I used to blow up tanks for a living. I kind of miss my TOW missle launcher.
well once you get a power meter you realize you don’t have to put out very many watts to go fast on a flat surface. but you also realize that you need tremendous amounts of watts to go up an slight angle at the same speed.
Funny…my boss and I just had a conversation on guestimates at our engineering firm. Right now I work on multi-million dollar projects that begin with exactly this kind of guess work.
You mean you can’t tell me if on a flat road on a windless day that you can’t nail down a range that increasing from 200-250 watts will put you in? Is that a 1 mph increase or closer to a 30 mph increase?
yup, I am an engineer as well and you are right… projects start with educated guesses. and then iterate with data and analysis.
besides the point…
anyway. here is what is going to happen. you have determined that 25w will show you a 1mph increase. and one day you will go out and “test” on a windless flat course. But will you check air temp/density? will you check wind speed/direction/peak? will you keep records and compare one day to the other accurately? most won’t.
you should remember from engineering 101 that GIGO.
the $ arguement is totally bs with most around here having very nice bike(s) claiming no funds for a powermeter.
I don’t get excited for the $8k p3c and no powermeter. but the guy on the used $150 leader w/ 105 and a powertap… he’s my man/gal.
even the ibike is a better tool than your “testing” method.
g
Barry, I have been training w/ an Ergomo for the last ~ 9 months → Gets off of soap box.
I weigh ~ 160 and my bike wieghs ~ 19 lbs. Here’s info from a few races I’ve done this year. Hopefully this helps you with your estimation.
Half IM in May (on flat course): NP = 235 watts for average of 21.2 mph
Olympic in May (on hilly course): NP = 275 watts for average of 20.8 mph
Olympic in July (on rolling course): NP = 285 watts for average of 23.8 mph
Sprint in July (on relatively flat course): NP = 302 watts for average of 24.7 mph
** How do you correlate power to speed?? **
Easy!
More is MORE!!!
Next?
Barry, I have been training w/ an Ergomo for the last ~ 9 months → Gets off of soap box.
I weigh ~ 160 and my bike wieghs ~ 19 lbs. Here’s info from a few races I’ve done this year. Hopefully this helps you with your estimation.
Half IM in May (on flat course): NP = 235 watts for average of 21.2 mph
Olympic in May (on hilly course): NP = 275 watts for average of 20.8 mph
Olympic in July (on rolling course): NP = 285 watts for average of 23.8 mph
Sprint in July (on relatively flat course): NP = 302 watts for average of 24.7 mph
Holy good lord i sure hope its not calibrated with those wattages or you have the postition of a mountain biker.
I did St. Anthonys at 24.1 on 230 watts. and a 7.5 mile time trial at 26.1 at 285 watts.
Grant
I used to blow up tanks for a living. I kind of miss my TOW missle launcher.
Kilo natioyes that is fun stuff
I liked the bigger missles to
much more fun than a m16 and a few clips
dirt
I don’t get excited for the $8k p3c and no powermeter. but the guy on the used $150 leader w/ 105 and a powertap… he’s my man/gal.
Sounds like MuffinTop, except he bought his Leader new.
Quote:
" I weigh ~ 160 and my bike wieghs ~ 19 lbs. Here’s info from a few races I’ve done this year. Hopefully this helps you with your estimation.
Half IM in May (on flat course): NP = 235 watts for average of 21.2 mph
Olympic in May (on hilly course): NP = 275 watts for average of 20.8 mph
Olympic in July (on rolling course): NP = 285 watts for average of 23.8 mph
Sprint in July (on relatively flat course): NP = 302 watts for average of 24.7 mph
Holy good lord i sure hope its not calibrated with those wattages or you have the postition of a mountain biker.
I did St. Anthonys at 24.1 on 230 watts. and a 7.5 mile time trial at 26.1 at 285 watts.
Hey Grant, that’s some interesting perspective to see your power #'s. From what I understand, there are many things that factor into how much speed each individual gets out of a given wattage. FWIW, here’s a photo of my position (taken from the race where my NP was 285 for 23.8 mph over rolling hills) - my position could probably be dialed in a bit more, but I’m definitely not sitting up like a mountain biker 
http://gallery.triduo.com/p/artistic_bike_colonial_beach_triathlon_2007/1444-0562-9826-bdg56
Also note that my power #'s were expressed in normalized watts - the actual average wattages were at least 10 watts lower depending on how hilly the course was.
I’m interested in knowing what you and your bike weigh and what kind of power meter you are using. Seems like your power #'s are quite low for the speeds you are going - I would speculate that you and your bike weigh a bit less than my set up, and you’re probably a bit more aero. Seems like I saw someone report that Stadler and Faris each averaged somewhere in the neghborhood of 260+ watts to ride ~24 mph @ Hawaii the last couple of years - so it seems like 275 watts (285 NP) for me to average 23.8 mph over rolling hills (and I am positive my bike and I weigh more and are less aero than those guys) does not seem that out of whack. Am I being crazy?
Those numbers seem wildly inconsistent. 275W for 20.8mph?!?!?! I ride about 165W for 20mph, and ~25.5mph on 275W. Ouch! Unless you were climbing up and down L Alpe de Huez this seems kinda odd. The others seem a bit high in power vs speed, I did a half earlier in May also this year on 225W at 22.6mph. I probably have slightly better aerodynamics, but I’ve spent a lot of time tweaking this.
Those numbers seem wildly inconsistent. 275W for 20.8mph?!?!?! I ride about 165W for 20mph, and ~25.5mph on 275W. Ouch! Unless you were climbing up and down L Alpe de Huez this seems kinda odd. The others seem a bit high in power vs speed, I did a half earlier in May also this year on 225W at 22.6mph. I probably have slightly better aerodynamics, but I’ve spent a lot of time tweaking this.
275W was normalized wattage. Actual average was ~ 260 Watts. Definitely not Alp de Huez, but it was a very hilly course (Columbia Triathlon in Maryland). I know a couple of guys who have FT’s north of 310 watts whose bike splits at that race were in the 22.5 - 23 mph range (and they were riding hard), so 260 watts for ~ 21 mph doesn’t seem that crazy to me. It’s just a hilly as hell course.
I’m not that concerned about how the wattages from my power meter calibrate with those produced by the powermeters of other riders who may be lighter riders, with lighter bikes, with better aerodynamics than me. My #'s could be off compared to those of others, but I don’t think they are off by that much, and they are consistent over the course of my training and racing, so I have a reliable baseline to measure my training protocol and my race pacing against. I got the Ergomo because I wanted to train w/ power in hopes of getting faster. Since I began training with it, I have gotten considerably faster. That’s all I need to know about the wattage numbers that my device reports back to me.
I don’t get excited for the $8k p3c and no powermeter. but the guy on the used $150 leader w/ 105 and a powertap… he’s my man/gal.
g
You rang?
I think the point that many people are trying to make is:
You already know this but just remember that savvy engineers don’t make guestimates using/comparing variables that they know are meaningless to the end result. Your end result is to map out some performance goals for some of your workouts. As Cramer implied, guestimating power to speed is a fairly meaningless process when your goal is performance improvement in training.
Thanks, Chris
Am I being crazy?
No, but looking at your position and comparing to Grant’s, it’s pretty obvious to see why the differences.
Here’s a WAG:
no aero-helmet + not low enough + arms pointing down = 20watts
your goal is performance improvement in training.
Funny, I thought the goal was performance improvement in racing.
your goal is performance improvement in training.
Funny, I thought the goal was performance improvement in racing.
Then I suggest you read his original post. Here’s a direct quote:
“I just want to be able to map some performance goals with some of my workouts.”
Hope that helps you understand why I said, “… performance improvement in training.”
Thanks, Chris
Am I being crazy?
No, but looking at your position and comparing to Grant’s, it’s pretty obvious to see why the differences.
Here’s a WAG:
no aero-helmet + not low enough + arms pointing down = 20watts
Thanks Paulo - that’s some good constructuve position feedback. I am working to get lower - I just got a new adjustable stem and some Vision R Bends to get me considerably lower than I was - sounds like the hands/arms pointing down are not helping my aerodynamics, though. Now that I’m getting comfortable in my current position, I will probably try to drop the adjustable stem a few more mm’s. Sounds like I need to get an aero helmet, too… appreciate the tips!
You already know this but just remember that savvy engineers don’t make guestimates using/comparing variables that they know are meaningless to the end result. Your end result is to map out some performance goals for some of your workouts. As Cramer implied, guestimating power to speed is a fairly meaningless process when your goal is performance improvement in training.
Meaningless is a relative term. Latin is meaningelss if you don’t speak the language. I got the answers I was looking for.
anyway. here is what is going to happen. you have determined that 25w will show you a 1mph increase. and one day you will go out and “test” on a windless flat course. But will you check air temp/density? will you check wind speed/direction/peak? will you keep records and compare one day to the other accurately? most won’t.
Actually I have no intention of doing any of that. I’m not writting a research paper. I just wanted to get a ballpark figure so that I’ll have some idea what wattage increases mean so that I can adjust my training accordingly. Now quit being such a nerd!
anyway. here is what is going to happen. you have determined that 25w will show you a 1mph increase. and one day you will go out and “test” on a windless flat course. But will you check air temp/density? will you check wind speed/direction/peak? will you keep records and compare one day to the other accurately? most won’t.
Actually I have no intention of doing any of that. I’m not writting a research paper. I just wanted to get a ballpark figure so that I’ll have some idea what wattage increases mean so that I can adjust my training accordingly. Now quit being such a nerd!
my point is without those “nerdy” calculations, you WON’T have an idea of how wattage has increased. hence why they make powermeters.
g