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


Go Back   > >

Road Cycling “It is by riding a bicycle that you learn the contours of a country best, since you have to sweat up the hills and coast down them. Thus you remember them as they actually are, while in a motor car only a high hill impresses you, and you have no such accurate remembrance of country you have driven through as you gain by riding a bicycle.” -- Ernest Hemingway

User Tag List

Reply
 
Thread Tools Search this Thread
Old 02-03-07, 08:24 AM   #76
DrPete 
Dirt-riding heretic
 
DrPete's Avatar
 
Join Date: Aug 2005
Location: Gig Harbor, WA
Bikes: Lynskey R230/Red, Blue Triad SL/Red, Cannondale Scalpel 3/X9
Posts: 17,415
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
I guess I'm just not understanding it. If the iBike uses speed/cadence/grade/airflow to calculate power output I don't see how it would be consistent in a paceline, unless there's some factor in the calculation that allows for changes in wind resistance.

And if we all just had $3400 to spend on our SRMs, all of this would be a moot point and we could actually measure power directly.
__________________
"Unless he was racing there was no way he could match my speed."
DrPete is offline   Reply With Quote
Old 02-03-07, 08:26 AM   #77
bdcheung
Carpe Diem
 
bdcheung's Avatar
 
Join Date: Sep 2006
Location: MABRA
Bikes: 2007 CAAD9; 2014 CAADX; PedalForce CG1
Posts: 13,147
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Too much hassle. My PT tells me my watts no matter the conditions.
__________________
"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 02-03-07, 08:28 AM   #78
NoRacer
Isaias
 
NoRacer's Avatar
 
Join Date: Sep 2005
Location: Essex, MD
Bikes: Ridley X-Fire (carbon, white)
Posts: 5,179
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Quote:
Originally Posted by DrPete
...unless there's some factor in the calculation that allows for changes in wind resistance.
Exactly... it's the Aero Drag parameter that you acquire during a Coast Down calibration. Because it has a wind pressure sensor in front of the unit, similar to the wind sensor used by aircraft to get their wind speed, the iBike can sense when there is wind or not and adjust the power calculations for the occurance or lack thereof.
NoRacer is offline   Reply With Quote
Old 02-03-07, 08:37 AM   #79
NoRacer
Isaias
 
NoRacer's Avatar
 
Join Date: Sep 2005
Location: Essex, MD
Bikes: Ridley X-Fire (carbon, white)
Posts: 5,179
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
BTW, not to deflect away from the iBike, but have you seen this?

http://www.microsporttech.com/
NoRacer is offline   Reply With Quote
Old 02-03-07, 08:40 AM   #80
bdcheung
Carpe Diem
 
bdcheung's Avatar
 
Join Date: Sep 2006
Location: MABRA
Bikes: 2007 CAAD9; 2014 CAADX; PedalForce CG1
Posts: 13,147
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Quote:
± 5% Seated compares with torque based devices!
The thing becomes inaccurate when you stand up / hammer.
__________________
"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 02-03-07, 08:45 AM   #81
jrennie
Race to train
 
jrennie's Avatar
 
Join Date: May 2005
Location: suffering on the back
Bikes:
Posts: 3,115
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
^^^^^^^^^^^^^^^^^^
thats a new one, power meter from your shoe. DrPete, I just sold my 725x on "the bay" for 3 dollars less than I paid for it and picked up a PT pro for a good price, so for the same amout of money as it would have cost for the power upgrade and I got a PT. Maybe an option for you. I was a little nervous as to the polar power given some riders reviews locally and the amout of used that seem to be floating around. If its that good the why do people keep getting rid of it.
jrennie is offline   Reply With Quote
Old 02-03-07, 08:48 AM   #82
NoRacer
Isaias
 
NoRacer's Avatar
 
Join Date: Sep 2005
Location: Essex, MD
Bikes: Ridley X-Fire (carbon, white)
Posts: 5,179
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Quote:
Originally Posted by bdcheung
The thing becomes inaccurate when you stand up / hammer.
Thus it begins.

I'd like to keep going, but it's time to get on the rollers. Fire away.
NoRacer is offline   Reply With Quote
Old 02-03-07, 03:28 PM   #83
DrPete 
Dirt-riding heretic
 
DrPete's Avatar
 
Join Date: Aug 2005
Location: Gig Harbor, WA
Bikes: Lynskey R230/Red, Blue Triad SL/Red, Cannondale Scalpel 3/X9
Posts: 17,415
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
I did my first Power testing today, and I'm a mediocre Cat 4 according to the Friel/Coggan power tables... guess the Polar is pretty accurate

5 min power: 373W (4.02W/kg), FTP 301W (3.26W/kg)

If it weren't for all those damned kg I have to divide by I'd be in pretty good shape. But I'm getting rid of some of those as we speak. I'm encouraged, though, because those numbers are with a mild hangover and going into a recovery week. All in all pretty satisfying since I have yet to start my build period.
__________________
"Unless he was racing there was no way he could match my speed."
DrPete is offline   Reply With Quote
Old 02-03-07, 03:41 PM   #84
bdcheung
Carpe Diem
 
bdcheung's Avatar
 
Join Date: Sep 2006
Location: MABRA
Bikes: 2007 CAAD9; 2014 CAADX; PedalForce CG1
Posts: 13,147
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Those are some good numbers! I wish I could put out 4+w/kg... My 5min max is 3.63w/kg (245 watts) and 20min is 2.76w/kg. Though I haven't done a real 20min test yet.
__________________
"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 02-03-07, 03:44 PM   #85
NoRacer
Isaias
 
NoRacer's Avatar
 
Join Date: Sep 2005
Location: Essex, MD
Bikes: Ridley X-Fire (carbon, white)
Posts: 5,179
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Quote:
Originally Posted by DrPete
I did my first Power testing today, and I'm a mediocre Cat 4 according to the Friel/Coggan power tables... guess the Polar is pretty accurate

5 min power: 373W (4.02W/kg), FTP 301W (3.26W/kg)

If it weren't for all those damned kg I have to divide by I'd be in pretty good shape. But I'm getting rid of some of those as we speak. I'm encouraged, though, because those numbers are with a mild hangover and going into a recovery week. All in all pretty satisfying since I have yet to start my build period.
We need to ride together sometime, Doc.
NoRacer is offline   Reply With Quote
Old 02-03-07, 03:46 PM   #86
DrPete 
Dirt-riding heretic
 
DrPete's Avatar
 
Join Date: Aug 2005
Location: Gig Harbor, WA
Bikes: Lynskey R230/Red, Blue Triad SL/Red, Cannondale Scalpel 3/X9
Posts: 17,415
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by NoRacer
We need to ride together sometime, Doc.
Funny that invitation only came out after I posted my stellar power data.
__________________
"Unless he was racing there was no way he could match my speed."
DrPete is offline   Reply With Quote
Old 02-03-07, 03:55 PM   #87
NoRacer
Isaias
 
NoRacer's Avatar
 
Join Date: Sep 2005
Location: Essex, MD
Bikes: Ridley X-Fire (carbon, white)
Posts: 5,179
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Quote:
Originally Posted by DrPete
Funny that invitation only came out after I posted my stellar power data.
Well, you know what I'm using, now, and here's what I got from just ride data:

NoRacer is offline   Reply With Quote
Old 02-03-07, 03:58 PM   #88
bdcheung
Carpe Diem
 
bdcheung's Avatar
 
Join Date: Sep 2006
Location: MABRA
Bikes: 2007 CAAD9; 2014 CAADX; PedalForce CG1
Posts: 13,147
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
holy. ****.
__________________
"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 02-03-07, 04:01 PM   #89
NoRacer
Isaias
 
NoRacer's Avatar
 
Join Date: Sep 2005
Location: Essex, MD
Bikes: Ridley X-Fire (carbon, white)
Posts: 5,179
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Quote:
Originally Posted by bdcheung
holy. ****.
All it says is that I could, if I raced, be a CAT 5 with inclination to CAT 4. But, I'm NoRacer, so...
NoRacer is offline   Reply With Quote
Old 02-03-07, 04:04 PM   #90
bdcheung
Carpe Diem
 
bdcheung's Avatar
 
Join Date: Sep 2006
Location: MABRA
Bikes: 2007 CAAD9; 2014 CAADX; PedalForce CG1
Posts: 13,147
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
So if I want to increase my w/kg without losing weight (i'm already 5'10", 150lbs), do I just need to ride more? Or incorporate weight training more heavily into my routine?
__________________
"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 02-03-07, 04:07 PM   #91
DrPete 
Dirt-riding heretic
 
DrPete's Avatar
 
Join Date: Aug 2005
Location: Gig Harbor, WA
Bikes: Lynskey R230/Red, Blue Triad SL/Red, Cannondale Scalpel 3/X9
Posts: 17,415
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by bdcheung
So if I want to increase my w/kg without losing weight (i'm already 5'10", 150lbs), do I just need to ride more? Or incorporate weight training more heavily into my routine?
Well, looking at my handy new book , I would say that it depends on which area you want to work on. Training geared toward raising W/kg at FTP will make you a good time trialist, but will likely not do much for the 5sec and 1min numbers that are so important for the crits.
__________________
"Unless he was racing there was no way he could match my speed."
DrPete is offline   Reply With Quote
Old 02-03-07, 04:14 PM   #92
NoRacer
Isaias
 
NoRacer's Avatar
 
Join Date: Sep 2005
Location: Essex, MD
Bikes: Ridley X-Fire (carbon, white)
Posts: 5,179
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Quote:
Originally Posted by DrPete
Well, looking at my handy new book , I would say that it depends on which area you want to work on. Training geared toward raising W/kg at FTP will make you a good time trialist, but will likely not do much for the 5sec and 1min numbers that are so important for the crits.
Here's what I'm concentrating on now... base training:



BD, increasing FTP should have an affect on all of your numbers, but muscle type, borne out from doing a power profile, will show whether your are inclined to be a "sprinter" or "road racer" or something in between.
NoRacer is offline   Reply With Quote
Old 02-03-07, 04:16 PM   #93
bdcheung
Carpe Diem
 
bdcheung's Avatar
 
Join Date: Sep 2006
Location: MABRA
Bikes: 2007 CAAD9; 2014 CAADX; PedalForce CG1
Posts: 13,147
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
My power profile has my 5sec listed at 14.74w/kg and my 1min at 7.22w/kg. Everything but my FT power is pretty solidly in the Cat5 range, so I seem to be an all-arounder. I think I need to do more work riding at, or right below, my FTP.
__________________
"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 02-03-07, 04:46 PM   #94
NomadVW 
部門ニ/自転車オタク
 
NomadVW's Avatar
 
Join Date: Dec 2005
Location: Yuma, AZ
Bikes: 2005 Specialized Roubaix Elite, 2005 Specialized FSR XC Comp, 2008 Blue T16, 2009 Blue RC8, Fetish Cycles Road Bike
Posts: 3,172
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Everything you do increases overall w/kg, technically. Weight training won't help your long distance power. For that, you simply need to ride more, and smarter. There's so much debate on the sequence of training to get the best increase in FTP that it's impossible for me to figure out, so I got a coach. I'm now posting my best 5 minute/FTP numbers ever and was pleasantly pleased to put the hurt locker on our Saturday morning hammerfest yesterday.

Dr. Pete! When'd you get a powermeter?! What are you using. I can't find the post that says you got one and inquiring minds want to know Good numbers over there in that other thread.
__________________
Envision, Energize, Enable
NomadVW is offline   Reply With Quote
Old 02-03-07, 04:50 PM   #95
bdcheung
Carpe Diem
 
bdcheung's Avatar
 
Join Date: Sep 2006
Location: MABRA
Bikes: 2007 CAAD9; 2014 CAADX; PedalForce CG1
Posts: 13,147
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Nomad: you're in the thread, silly!
__________________
"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 02-03-07, 04:52 PM   #96
DrPete 
Dirt-riding heretic
 
DrPete's Avatar
 
Join Date: Aug 2005
Location: Gig Harbor, WA
Bikes: Lynskey R230/Red, Blue Triad SL/Red, Cannondale Scalpel 3/X9
Posts: 17,415
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by NomadVW
Dr. Pete! When'd you get a powermeter?! What are you using. I can't find the post that says you got one and inquiring minds want to know Good numbers over there in that other thread.
I got the Polar sensor a few days ago--it's earlier in this thread. If you're very anal-retentive about the installation it seems to give some good numbers. My only gripe is that I may never get good 5sec power measurements because it can miss quick bursts, but all in all it seems to give good data for anything longer than 15sec or so.

And saving for a Powertap has already begun. My grand plan for my 2 years of professional hell is to have a beater bike in my office on a trainer and switch the Powertap wheel between bikes. But that's a ways down the road. In the mean time, the Polar seems to be doing a decent job.
__________________
"Unless he was racing there was no way he could match my speed."
DrPete is offline   Reply With Quote
Old 02-03-07, 04:52 PM   #97
DrPete 
Dirt-riding heretic
 
DrPete's Avatar
 
Join Date: Aug 2005
Location: Gig Harbor, WA
Bikes: Lynskey R230/Red, Blue Triad SL/Red, Cannondale Scalpel 3/X9
Posts: 17,415
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by bdcheung
Nomad: you're in the thread, silly!
I cross-posted to the "training status" thread too.
__________________
"Unless he was racing there was no way he could match my speed."
DrPete is offline   Reply With Quote
Old 02-03-07, 04:53 PM   #98
bdcheung
Carpe Diem
 
bdcheung's Avatar
 
Join Date: Sep 2006
Location: MABRA
Bikes: 2007 CAAD9; 2014 CAADX; PedalForce CG1
Posts: 13,147
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Quote:
Originally Posted by DrPete
My grand plan for my 2 years of professional hell is to have a beater bike in my office on a trainer and switch the Powertap wheel between bikes.
Wanna buy my Denali?
__________________
"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 02-03-07, 09:45 PM   #99
NomadVW 
部門ニ/自転車オタク
 
NomadVW's Avatar
 
Join Date: Dec 2005
Location: Yuma, AZ
Bikes: 2005 Specialized Roubaix Elite, 2005 Specialized FSR XC Comp, 2008 Blue T16, 2009 Blue RC8, Fetish Cycles Road Bike
Posts: 3,172
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by DrPete
I got the Polar sensor a few days ago--it's earlier in this thread. If you're very anal-retentive about the installation it seems to give some good numbers.
If it makes you feel better about the Polar sensor - one of our local riders is a sponsored Semi-pro MTB racer in Japan for Specialized. The last time I saw him he had the polar sensor on his Specialized S-works road bike and seemed to be pretty happy with it. I can safely say that he wasn't weak as a result of using the polar.

Look forward to hearing your improvements now that you've begun to make the switch.

VW
__________________
Envision, Energize, Enable
NomadVW is offline   Reply With Quote
Old 02-05-07, 09:53 AM   #100
eandmwilson
Senior Member
 
eandmwilson's Avatar
 
Join Date: Aug 2005
Location: All your base (miles) are belong to us
Bikes:
Posts: 606
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by 2thamaxx
The Polar is definitely the cheapest option but definitely not accurate.
Yes it is consistent as it's fault tolerance.

I've read the following information about the polar. (translated)
“The difference between this one and the others like SRM is that the polar is measuring the frequency of the chain.
By using an induction (magnet) the polar is collecting this information.
Together with the length and weight of the chain it calculates the power.
This data input needs to be precisely as possible.
The problem is that during the use of the bike the length and weight of the chain will change and it will get dirty.
Plus shifting gear will change the direction of the chain over the magnet.”
(frequency change)

So if you want accurate information don't need to by the Polar.
But if you want the cheapest then you go for the Polar.
And we all want that J
For such small angles, the frequency change will not be dependent on the direction over the magnet, but the length of the chain between the chainring and the cog. If that distance is long, the angle created by shifting to extremes of the cog are limited. On my bike it would represent about 5 degrees on either side of the middle cog, especially since I don't use one of the cogs at all. As for length, chain stretch during a ride has to be negligible. Over a 1000 miles, you mike want to check, but from ride to ride any stretch will be in the margins.

The real potential issue for accuracy is chain weight. Gunk that chain up, and its vibrational frequency will go all to hooey.

What always bothers me about these sorts of comments is people feel the need to throw in every cat and dog as to why something is great or sucks. It would be substantially more helpful to only include the relevant issues, like chain weight impacting vibrational frequency, than all the other red herrings.

I am, BTW, in no way claiming the Polar is the most accurate option.

Pete: any pics yet?
eandmwilson 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 06:03 AM.