I get to race a nice bike at cool places thanks to these guys:

Monday, August 19, 2013

Update to Stages Post


I messed up on the last post.  I didn't crop the power files correctly to compare my average power.

Here are some pictures to compare:



Yeah, these are EERILY similar.  As I'm posting this, I'm going back into WKO+ to make sure that they are, in fact, from different devices.  The full files are different (Stages drops power data at under 30 rpm...when I crossed the line and ultra-soft pedaled around after the finish), but I wanted to show the interwebs just how close the Stages compares to a known high-standard power meter (honestly, I think of Powertap as a secondary Gold Standard, similar to SRM) at the expense of giving away my super-secret power numbers.

After cropping both files more carefully (one of them left out some of the starting lunge), the averages are: 303 and 303.  I don't think there is anything more I need to write (except can we have an Android App to upgrade the firmware?)

Sunday, August 18, 2013

Stages Power Meter: First Thoughts

For six years (I got mine when I was 24), I've been a devoted Powertap user.  When I started using my Powertap, I had no ideas what the numbers meant, but was happy that I could boast about what I did up a hill with my friends after a group ride.

Through the seasons, I began REALLY using the thing and training with purpose.  For a while (the second half of the year I wore the 'Your Ad Here' kit), I did the 'Training and Racing with a PowerMeter' plan...entailing a lot of 2x20's at 90-95% FTP.  My big weakness, endurance and long-range power, increased a lot with a healthy dose of BORING work on the rollers, staring at Powertap numbers.

In 2011, the North Tek year, I made some STRONG progressions, with some big peak performances at Wilmington and Altoona.  Again, I knew enough about FTP and sweet spot training to self-coach my way to all of this.  in 2012, I rolled my way to the Nature Valley Grand Prix, where I focused on keeping a high average power on 4+ hour rides and starving myself to a svelt weight.  I had a massively disappointing performance at Nature Valley, and it was after some chats with Lindsay Bayer that I decided I needed to suck it up and invest in a coach.

The last half of 2012 I was coached.  The holes in my fitness were quickly sured up, and I began to rack up power data from more 'traditional' style workouts, with plenty of high-intensity efforts, and a HEALTHY portion of vomit-boiling sprint work.  Unfortunately, that November, I tore a muscle in my leg and was relegated to rehabing couch-potato style for 3 and a half months.  This May I resumed business as usual and got back to hard pedaling with my trusty Powertap.

One thing that ALWAYS bugged me was having to chose between running my Powertap on race day and collecting the data, or using a race wheel.  While I can't say I've ever won or lost a race because of this choice, the mental boost you get from having your nice hoops on is significant.  In my case, I have an 808 front, which quite frankly, looks ridiculous paired with a standard alloy rear rim.

Enter the Stages Power Meter.  A few weeks ago, Bike Doctor Waldorf became a StagesCycling dealer, and a few of us on the race team decided we wanted to get into crank-based powermeters.  For me, there were three factors in wanting to try StagesCycling: I LOVE Shimano cranks, and have been apprehensive about Quarq for this [silly and personal] preference.  Secondly, I cannot afford an SRM.  Third, Garmin Vector [was] in my mind, VAPORWARE.

Knowing full-well what the prospect of left-leg only power measurement could bring, I decided to get a Stages Dura-Ace crank.  For you numbers-weenies, I do lurk on Wattage and Slowtwitch, so I know about the poo-pooing that has been levied upon this product.

When I got the crank, I ran it in tandem with my Powertap, borrowed an extra Garmin 500, and recorded a workout.  Disappointingly, the Stages meter was significantly off from my Powertap readings.  The next day, I found a friend with an iPhone 5, and used the free Stages Cycling app to check the firmware.  Sure enough, there was an update available, that was easily applied to the Stages unit.

Again, I went out and did a workout with two Garmin 500's.  HAPPILY, the numbers I saw in WKO+ that night were VERY congruent (for the most part).  Some numbers over 3 minute intervals agreed between my Powertap and Stages crank.  I checked calibration before and after the efforts.  While the numbers are not 100% in tandem, I would say the Stages was easily 'close enough' to train by and go home and see what you have done.  I'm talking 6-8 watt difference in Avg over an intense 3 minute effort (some jerky launching and desperate pedaling going on!)  On Saturday I raced at the Church Creek 40km Time Trial, running both my Powertap and my Stages crank.  Over the 52:35 effort (*pats self on back*), there was a TWO WATT difference in the avg power recording between the two power files.  Spoiler alert: I did a 301/303 average.  I'll let you do the math as to the percentage error that is...

More significant than the difference in power recording was the difference in Elapsed time between the two Garmin 500 units.  They were 25 seconds off of each other, and neither was consistent with the official measured time (we had timing chips on our bib numbers!)

When I mentioned for the most part I should fess up that the Stages doesn't do a great job in showing similar numbers when I do sprints, but in its defense, I've read that the Powertap tends to give high peak power readings.  More to the point, there is no 'wattage zone' you need to stay in when you do sprint work.  You pedal as hard as you can.  There is no pacing, aside from the difference of a 10 second max and a 30 second sprint.  The only significant thing I've used sprint numbers for is to stroke my own ego when I start to break the 1x00 w barrier.

All that said, I think the Stages Cycling powermeter is a great product.  You can get into reliable (but not the most pure) power measurement for under a grand, you can swap your meter between bikes a little bit quicker than an SRM or Quarq (as long as you have multiple base-cranks!), AND YOU CAN RUN YOUR DURA-ACE CRANKS!  Also, not worrying about what make/model/size chainrings are on those cranks is another plus (although this is not the big issue it once was).

If you are considering a Stages powermeter, I'd say go for it.  It isn't the perfect powermeter solution, but it is a great way to getting in to training with power, or racing with a powermeter if you are economically constrained to a Powertap laced to a training rim.  Since I bought mine, Garmin Vector MAGICALLY FELL FROM THE SKY and became available to consumers.  The Vector looks like another great new addition to the power meter market, but at Quarq-like prices (and I hope you don't mind using an Exustar pedal body and cleats).

To put it simply, if I the 24-year-old me were shopping for my first powermeter TODAY, the Stages product would be a no-brainer. If you started the whole powermeter game with a Stages, a few seasons on, you'd have a tough time finding a reason to drop over $1.5k (up to over $3k) to get a little more 'sciency' with your power measurement.  You can feel confident in riding a Stages powermeter, and use the money you could have spent on an established 'premium' meter for a coach, good food, and race travel funds.

See the folks at Bike Doctor Waldorf to order yours, and get some empirical data to go with all of your Strava records!

An elegant and affordable solution to power measurement!

No one has said anything about my mismatching 6700 and 9000 arms!  My bike LOST WEIGHT when I installed this power meter!