Advertise on Bikeforums.net



User Tag List

Results 1 to 5 of 5
  1. #1
    Senior Member
    Join Date
    Jun 2009
    Location
    Pennsylvania
    Posts
    104
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    Anyone using cycleops powercal (HR based powermeter)? Thoughts? Impressions?

    Anyone using cycleops powercal (HR based powermeter)? Thoughts? Impressions?

    For those who don't know about this, it's a heart rate monitor that also sends a "power data" signal to your ANT+ computer monitor. While not true power data (as one would get from a crank, pedal, or hub based powermeter), it's supposedly based on a sophisticated algorithm based on the analysis of reams of power/HR data from multiple cyclists in the databanks of Cycleops (one of the big 3 companies in the powermeter business).

    When I first heard of this, I thought it'd be perfect for my needs. I have over 15 bikes (yes, I'm addicted but that's a different thread) and 3 powertap wheels. I have 3 different computers for the powertap wheels (one's a wired comp model and the other 2 are ant+ computers - a garmin 500 and a joule 2.0). I have several other standard bike computers for some of the other bikes which just measure milage / speed etc. Uploading the power data into my computer based software program (WKO+ 3.0) has never been difficult. The problem is, the majority of my miles are commuting and I rarely use a powertap wheel when commuting as those are generally recovery pace kinds of rides and I don't like leaving a powertap wheel locked up outside all day while I work. I'm too lazy to try to manually enter the commuting milage into the WKO+ software so I never really know my total milage or, more importantly, my true weekly / monthly TSS (training stress score) for training purposes. With the powercal, I can use it on any of my bikes and whenever I'm not using a powertap wheel and easily upload the data into the WKO+ software along with real power data. Yeah!

    When cycleops first announced the powercal ~June 2011, they were designing it to be calibrated to each individual end user using his or her real world power/hr data (some kind of ramp test procedure using the powercal and a true powermeter). This, they claimed, would give accuracy in the ballpark of 5% if I remember correctly. They scratched that idea (marketing decision, I'm sure) and ultimately released a powercal that doesn't require calibration and is claimed to be within 10% accurate (again with their algorithm based on reams of power/hr data analysis). Though less accurate and individualized, it's simpler to use and they cut the MSRP in half to $100. Considering I'm cheap as well as lazy, I didn't mind the decision.

    What I'd like to hear from the group are your thoughts and impressions on how are they using theirs with training (opinions from those without one are welcomed, too). I've used mine for 2 rides now. It definately works as advertised and was a breeze to set up. I'm not one who can watch his bike computer while riding (other than some occasional brief glimpses). So, I can't comment much on what's going on during the ride. However, when reviewing post ride data in WKO+, the average power rating for the entire ride seems rougly consistent with the normalized power score i'd get with an actual powermeter for a similar ride / similar perceived intensity level. The powercal seems, for me anyway so far, to be a little higher but certainly in the ballpark of 10%. Some of the things I wonder about are how might my age factor in (I'm 2 months shy of 50yo)? Is the algorithm based on data from younger cyclists who's hr and power respond differently (max HR declines with age, right)?

    Anyway, I love my new toy, and now have little excuse not to take my cycling to the next level. All I have to do is actually learn how to fully take advantage of my WKO+ software's capabilities now! I'm new to training. In a nutshell, I started commuting 6 years ago, got my first powermeter 2 years ago to see how I might "stack up" against the "competition", and went on my first group ride last year. I hold my own pretty well in the group rides - especially in my age bracket. I've yet to race, but that's one of my goals. Up to now, my power data hasn't really been used much in a training way. It's been fun/interesting to get some snapshots of my power / power to weight / max power etc, but I haven't done any real periodization cycles to take things to a new level. I want to become familiar with that kind of training and perhaps one day get a coach. Any feedback on this would be appreciated.

    I appreciate anyone who's taken the time to read my new thread. Much of what I'm asking is personal. However, I figure a tread like this could help more than just me. Hopefully, I put it in the right place and haven't broken any forum rules.
    Last edited by ephin; 07-06-12 at 11:53 AM.

  2. #2
    Thread Killer
    Join Date
    Aug 2008
    Location
    Ann Arbor, MI
    Posts
    4,007
    Mentioned
    11 Post(s)
    Tagged
    0 Thread(s)
    I'm reviving this old thread because it seems to be the only Powercal thread on the forum, and I recently picked one up myself.

    Unlike the OP, mine seems pretty useless from the standpoint of comparison to a an actual powermeter's output numbers. I did a 60min ride on a Cycleops PT300 stationary trainer the other day, wearing both a standard HR to communicate with the stationary bike's Joule, and the Powercal to communicate with a Garmin Edge 500.

    First off, Powercal's numbers are all over the place for instant readout, and even for 3sec average, making it impossible to train in power output zones. When comparing the results after the ride, the two PMs were vastly different at various points, but within 9 watts at the 30min mark, yet more than 20w off at the end of the hour. The PT300 gave an average power over the hour of 230w, so while that's within that 10% range that Cycleops cites for Powercal, it's really a world apart in terms of power output, and really the two numbers can't be compared.

    I suppose that using the Powercal just to get a sense of ride intensity overall at the end of a ride might work if one always compares Powercal to Powercal data, but I just don't see any way to integrate Powercal into a real power based training regimen that also uses real PMs (in my case, the aforementioned PT300 stationary, and a Powertap wheel set for the road).

    I've only ridden with the Powercal a few times now, so I'll keep playing with it, and try to see if there's a point, e.g. 5min power average, where the number is pretty close to actual measured power, and I could use it to gauge pace at least.
    Chaad--'95 DeKerf Team SL, '02 Lemond Buenos Aires, '05 Novara Buzz, '73 Schwinn Collegiate, '06 Mountain Cycle Rumble, '09 Dahon Mariner D7, '12 Mercier Nano, '12 Breezer Venturi

  3. #3
    Thread Killer
    Join Date
    Aug 2008
    Location
    Ann Arbor, MI
    Posts
    4,007
    Mentioned
    11 Post(s)
    Tagged
    0 Thread(s)
    I should hasten to add that while I sound disappointed, the Powercal's performance is precisely what Cycleops states it to be, so I picked it up fully aware of its limitations. I think my 'disconnect' arises in trying to figure out what to do with the data since I'm using direct force measured data as well, and I'd appreciate any guidance or thoughts from folks on that matter.

    Since I do a lot of rides without the Powertap wheel, I think that looking at the Powercal data from those rides will at least reveal trends over time and over specific ride routes, so I'm hopeful to see those comparisons evolve.
    Chaad--'95 DeKerf Team SL, '02 Lemond Buenos Aires, '05 Novara Buzz, '73 Schwinn Collegiate, '06 Mountain Cycle Rumble, '09 Dahon Mariner D7, '12 Mercier Nano, '12 Breezer Venturi

  4. #4
    Senior Member
    Join Date
    Jun 2009
    Location
    Pennsylvania
    Posts
    104
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Thought I'd update this tread as it has been revived. I've been using my powercal for 10 months now. As I said in my original post, I use it any time I'm not riding a bike with an actual powermeter. All my rides get uploaded into WKO+ which I use for training purposes (particularly ATS, CTS, and TSB - acute training stress, chronic training stress, and training stress balance which I use for periodization / best effort / race prep). The powercal has made my life much easier as I can use it on any bike and, as I said in the original tread post, most of my miles are on bikes without an actual powermeter. I've even used the powercal on a couple rides with a bike with an actual powermeter for comparison.

    As Chaadster above note, the powercal numbers for whole ride avg power, normalized power, TSS do average a little higher than the powermeter (but within 10%). On short surges / sprints, the powercal numbers are way under a true powermeter (understandable because your heart rate does not respond that quickly to a sprint/surge). That said, however, the powercal, remarkably, comes pretty darn close to the powermeter. Not just the avg power / NP / TSS for the entire ride, but if I compare the the charts for scatter points or 4 quadrant analyses, the trends are remarkably similar. While slower to respond, the powercal does definately respond when I start hammering. It'll also go to zero when I coast (again, not as quickly as a true powermeter, but somehow, it "knows" - what I mean is my heart rate doesn't go to zero! but it can still tell). I noticed something else. My average heart rate tends to be higher on morning commutes than evening commutes (maybe it has something to do with hormone levels, circadian rhythmn, that cup of joe I have...whatever). My powercal numbers on the evening leg are closer to the true powermeter numbers compared to the morning leg of the commute. Seems to make sense as my HR seems to be artifically higher in the morning than the evening (but then again, people have different resting heart rates / heart rate responses to exertion so this could be just anecdotal). One other note, I find myself sometimes not bothering to sprint/surge as hard when using the powercal because I'm not "rewarded" with more accurate max power numbers. That's just me.

    Anyway, I am quite pleased with the powercal. At $100 MSRP, it's only $40 more than your typical ant+ heart rate monitor strap. It's limitations are quite reasonable considering what it's attempting to do. It does everything the manufacturer claims it does.

  5. #5
    Gios
    Join Date
    Nov 2004
    Location
    France
    My Bikes
    Pinnacle Rokh, Look 586, Merckx Corsa 01
    Posts
    144
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I'll throw in my 2c worth. I don't use a Powertap or equivalent, but have what I believe to be a fairly accurate Tacx trainer with power.

    My experience, basically, echoes that of ephins - with the caveat being that for me, the Powercal reads consistently high, by around 10% at 200 watts. However, I would stress that word "consistent". The values it gives are out - but are always out by (more or less) the same amount. So, it gives me a unit that functions like a watt, and can be treated like a watt, but is in actual fact a scaled version of a watt.

    As above also, there are certain HR conditions that will throw the Powercal and force the values up or down. Overall though, I find it remarkably accurate (within itself) and consistent.

    Against that, I've reached the stage where during rides I don't even display the watts I'm supposedly putting out. As was pointed out, there's too much variability, even when using 3sec average power (on my Garmin). But as a post-ride and training load/management analysis tool, I've found it very useful.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •