I've had Vector 3's for over a year now along with a Kickr Core. Last winter I changed my crank length from 172.5 to 165, and adjusted the setting on my Vectors accordingly. Since then I've noticed that my Vectors seem to be underestimating my power compared to before. Initially, with the 172.5 cranks, my Vectors would report very close to my Kickr - usually a few watts higher, which is what I'd expect. Since then, it's about 5 - 15W lower, varying somewhat over the power range. Both have been calibrated, firmware updated, etc, which doesn't seem to make an impact. I use the Kickr power for my workouts as I've found that using the Vectors for power in ERG mode seems to induce a sort of oscillation presumably due to lag in the control loop (engineer alert). I've also seen in outdoor rides that my speed/power relative to mates which are smaller/lighter than me seems to be low.

Anyways, I'm wondering if anyone else has seen this when switching cranks on the Vector 3's. Obviously when riding outdoors I'm relying on the Vectors, so the discrepancy has a real impact. My idea for a "quick fix" is to simply adjust the crank length from 165 to something that will bring the power inline with the Kickr - presumably this is close to the 172.5 from before, which seems weird. Maybe when I enter "165" into the system it's not registering somehow (though it does come up as 165 when it prompts me). Thoughts?