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.

The PowerTap Experience

I've been riding with a PowerTap for the last couple weeks or so - one week in tandem with my SRM Pro on the Pinarello, and this past week or so by itself on the Cannondale I'm transitioning to.

I've done a myriad of different efforts and rides with the PowerTap, and there's a few things during this experience that have really made me think a bit.

First off, damn, trying to download the PT on a windows Vista machine was a total pain! I have an older hard wired PT pro with a serial download cable. I downloaded the newest version of the PT software off of the saris site, and couldn't get it to work since Saris is no longer supporting serial connections and only supporting USB connections (I'm no expert on this stuff, so it's entirely possible that I just didn't push the right sequence of buttons and rub my belly while tapping my head just so in order to make my configuration work out). :-)

Next, I used the CD that came with the power meter (that I bought used a few years back and had re-furbished by saris after it mysteriously just stopped working a summer or two ago) - the software I tried installing was Link ver 1.04 - and that software also wouldn't work.

I tried many times with the PowerLink Lite CD, that also came with the PM, to just download the data - and eventually got that sucker to work... Several times during the past week, though, I got weird downloads - just crap data with big spikes. These (obviously jacked up) downloads went away on a second attempt at downloading, but really, it was just a painful experience...

Additionally, I've been doing some sprints lately with the PowerTap, and it just seems really odd that I'm able to generate the exact same wattage for 3 or 4 consecutive 1.26 second samples. I seriously doubt that I'm that consistent over that 5 second-ish period. I'm not sure what to believe with that data... Oh, where is the SRM config that will work on this bike??? :-) It looks like this coming Monday I'll have all the parts I need to make that happen - but I reckon I'll have some challenges I didn't anticipate when trying to make it all work... If there is one thing I have learned in the past 35 years, it's that nothing is "easy"! :-)

The last thing I've been trying to get my hands around is the whole "interval" feature of the PowerTap. I've always taken for granted how the SRM integrates this feature. I like to see how things went during the last interval I did while I'm rackin' up those bonus points coasting back down to the bottom of the hill. With the SRM it was as simple as hitting the set button at the end of the effort and seeing the time of the interval, and the average watts of the interval. If I wanted to review the first interval while coasting down during the third interval (to see if my power to RPE ratio is in check...) I just simultaneously hit the "mode" and "pro" buttons (or whatever sequence that is that I instinctively do now...) and cycle through the interval data of interest. Takes a few seconds or so...

With the PT, I haven't yet figured out how to get the same information as the SRM until I download. But then again, I haven't RTFM. Anybody else figured out how to actually make use of the PT interval functions???

Anyway, a side benefit of the whole PT experience is that I don't really look at the display while going hard anymore - I just kinda "go hard" - ya know ridin' by feel, all retro and stuff! Interesting to note that I am not limited by the flashing numbers with the PT, and I go just as fast - well, faster on some efforts recently - than I've done in the past.

'Course - I'm a couple kg's lighter than I've ever been before too - so that confounds the whole "pissed off at the powertap" effect! :-)

Seriously, though, if anyone can help me make sense of the whole powertap interval function thing, I welcome the input!

Turkey Weekend Project

I've had this Cannondale frame/fork and build kit laying around since around March or so - just haven't had the motivation or drive to finally build it up.

I know, I know... Pretty crazy, huh?!

Well, my employer was nice enough to give us a few hours off on Wednesday prior to this long turkey day weekend - so, I took advantage of this early departure...

...and went for a ride!

hah! - but when I got back to "villa de Willett", I set out to get this bike built up!

It's been a long process, ya see, I'm kinda addicted to SRM based power and all, and this bike has/is making that a difficult thing to accomplish! Cannondale loves to do things "their way" so, that made the SRM Pro crank I've been using since '02/'03 obsolete - that Campy square taper crank compatible SRM doesn't work with the proprietary Cannondale BB/Hollowgram crank arms.

So, the quest began - and I've had lots of help along the way. First, Jason Yanota of the bikeage helped me out by selling me a barely used Cdale SRM spider/chainrings that I'd eventually be needing. Then, I picked up an SI crankarm from Craig over at wiredbike.com. I thought I was set at this point back in the April-ish time period...

Well, much to my dismay, it turns out that in order to fit an SRM on a Cdale, you need a slightly wider BB spindle. I could have made some modifications to the crank that came with the frame/fork (that I bought throug the team I raced for this year - JambaJuice/TaylorMade http://www.sd-fogracing.com ). So, it was April/May and the season was in top gear - I didn't really want to dork around with the position/bike I'd been riding for the last 15,000 km's...

Plus, I'm pretty lazy! :-)

Around comes last week, and I was figgerin' I needed to build this sucker up pretty soon in order to not be shamed on the next team ride I showed up for. So, I shot an email over to Craig @ wiredbike.com (make sure that if you are in the power meter market you give him a shot at the sale - he'll give you $50 off with a special BTR code, BTW) and it looks like he'll eventually be helping me buy an SRM compatible Cannondale spindle. Nice!

Also, a couple months ago, I saw an opportunity to pick up used SI Cannondale crank arms/BB spindle while perusing the obra.org mailing list (oooohhh, my disdain at the time for the obra officials was overridden by the need for cheap, used bike parts - LOL! :-) ).

Then, a few months passed...

With all the parts in hand to get this sucker together (albeit sans SRM power capability), I busted out the hacksaw, star nut setter, and some elbow grease/patience and finally built up the cdale on Wednesday afternoon. It went together really easily - the Campy Record 10spd parts are pretty sweet. Total pie to assemble.

I'm no pro when it comes to building bikes, so I'm sure you'll give me plenty of grief if you see me out on the road, but here it is after the first ride I took it on this morning:



Here's a close-up of a saddle I took a chance on - it's a Selle-San Marco Aspide - no padding, just the carbon shell:



I was surprised at how comfortable it appeared to be after the 70 minute jaunt I took it out for today. We'll see how it works out long-term.

You'll notice that I have a PowerTap power meter on the bike whilst I'm waiting to get the SRM on-line.

The trials I've had with that thing will have to wait for another post! ;-)

The PowerTap seems to work OK, but damn, trying to download that sucker (it's an older model with a serial port connector) proved to be quite a challenge!

As for the Cannondale, it didn't seem to make me break any of my previous records I have thrown down while going up Couser Canyon Road near where I live, but dang - new bikes always feel pretty cool!!!

I am having a bit of a hard time getting where I'd like to be position-wise - I reckon I'll need a shorter stem (120mm currently on it) and a seat post with a wee-bit more setback. Hard to get italian seat tube angles these days for us "old skoolers"... ;-)

Hope you all had a great holday weekend here in the U.S., and if you are elsewhere in the world - I hope you just had a great weekend! :-)

peace,
-kraig