Upgraded to power meter, now something seems off


(Nick Kiger) #1

I recently upgraded to a power meter after using the classic set up for about 3 weeks. I have noticed a significant change in my watts/kg reading. I can understand if it were small but I’m getting blasted every time I ride now. Am I doing something wrong or maybe I was doing something wrong before?


(Eric C. (Zwift HQ)) #2

Hi Nick,

Make sure your power meter is calibrated before each ride - the documentation that came with it should tell you how to do this.

If it’s calibrated and you’re still not generating as many watts as you were before then your previous set-up is at fault. A power meter generates wattage data directly and very accurately (if it’s properly installed and calibrated). Zwift just takes those numbers and uses them to calculate speed in game.

zPower/vPower can also be very accurate as long as your set-up remains correct. But we have to take the speed of your rear wheel and use an algorithm to determine power generated, so it won’t ever be quite as accurate as a power meter.


(Nick Kiger) #3

Thanks, Eric. That’s what I feared. I do calibrate before every ride, so something must have been off about my previous set up, although it seemed accurate. I’m wondering if my current trainer set up is still having a negative effect on my watt output. I’ll need to keep tweaking it but have not been able to find any real information out there on how to tell if my Fluid 2 has the right resistance.


(Nick Kiger) #4

I figured out that two things were off. My tire pressure was low and my resistance we set incorrectly. Fixing those two things made a huge difference.