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-   -   Just started training with Power? Post your questions/comments here! (http://www.bikeforums.net/33-road-bike-racing/488667-just-started-training-power-post-your-questions-comments-here.html)

mattm 03-05-09 05:58 PM

Quote:

Originally Posted by pcates (Post 8475839)
sorry to change the subject, but i was curious about what sort of TSS numbers one should be aiming for in terms of hard days, easy days and weekly?

my understanding is that a TSS of 100 is equivalent to an all-out 40k TT.

found a little guideline here:

The following scale can be used as an approximate guide:

Less than 150 - low (recovery generally complete by following day)
150-300 - medium (some residual fatigue may be present the next day, but gone by 2nd day)
300-450 - high (some residual fatigue may be present even after 2 days)
Greater than 450 - very high (residual fatigue lasting several days likely)

umd 03-05-09 06:03 PM

Quote:

Originally Posted by pcates (Post 8475839)
sorry to change the subject, but i was curious about what sort of TSS numbers one should be aiming for in terms of hard days, easy days and weekly?

There is no set amount to "shoot for". What works for one person may be way too high for another. TSS is a combination of your volume and intensity so it's going to be affected by how much riding you are doing, and how well conditioned you are to maintain intensity over that duration. Rather than thinking in terms of a TSS number, you can think about your ATL and CTL and build your CTL by increasing your ATL for a few weeks, then back off and recover, build, recover, repeat. If you try to increase too quickly shooting for a number you are likely to just burn yourself out or not be able to do the appropriate intensity for your workouts.

tombailey 03-06-09 10:46 AM

What difference does the 12mm axle of the Pro+ vs. the 15mm axle of the SL+ make? Are there any other diffferences besides weight/material?

Thanks,
Tom

esammuli 03-06-09 11:00 AM

The 15mm axle is stiffer.

tombailey 03-06-09 11:01 AM

Quote:

Originally Posted by esammuli (Post 8479905)
The 15mm axle is stiffer.

Is it stronger?

esammuli 03-06-09 11:11 AM

Possibly, but I'm not positive on that one. An interesting tidbit that most people don't realize is that for several years many pro's were using custom carbon axles due to the lack of stiffness of the standard 12mm axle. The increase in axle size also lets CycleOps use a bearing with a larger diameter inside race which apparently increases the lifespan of the bearing.

edit: I know the guy who did most of the design work for the hub internals for new generation SL+ and SLC+. When I was spec'ing a new custom Pro+ build from him he strongly recommended 'upgrading' from the 12mm alloy axle to the steel mtb axle. He's a smart guy with an extremely good reputation so I took his advise.

tombailey 03-06-09 11:15 AM

Thank-you

Gluteus 03-07-09 03:01 PM

I just recently started using a PT.
This is recovery ride (trainer, same resistance, 60'). I notice that after about 5 minutes I sustain a stable power, but the recorded speed drops steadily until about 30' when it becomes stable. I have seen the same pattern 3 times.
The questions is: at the same power output, with the same resistance, why would the speed drop ?

http://i443.photobucket.com/albums/q...forums/3-4.jpg

waterrockets 03-07-09 03:09 PM

It's not the same resistance. The trainer is turning all of the energy from your tire into heat, sound, and air motion. The heat inside the resistance unit is probably causing parts to expand, which will increase the resistance.

Gluteus 03-07-09 03:40 PM

Quote:

Originally Posted by waterrockets (Post 8486391)
It's not the same resistance. The trainer is turning all of the energy from your tire into heat, sound, and air motion. The heat inside the resistance unit is probably causing parts to expand, which will increase the resistance.

Ahh! Thanks.

ijgoodwin 03-17-09 07:40 PM

Question for smarter PowerTap users than me. I have a power file from a ride where I didn't realize that I needed to zero the torque, so for about the first 80-90% of the file, the torque reading is 1.13 above where it should be. So, I can subtract 1.13 from the torque values to fix those, but what do I do to fix the power data, as the power values where torque should be zero are not consistent? Do I use the average, max, or some other level of the power values where torque will be zero?

umd 03-17-09 07:44 PM

You multiply the torque x wheel rpm to get new power values.

ijgoodwin 03-17-09 07:46 PM

Quote:

Originally Posted by umd (Post 8549162)
You multiply the torque x wheel rpm to get new power values.

Good deal! thanks :thumb:

irish pat 03-17-09 08:59 PM

For those of you that use golden cheetah or training peaks, what are the advantages over usung poweragent?

ridethecliche 03-17-09 09:32 PM

Prettier graphs?

waterrockets 03-17-09 10:16 PM

Quote:

Originally Posted by umd (Post 8549162)
You multiply the torque x wheel rpm to get new power values.

Close, but power = torque * angular speed (not rpm). In MKS units, angular speed is radians/second.

In the CSV, just set up the following cells:

Code:

m/s                    circumference    rot/s                rad/s            Watts
(kmph*1000)/(60*60)    2.096        (m/s)/(circumference)    (rot/s)*2*3.14159    torque*rad/s

...or, paste this in row 2 of the .csv (to the right of the last column), and extend it down:
Code:

=B2*((C2*1000)/(60*60)/2.096)*2*3.14159
B2 is torque, and C2 is km/h, and 2.096 is your circumference on the head unit x 1000

ijgoodwin 03-18-09 08:48 AM

Quote:

Originally Posted by waterrockets (Post 8550095)
Close, but power = torque * angular speed (not rpm). In MKS units, angular speed is radians/second.

In the CSV, just set up the following cells:

Code:

m/s                    circumference    rot/s                rad/s            Watts
(kmph*1000)/(60*60)    2.096        (m/s)/(circumference)    (rot/s)*2*3.14159    torque*rad/s

...or, paste this in row 2 of the .csv (to the right of the last column), and extend it down:
Code:

=B2*((C2*1000)/(60*60)/2.096)*2*3.14159
B2 is torque, and C2 is km/h, and 2.096 is your circumference on the head unit x 1000

Very helpful! Much easier than going through and trying to recalculate a bunch of columns.

waterrockets 03-18-09 09:46 AM

Quote:

Originally Posted by ijgoodwin (Post 8551684)
Very helpful! Much easier than going through and trying to recalculate a bunch of columns.

I also am thinking more clearly since waking up, and reduced it down to one magic number:
=B2*C2*0.832694550466497

If you have a 700x23c on the rear, that will cover it for you with a circumference of 2096. If your circ is different, scale the magic number the appropriate % to account for the difference from 2096 (1% smaller circumference = 1% smaller magic number).

Apus^2 03-18-09 10:18 AM

you messed up your sig digs. ;)

Hocam 03-21-09 05:01 AM

Maybe this has been addressed before, but when do I use NP and when do I use average power? I know you should use it for 60' power but what else? Coggans book seems to imply anything over 30 seconds is fair game but I've read some comments here asking for average power instead of NP for short durations.

For instance, my 5' max with average power is 289 but 360 with NP. 360 seems really high given an FTP of 245..

What about 20 min?

procrit 03-21-09 06:18 AM

Since NP is based off of an individuals own specific FTP, AP is a much more reliable way to compare two peoples power.

Example:

If my FTP was 360, and I averaged 360 for 5 minutes, my normalized 5 minute power would be 360. I would probably be WAY faster than you during those 5 minutes, even though your normalized power was 360, because your average power was only 289.

Normalized power is a great way to compare your own efforts from day to day, but are almost pointless to use when comparing up to other people.

waterrockets 03-21-09 06:42 AM

Normalized power is best for showing you how "hard" a workout was. It is the basis for your Training Stress Score, which leads to chronic and acute training load calculations. All this helps you track how hard you're training.

For 60 minute NP, it can potentially let you know that it's time to re-test FTP (if you see a big jump), but it's not intended to be a means of estimating FTP on its own.

You have to watch it when your NP is much higher than your average:
- For my last 5' test, my AP/NP were 452W/446W (yes, NP was lower because of a hard start).
- For my last 1' test, and the following 4 minutes of coasting, my AP/NP was 177W/475W.

asgelle 03-21-09 07:09 AM

Quote:

Originally Posted by procrit (Post 8570871)
Since NP is based off of an individuals own specific FTP,...

No it's not. Normalized power is the fourth norm of power. It depends only on power and time. http://www.midweekclub.ca/articles/coggan.pdf

Dubbayoo 03-23-09 04:24 PM

Why can't I drag 'n drop charts in TrainingPeaks? It worked with the Joe Example guy but not my profile.

Actually I just can't seem to move the summary chart. I want that at the end.

jonestr 03-23-09 05:19 PM

I am sure this has been debated before, but I will bring it up any way.

NP is a method for smoothing the data. It is supposedly consistent with some physiology that is never brought up. It seems like there should be a better way to smooth the data than just taking powers and doing moving averages. If you assume that all the noise is gaussian then your average power should be the smoothed power for a large data set.

Is anyone with me in thinking NP is a bit arbitrary or am I out on a limb here?


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