Originally Posted by
topflightpro
I've had PT, Quarq and SRM pms.
In my experience, each gave me different numbers. 300w on a PT was much easier to hit and hold than 300w on the SRM. Quarq was in the middle. I also know it was much easier to hit very high sprint numbers on the PT than my SRM, though my highest recorded power came on the SRM. And when on the Kickr and using the Wahoo app, the Kickr numbers are usually about 5-10% higher than my SRM numbers.
At this point, I have SRMs on three bikes, and all three give me the same numbers.
I also now have a Stages that I took off my wife's bike before she sold it and doesn't fit on any of her other bikes, but I haven't used it yet, so I don't know where it fits into this.
Interesting, I find my G3 agrees with my Quarq dFour almost to the watt. I have no idea if my Direto is accurate or not, I only use it for terrain simulation (I pair my Quarq to Zwift for power).