cares about optimizing position?  But I'm not a super biker....I'm an okay biker who can save a decent amount of time by figuring out what works best for me. 

2016-01-28 8:15 AM
in reply to: Left Brain

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Subject: RE: Efficiency Losses on the Bike
Originally posted by Left Brain

There is NOTHING "fact based" in saying that someone spent 750 miles getting their aero dialed in and because of that "dialing in" they had a great bike.  It could just as easily been the 750 miles they spent "training" as it was the "dialing in".    Ride no extra miles and get tested in a wind tunnel to see what setup is most aero and you can make the statement.  Riding on the road with constantly changing variables doesn't cut it........ESPECIALLY not at the AG level.


I'm pretty sure that nobody is saying that the extra riding would not have led to fitness improvements and would have likely been part of the overall equation that led to a great bike split. However, the point is that one can build fitness and work on the details (not only aero but also good tires/tubes, clean and lubed drivetrain, etc) - while it is unlikely that any one detail is isolation will make a huge difference, the sum of addressing the details can make the difference between a good bike split and a great bike split.

It is quite easy to pay attention to the details and between rolling resistance, aero dynamic and frictional losses, save about 5s/km. Using the rough rule of thumb, in order to do that purely based on fitness gains, the athlete would need to improve their race power by about 50W (and their FTP by more than 50W). Even if just riding more would give them the 50W improvement on race day power, why not combine that with a good position and smart equipment choices and go even faster?

Shane
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