Cycleops Powercal - Cheap alternative or waste of money?

[tms101]

Just got a Cycleops Powercal chest strap and have been using it on a variety of bikes. Don't know if anyone out there has been able to do a good analysis against a Powertap Hub or Quark but the balance of my riding appears to give me some pretty poor numbers. I had the chance to ride next to a friend who has a Powertap hub while road riding and it appeared to be off by about 40 watts! Now, I would love it if I could simply say, yeah, just add 40 to my indications! However, it doesn't appear to work well that way. It will vacillate from 50 to 180 during a climbing stretch while holding a constant rpm and heart rate. It's kind of a cool idea, but simply using an algorithm to formulate power might not be there yet.

[false_Aest]

You should've read the copy for the product and realized that a hologram a more effective training tool.


Repeatability is more important than accuracy. HR based power seems to not take into account little things like, "How many cups of coffee, how much sleep, did you just pee, did you watch pr0n in the morning, how hot is it, how long is your hair, what tires are you using, how dense is the air, what time of day is it, did you life weights yesterday, etc etc etc etc etc


As an average of power I think it could be "accurate" but I don't think it so strong on the repeatability. .... unless you start to average your power over weeks/months/years. At that point, using a stop watch might be just as helpful.

[tms101]

Yeah, I would love to see the hair growth factor on the Garmin! I do believe youre correct with the average, however, it appears that the average may still be off at the end of the ride, rides, and 1 year down the road when I finally succumb to the wristwatchitess.

[Bruce K]

A buddy got one for cyclocross. Seemed simple and relatively easy as a tool to track power during races.

Software glitches in his lead to a discussion with Saris where they are sending him a USB stick with new software.

In theory it sounds good and once the bugs are out I am betting it will work just fine to a reasonable level of accuracy. It won't replace Powertap hubs, Quarks, etc. for accuracy but it will be good enough for certain activities.

If it ends up working as advertised I will be getting one.

BK

[false_Aest]

I don't really understand how this is a better training tool than a simple HRM.

Basically you're getting an average of HR. You might as well be converting that into hotdogs or Camel Cash.

When it comes to doing intervals the benefit is hitting LT or whatever numbers you want and seeing those numbers immediately... not after X amount of time.

30 sec on 1 min off becomes nothing when your HR tends to lag behind 45-90 seconds.

I think a better training tool would be to get a trainer and understand the powergraph that goes along with it. You do your FLT test and then start working on a program to make that grow. Your power is directly related to speed (e.g. 20mph - 276 watts) and you know what targets you have to hit to do it.

On a CX course I wonder about the transitions between running, mud, grass, pavement, etc. I suppose one could average the wattage over the race but what happens
when the course changes?



PS I like tech
and want to like this thingie
someone convince me

[bing181]

I don't really understand how this is a better training tool than a simple HRM.

Basically you're getting an average of HR.

You're not actually. Cycleops haven't said all that much about exactly what's going on under the bonnet, but it doesn't follow HR per se. You can have high HR and low power, and vice versa. On "off" days, where you might have an unusually high (or low) HR for a ride, the Power readings you get stay where they should be. It's also responsive - when you crest a rise for example, the power reading drops pretty well instantaneously, while HR (well ... my HR!) can take minutes to drop.

It's obviously not measuring actual power, so real power could be higher or lower (higher in my case). But it's consistent in those readings. i.e. if it's out by 10%, it's always out by those same 10%. I'm getting readings very similar for similar rides on my various loops.

Where it's not great is short term and instantaneous readings, as the real time readout fluctuates a lot. But, it doesn't fluctuate randomly, and on a climb (for example), it's pretty easy to work out where you're at. But if you want something to use to give you accurate readouts for intervals, this perhaps isn't it.

On the other hand, the global power figures are repeatable, and give you reliable data to use in programs like WKO and Golden Cheetah to manage your training. And that's where it's a big improvement over just having HR. Given the price compared to a standard ANT+ HR strap, it's more than useful, especially for those of us who don't want (need) the expense etc. of a full hardware power system. The other great plus is you can easily use it on different bikes, or even different activities (running or cross-country skiing for example - even though obviously, it's not measuring power per se).

[Bruce K]

Actually I don't think it's much good for other sports as it needs the speed input from a sensor to make its calculations.

BK

[Spicoli]

It is not meant to replace a power meter, more to work along with one instead of buying a seperate PM for other bikes you may own. Good for those who want to assign a "training stress" number to lower z 1-2-3 type rides/workouts at a lower cost on bikes 2-3-4..,whatever. Anything in the higher intensity range/intervals are too variable for it to track with accuracy because of the reasons stated above. HR vs Power tracks close enough for longer duration efforts. This is how it was explained to me.

IMO it looks like a bit too much work to pair/set ranges within it to me. Most cyclist who train with power can estimate the TSS of lower intensity rides done without a PM. Not that those really need to be all that accurate anyway.

[bing181]

Actually I don't think it's much good for other sports as it needs the speed input from a sensor to make its calculations.

BK

With all due respects, it doesn't. It ONLY measures HR. I can run round the block a few times and get a TSS score.

Seems to be quite a bit of misunderstanding about Powercal ...

[esldude]

As it uses HR, it could at most determine your metabolic output. There are some decent formulas that can do that. Basically you burn X amount of energy at rest. Doing anything other than resting raises your heart-rate.

I have used a formula with several adjusting coefficients, but basically your heart rate goes up about 11 bpm per met. Subtracting resting energy and assuming the difference is activity with an adjustment for muscle efficiency one can get a power output. I have messed around with that enough it is reasonably good across a wide range. It fails at very high efforts above 85% max.

One's resting HR can be effected by caffeine intake, stress, or rest etc. But if you get a pretty good number by avoiding those you can be reasonably close. At anything much above resting the effects of stimulants and such seem very small vs activity. Walking, running, walking up a sustained incline etc. the calculated amounts track with such a formula as they should. I would venture it good +/- 10%.

Now I don't know how this product gets its baseline. The idea they have algorithms from research etc. might be right, but if it doesn't use your basal heart rate as a starting point they have to be in error.

Of course, other than just curiosity of comparing watts to watts, I don't see it being better than HR for training. For that matter watts would not be all that useful except it shows you putting out more watts as you become better conditioned. The HR should go down for a given speed with better conditioning or at same HR speed should go up. Same difference if you will.

[nm87710]

:(

Good Luck!

[bing181]

Of course, other than just curiosity of comparing watts to watts, I don't see it being better than HR for training.

Having trained with only HR for years, for me it's definitely an improvement on HR training, and is more reliable and repeatable than HR. I no longer have to adjust for the variabilities of HR - in my case, for example, HR is generally higher in the afternoons.

I can't imagine anyone selling their Powertap or Quark to get one, but for a small extra cost on a standard ANT+ HR strap, it's more than useful. There are a handful of side-by-side comparisons around the net tracking Powercal against Powertap (or whatever), and it's definitely close (enough) for most of us.

Agree with the previous post as well ...

[Bruce K]

Mine arrived today.

Got it paired up in about 5 minutes

I read the paperwork first and then cleared out old sensors.

I ran up and down the stairs and it showed HR and watts.

Speed sensor is next.

I will ride it this weekend and report back

BK

[hairytorus]

If you feel like you've pushed yourself to your limit while training then you probably have. You probably don't need any technology to tell you that.