Best way for determining power differences between meters?


#1

I am currently running a 3rd gen Stages L/R (Ultegra R8000) power meter on my road bike paired to my 2017 Wahoo Kickr. I do all TR workouts in Erg Mode using Power Match.

Just purchased a new gravel bike with a SRAM 1x drivetrain and I’m going to pair a Quarq Dzero power meter to this bike.

My question is: what is the easiest/most accurate/efficient way of establishing a baseline of power variation between the Stages & Quarq? Assuming there will be a consistent % difference between the two, I want to understand this value so I can manually account for off-road workouts vs my indoor road training. Is there an alternative to simply doing a ramp test on each platform within the same time period and comparing how each trend vs. the Kickr for consistency?

Thanks for any advice!


#2

I think you could use your kicker as a reference.

Turn off power match and use the kicker as the power source. Just make sure that you have a watch or head unit paired to the Stages or Quarq to record that data.

Repeat the same workout the next day on the other bike.

You can then use something like Performance Analytics or DC Rainmakers Analysis Tool to compare the data between the Kicker, Stages and Quarq.

I don’t use power match and do something similar to this periodically to make sure that my trainer power (STAC Halcyon) and my Quarq are giving me consistent enough results so that my outdoor power is on par with my indoor power.


#3

#4

This.


#5

I do the same thing all the time, between mine and my wife’s road bikes, cx bikes and kickrs. last year i found one of our quarqs reading very high and just recently the stages on my crux was reading very low. i sent it back, they agreed it was bad and repaired it for me.

I’m ok as long as they are within 5-10w at 250-300w


#6

Yup. I’ve got a similar setup. Kickr trainer, 4iiii left side PM on my road bike and Quarq Dzero PM on my gravel bike. I paired the Kickr to TR and my iphone and then the bike PM to my Wahoo Bolt unit and do the ride. Turned out my Quarq and Kickr are within 2/3 watts of each other, but my 4iiii runs about 10/15 watts lower than my Kickr.

I usually have my road bike on the trainer and do powermatch. So when I ride outside on my road bike, everything is the same. When on my gravel bike, I just have to remember that my watts are show higher.

The hardest thing for me was to have to “lower” my FTP when I first did powermatch with the 4iiii :slight_smile:


#7

Thanks, all! Super helpful. Sounds like just measuring a workout every month or two to continually compare results is all I need. Glad I’m not the only one approaching it this way!


#8

This! I ran this test with my Kickr Snap when I first installed my Quarq and was pleased with its ability to graph the different power streams to confirm my Quarq and trainer weren’t respectively from Venus and Mars.