Hi having just read dc rainmakers very in depth review im just wondering if anyone out there actually uses one of these , i understand theyll never be as accurate as a true power meter but just wondering how they fair in the real world. Any info or experience is grateful .

TiRed of this parish uses one, and says it works better than it should, basically the same as DCR says.

I use one when on a bike without a PM. IME they give a reasonably good approximation of NP and TSS for a ride. They seem to work better for some than others. You can’t really ride to power using one though.

Seemed to me that if it approximates power from heart rate (i.e. some formula or algorithm), I may as well train to heart rate. For the steady sessions I’d do outside, heart rate seemed more useful – easier to ride in a particular zone than the wildly fluctuating figure the Powercal would generate.

I bought a proper power meter shortly after buying the Powercal.

It gives you a TSS and things though, I know when I used WKO software you always had to guess at a TSS for rides with no power meter – Like everything on a mountain bike. This fills in some of the gaps. I’m tempted by one as my HRM is playing up at the moment.

But yes, you’re not gonna use it to train to power.

Definitely not for training but like the idea of tss and as you said fill in some blanks.

I like mine. It fills in blanks on my garmin and strava. It under-reads hard efforts with a definite central tendency – this from calibration in races with dual garmins and my stages crank. It’s very reliable, of course (unlike every other power meter on the market).

But to be honest, I find that heart rate zones are just as good as power, and it becomes second nature to adjust heart rate to account for wind, gradient etc. For me Power(watts) = 2 x HR – 80 bpm is a very good measure indeed. The more I study and use power, the more I like heart rate, so in that respect the PowerCal is very good. Just understand its limitations.

Real data is probably more helpful. I’ve been riding 20/40’s to work – 20 second maximum sprints with 40 second recovery. Heart rate does not change very quickly – the usual shortcoming, but powercal power changes faster so could be seen as meaningful. Since these are ridden on a fixed wheel road bike, cadence = speed = power anyway, so it’s nice to see the profiles. My Strava trace for last week here if you are interested – 15 min warm up. A pyramid loop followed by some 20/40s and then a warm down to work. You’ll spot the sprints (Lap3), basically I sprint until I get cadence above about 120. Heart rate does show the effort, and powercal changes faster. Real power is really cadence and speed (remember it is a fixed wheel road bike), once wind is adjusted for.