Cycling and bicycle discussion forums. 
   Click here to join our community Log in to access your Control Panel  


Go Back   > >

"The 33"-Road Bike Racing We set this forum up for our members to discuss their experiences in either pro or amateur racing, whether they are the big races, or even the small backyard races. Don't forget to update all the members with your own race results.

User Tag List

Reply
 
Thread Tools Search this Thread
Old 12-03-08, 11:44 AM   #76
tanhalt
Senior Member
 
tanhalt's Avatar
 
Join Date: Feb 2008
Bikes:
Posts: 772
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by umd View Post
4 power meters and no HR...
Nope...IMHO, HR is redundant if you've got a PM.

After all, HR isn't a measure of the effort/load, it's a measure of a response to the effort/load...and a highly damped one as well. Not to mention the myriad of other things that can adversely affect HR one way or the other.

It seems to me that power and PE together work pretty well without any other "measures"

That said, HR is better than nothing if you don't have a PM, at least for long, steady-state efforts.
tanhalt is offline   Reply With Quote
Old 12-03-08, 11:50 AM   #77
umd
Banned
 
umd's Avatar
 
Join Date: Sep 2005
Location: Santa Barbara, CA
Bikes: Specialized Tarmac SL2, Specialized Tarmac SL, Giant TCR Composite, Specialized StumpJumper Expert HT
Posts: 28,387
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by tanhalt View Post
Nope...IMHO, HR is redundant if you've got a PM.

After all, HR isn't a measure of the effort/load, it's a measure of a response to the effort/load...and a highly damped one as well. Not to mention the myriad of other things that can adversely affect HR one way or the other.

It seems to me that power and PE together work pretty well without any other "measures"

That said, HR is better than nothing if you don't have a PM, at least for long, steady-state efforts.
I was just giving you a hard time about the 4 PMs. Did you end up taking the Polar or the iBike off?
umd is offline   Reply With Quote
Old 12-03-08, 11:50 AM   #78
kudude
slow up hills
 
kudude's Avatar
 
Join Date: Mar 2006
Location: Seattle, WA
Bikes: Giant TCR, Redline CX, Ritchey Breakaway, Spec S-works epic
Posts: 4,931
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by waterrockets View Post
+1 to 5s power averaging.
I assume you choose to display on a 5s rolling average, but store data for each second. correct?
kudude is offline   Reply With Quote
Old 12-03-08, 12:48 PM   #79
ZeCanon
Writin' stuff
 
ZeCanon's Avatar
 
Join Date: Feb 2007
Location: Boulder, CO
Bikes:
Posts: 3,784
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
yep
ZeCanon is offline   Reply With Quote
Old 12-03-08, 01:10 PM   #80
tanhalt
Senior Member
 
tanhalt's Avatar
 
Join Date: Feb 2008
Bikes:
Posts: 772
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by kudude View Post
I assume you choose to display on a 5s rolling average, but store data for each second. correct?
Yes...the nice thing is that they are separately selectable.

Technically, the minimum sample rate on the PT is 1.26s and that's the best rate to use (if you aren't "memory limited" for the ride at hand) because selecting anything longer ends up in data being "thrown away" since the PT head unit will just store whatever happened in the last 1.26s before it stores...otherwise known as "downsampling"...not good
tanhalt is offline   Reply With Quote
Old 12-03-08, 01:13 PM   #81
bdcheung
Carpe Diem
 
bdcheung's Avatar
 
Join Date: Sep 2006
Location: MABRA
Bikes: 2007 CAAD9; 2014 CAADX; PedalForce CG1
Posts: 13,149
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
I still wear a HR strap, because i'm a data junkie. Plus when I preach about power meters to my teammates I can show them the graph and say "See how my HR goes up over the course of my 1-hr SST session, but power remains constant? If I was training based on HR alone, I'd be way under-doing it in the last half of the interval!"
__________________
"When you are chewing the bars at the business end of a 90 mile road race you really dont care what gear you have hanging from your bike so long as it works."
ΛΧΑ ΔΞ179 - 15% off your first Hammer Nutrition order!
bdcheung is offline   Reply With Quote
Old 12-03-08, 01:13 PM   #82
tanhalt
Senior Member
 
tanhalt's Avatar
 
Join Date: Feb 2008
Bikes:
Posts: 772
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by umd View Post
I was just giving you a hard time about the 4 PMs. Did you end up taking the Polar or the iBike off?
I know

The Polar is close to coming off since it's not telling me anything I don't know already about it, or about the other PMs...however, I promised one of the guys at Velocomp that I'd throw him a sample Polar output on a trainer to show how "flaky" it can be. The interest is if one could still use a Polar to "calibrate" an iBike for "trainer mode" despite the flakiness.... hmmm, maybe I'll do that at lunchtime today since I decided to take an "easy day"...then I can finally take that off.

My bike will suddenly be 1/2 lb lower weight
tanhalt is offline   Reply With Quote
Old 12-03-08, 01:19 PM   #83
kudude
slow up hills
 
kudude's Avatar
 
Join Date: Mar 2006
Location: Seattle, WA
Bikes: Giant TCR, Redline CX, Ritchey Breakaway, Spec S-works epic
Posts: 4,931
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by tanhalt View Post
Yes...the nice thing is that they are separately selectable.

Technically, the minimum sample rate on the PT is 1.26s and that's the best rate to use (if you aren't "memory limited" for the ride at hand) because selecting anything longer ends up in data being "thrown away" since the PT head unit will just store whatever happened in the last 1.26s before it stores...otherwise known as "downsampling"...not good
i prefer to downsample in post-processing. throwing away data should be a choice that you can reverse
kudude is offline   Reply With Quote
Old 12-03-08, 01:49 PM   #84
ridethecliche
Village Idiot
Thread Starter
 
Join Date: Jan 2007
Location: Bahstaaaaan
Bikes:
Posts: 20,241
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
I'm pretty sure I have my SRM set at 1 second intervals. I'll download data after every ride or two and since most of my rides aren't longer than 2-3 hours, the 6 hour setup works well.

I do need to go back and read the manual since I kept going into interval mode while trying to calibrate it yesterday. I couldn't get out of interval mode, so I just kept pressing buttons till something else happened haha.
ridethecliche is offline   Reply With Quote
Old 12-03-08, 10:37 PM   #85
challaday
Senior Member
 
Join Date: Sep 2008
Location: Just this side of insanity.
Bikes: Too many
Posts: 574
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
OK, I just got my powertap two days ago. I purchased the Allen & Coggan book about a month ago and read it cover-to-cover. So tonight I did the test from Chapter 3 on Functional Threshold Power, and I would like to make sure that I'm on the right track.

I followed their instructions religiously by taping a small guide on my handlebars while on my Kurt Kinetic trainer. I did the warmup as they proscribe, and then the 20 minute time trial. Oh, and if it matters, yesterday was my "rest" day and I did about an hour's worth of light spinning.

After downloading the data, the 20 minute time trial average power was 263.2 watts. According to the book, that means that 95% of that number, or 250.04 is my FTP. Since I weigh 155 pounds, or 70kg, that means my wkg value at FTP is 3.57

Does this sound like the right methodology and conclusion? Is doing the TT on the trainer good or bad?
challaday is offline   Reply With Quote
Old 12-03-08, 11:18 PM   #86
ridethecliche
Village Idiot
Thread Starter
 
Join Date: Jan 2007
Location: Bahstaaaaan
Bikes:
Posts: 20,241
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Quote:
Originally Posted by challaday View Post
OK, I just got my powertap two days ago. I purchased the Allen & Coggan book about a month ago and read it cover-to-cover. So tonight I did the test from Chapter 3 on Functional Threshold Power, and I would like to make sure that I'm on the right track.

I followed their instructions religiously by taping a small guide on my handlebars while on my Kurt Kinetic trainer. I did the warmup as they proscribe, and then the 20 minute time trial. Oh, and if it matters, yesterday was my "rest" day and I did about an hour's worth of light spinning.

After downloading the data, the 20 minute time trial average power was 263.2 watts. According to the book, that means that 95% of that number, or 250.04 is my FTP. Since I weigh 155 pounds, or 70kg, that means my wkg value at FTP is 3.57

Does this sound like the right methodology and conclusion? Is doing the TT on the trainer good or bad?
I think you're on the right track. If you do the test on the trainer, make sure you repeat it on the trainer everytime to exclude outside variables. Personally, I think testing on the trainer is the way to go.

Also, I would do a MAP test and see if your 20 minute interval falls in the range of 72-78% of MAP. Use it as a check.

Heh, your FTP and W/KG is right around mine. I'm ~68Kg.
ridethecliche is offline   Reply With Quote
Old 12-03-08, 11:19 PM   #87
waterrockets 
Making a kilometer blurry
 
waterrockets's Avatar
 
Join Date: May 2006
Location: Austin (near TX)
Bikes: rkwaki's porn collection
Posts: 26,130
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
95% is a very rough estimate.

On the trainer, you will likely be a little underpowered because of the inertial effects on your pedal stroke.

So, figure +/- 5% on the 95% number, and +/- 10% on the trainer effect, and you're at +/- 15%.

Just go train for a while and see what the numbers are showing you.
waterrockets is offline   Reply With Quote
Old 12-03-08, 11:26 PM   #88
ridethecliche
Village Idiot
Thread Starter
 
Join Date: Jan 2007
Location: Bahstaaaaan
Bikes:
Posts: 20,241
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Quote:
Originally Posted by waterrockets View Post
95% is a very rough estimate.

On the trainer, you will likely be a little underpowered because of the inertial effects on your pedal stroke.

So, figure +/- 5% on the 95% number, and +/- 10% on the trainer effect, and you're at +/- 15%.

Just go train for a while and see what the numbers are showing you.
Hm. I'm a little perplexed. I was under the impression that your seated W/Kg on a trainer would be higher since you're meeting resistance in every part of the pedal stroke and you can't 'con' your way out of your dead spot as easily as you can on the road.

When standing this isn't the case since you can't really move the bike under you and this generates power.
ridethecliche is offline   Reply With Quote
Old 12-03-08, 11:42 PM   #89
umd
Banned
 
umd's Avatar
 
Join Date: Sep 2005
Location: Santa Barbara, CA
Bikes: Specialized Tarmac SL2, Specialized Tarmac SL, Giant TCR Composite, Specialized StumpJumper Expert HT
Posts: 28,387
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by ridethecliche View Post
Hm. I'm a little perplexed. I was under the impression that your seated W/Kg on a trainer would be higher since you're meeting resistance in every part of the pedal stroke and you can't 'con' your way out of your dead spot as easily as you can on the road.

When standing this isn't the case since you can't really move the bike under you and this generates power.
I can't get as much power on the trainer, seated or otherwise.
umd is offline   Reply With Quote
Old 12-04-08, 12:16 AM   #90
ridethecliche
Village Idiot
Thread Starter
 
Join Date: Jan 2007
Location: Bahstaaaaan
Bikes:
Posts: 20,241
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Quote:
Originally Posted by umd View Post
I can't get as much power on the trainer, seated or otherwise.
Why do you think this is?

Is my logic reversed? Are we forced to spend more time in our deadspot while on the trainer?

This would reduce power during the dead spot, force more time there, and decrease average power.
ridethecliche is offline   Reply With Quote
Old 12-04-08, 12:20 AM   #91
ZeCanon
Writin' stuff
 
ZeCanon's Avatar
 
Join Date: Feb 2007
Location: Boulder, CO
Bikes:
Posts: 3,784
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
I would attribute it to having nothing else to think about but my legs hurting.

At least outside I have to use some brain power to not fall over.
ZeCanon is offline   Reply With Quote
Old 12-04-08, 01:01 AM   #92
ridethecliche
Village Idiot
Thread Starter
 
Join Date: Jan 2007
Location: Bahstaaaaan
Bikes:
Posts: 20,241
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Quote:
Originally Posted by ZeCanon View Post
I would attribute it to having nothing else to think about but my legs hurting.

At least outside I have to use some brain power to not fall over.
LOL!

I watch movies or blast movies while on the trainer. I actually don't mind riding the trainer while doing that. 1 hour max (with intervals) if just listening to music. I can go for 1.5+ hours if I'm watching a race, show, movie, whatever.
ridethecliche is offline   Reply With Quote
Old 12-04-08, 01:12 AM   #93
waterrockets 
Making a kilometer blurry
 
waterrockets's Avatar
 
Join Date: May 2006
Location: Austin (near TX)
Bikes: rkwaki's porn collection
Posts: 26,130
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
I think it has to do with the inertial differences between the road and the trainer. If you stop pedaling on the trainer, it doesn't take long to come to a complete stop. On the road, it takes a really long time. So, on the trainer, the dead part of your stroke (with reduced power) is going to decelerate more than on the road.

This means that you're spending energy accelerating the wheel more with each pedal stroke, which means that your normal applied torque will be multiplied by a lower angular velocity on the crank or the wheel, until you get back up to speed during the stroke. Lower angular velocity means less power.
waterrockets is offline   Reply With Quote
Old 12-04-08, 01:34 AM   #94
ridethecliche
Village Idiot
Thread Starter
 
Join Date: Jan 2007
Location: Bahstaaaaan
Bikes:
Posts: 20,241
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Quote:
Originally Posted by waterrockets View Post
I think it has to do with the inertial differences between the road and the trainer. If you stop pedaling on the trainer, it doesn't take long to come to a complete stop. On the road, it takes a really long time. So, on the trainer, the dead part of your stroke (with reduced power) is going to decelerate more than on the road.

This means that you're spending energy accelerating the wheel more with each pedal stroke, which means that your normal applied torque will be multiplied by a lower angular velocity on the crank or the wheel, until you get back up to speed during the stroke. Lower angular velocity means less power.
That's basically what I was trying to say less elegantly. Thanks WR!
ridethecliche is offline   Reply With Quote
Old 12-04-08, 03:53 AM   #95
mista_chewey
newbie rider
 
Join Date: Aug 2007
Location: Houston, TX
Bikes:
Posts: 481
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
so basically those ftp tests are just testing your power in a 20minute time frame?
gotta go try that....
mista_chewey is offline   Reply With Quote
Old 12-04-08, 06:48 AM   #96
ljrichar
bf is my facebook.
 
ljrichar's Avatar
 
Join Date: Mar 2006
Location: Greensboro, NC
Bikes:
Posts: 1,156
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by mista_chewey View Post
so basically those ftp tests are just testing your power in a 20minute time frame?
gotta go try that....
Not exactly. FTP is the power you can hold for a 60min time trial. That is why they were taking 95% of the 20min time as an estimate of FTP.
ljrichar is offline   Reply With Quote
Old 12-04-08, 07:30 AM   #97
sgrundy
I am the cheese
 
sgrundy's Avatar
 
Join Date: Jul 2007
Location: Cycling Purgatory (Brooklyn, NY)
Bikes:
Posts: 236
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by waterrockets View Post
I think it has to do with the inertial differences between the road and the trainer. If you stop pedaling on the trainer, it doesn't take long to come to a complete stop. On the road, it takes a really long time. So, on the trainer, the dead part of your stroke (with reduced power) is going to decelerate more than on the road.

This means that you're spending energy accelerating the wheel more with each pedal stroke, which means that your normal applied torque will be multiplied by a lower angular velocity on the crank or the wheel, until you get back up to speed during the stroke. Lower angular velocity means less power.
That's part of it. The other part is that it can be hard to stay cool indoors. If you have a trainer with a massive flywheel and a huge fan nearby you might actually be able to exceed the power that you can generate outdoors. However, I've read that after a few weeks of adapting to the trainer indoor and outdoor power numbers start to converge, so if you're on the trainer a lot there might not be a significant difference.
sgrundy is offline   Reply With Quote
Old 12-04-08, 10:12 AM   #98
waterrockets 
Making a kilometer blurry
 
waterrockets's Avatar
 
Join Date: May 2006
Location: Austin (near TX)
Bikes: rkwaki's porn collection
Posts: 26,130
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Quote:
Originally Posted by sgrundy View Post
That's part of it. The other part is that it can be hard to stay cool indoors. If you have a trainer with a massive flywheel and a huge fan nearby you might actually be able to exceed the power that you can generate outdoors. However, I've read that after a few weeks of adapting to the trainer indoor and outdoor power numbers start to converge, so if you're on the trainer a lot there might not be a significant difference.
yep
waterrockets is offline   Reply With Quote
Old 12-04-08, 10:14 AM   #99
Psimet2001 
I eat carbide.
 
Psimet2001's Avatar
 
Join Date: Jan 2006
Location: Elgin, IL
Bikes: Lots. Van Dessel and Squid Dealer
Posts: 19,744
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 22 Post(s)
Watt?
Psimet2001 is offline   Reply With Quote
Old 12-04-08, 10:39 AM   #100
fuzzthebee
bzzzz
 
fuzzthebee's Avatar
 
Join Date: Feb 2005
Bikes:
Posts: 360
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by challaday View Post
OK, I just got my powertap two days ago. I purchased the Allen & Coggan book about a month ago and read it cover-to-cover. So tonight I did the test from Chapter 3 on Functional Threshold Power, and I would like to make sure that I'm on the right track.

I followed their instructions religiously by taping a small guide on my handlebars while on my Kurt Kinetic trainer. I did the warmup as they proscribe, and then the 20 minute time trial. Oh, and if it matters, yesterday was my "rest" day and I did about an hour's worth of light spinning.

After downloading the data, the 20 minute time trial average power was 263.2 watts. According to the book, that means that 95% of that number, or 250.04 is my FTP. Since I weigh 155 pounds, or 70kg, that means my wkg value at FTP is 3.57

Does this sound like the right methodology and conclusion? Is doing the TT on the trainer good or bad?
You might want to round off your power numbers. Power meters are not that precise, and niether is estimating FTP.
fuzzthebee is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -6. The time now is 05:17 PM.