My Lunch hour ride today...

...bonus points for those that can decipher the 3-d histograms below (they are the same plot, just from different perspectives)!






ooooh - look at the pretty colors! :-)

I haven't fired up this matlab script in awhile, but when I do, I find that it's a pretty descriptive way to discover the "gold" in my srm files.

From the looks of it, it seems that I can do about 13+ minutes @ 6+W/kg in 70-80 second chunks in around 40 minutes.

Sprints with the PowerTap

I mentioned some oddities I experienced with the powertap I currently have on the bike I'm riding a few posts ago - ya'know, the whole exact same power readings during a sprint deal.

Here's a a screenshot from the download of yesterday's file where I was doing some sprints:

one thing to note is that when I stopped pedaling, I then glanced at the PT head unit as I was coasting - it kept reading the same value for a bit - and this observation is reflected in the download.

So, this observation would suggest that the PT is doing some unknown filtering in their data acquisition. This could be good, or it could be bad - in the case of short efforts , it appears that it's doing some weird things as it relates to reality.

Not that this sprinting observation really matters in the grand scheme of things (it's been kind of refreshing for the past couple weeks not to give any credence to the flashing numbers on the power display!) - but it is a worthwhile thing to note.

Speaking of power meters - did y'all see the dueling press releases from ergomo/gita this past week?

Guess that is a partial explanation as to why I never got an ergomo to evaluate from the "important folks" at ergomo-usa. Then again, the excuse I continually got was that "there just isn't any availability right now for demo's" - or words to that effect - which from the sounds of the Gita position is a factual statement...

Anyway - I reckon my original thoughts on the ergomo still have some relevance:

-measure one leg and double it and all the doubt that that brings up

-ease of installation

-reliability of "zero-ing" out the unit prior to riding

-measure one leg and double it and all the doubt that that brings up

did I mention "measure one leg and double it and all the doubt that that brings up" ;-)

Seriously, though - I reckon if a gadget helps you ride your bike more intelligently/purpose/reliably then that's a good thing.

I used to keep training logs back in the day where I'd actually write things down - that was a good tool to make sure I was doing what I had set out to do on a given day. Nothing like the satisfaction of writing down HR's and times and distances and RPE's in that journal entry for the day!

Downloading a power meter file can have a similar effect on training, in my experience.

Power File Databasing

Spent a wee-bit of time figuring out how to decode the binary bits and bytes of the SRM power meter file format.


Great insight and c++ code over at goldencheetah.org.

Here's the first little bit of code in the script I wrote for batch importing SRM files and creating a matlab database for subsequent analysis:





With this piece of code, it's pretty easy to simplify big jobs like putting together plots like the following for 300+ power meter files (this plot was kind of inspired by Dr. Allen Lim of the Saris Group in this Q&A tidbit - http://www.saris.com/t-PowerTourQA.aspx#NormalizedPower ):






For those interested in further reading about this plot that orginally appeared in an old article on the main btr site you can check out:

http://www.biketechreview.com/power/strain.htm


not much has changed globally since 2004/2005, eh?


Anyway, this database creation tool I've created is pretty cool - it sequentially opens up each individual file in the native SRM format and processes the data any which way you like - well, at least any which way you can code something up! pretty cool, huh!?

oh, man, I'm a total dork... ;-)