Currently, my rim braked Bianchi is sitting inside cos it’s grim so I’m preferring the disc on my gravel bike. I am missing my power meter, a Stages 105 LH crank, so thinking about getting one for the gravel bike.
Sadly they are different lengths so can’t just swap them. Stages GRX in 170mm seems a bit hard to come by for UK shops I recognise so looking at an Inpeak LH crank which is about the same price so not the end of the work. I’m not pushing megawatts nor training like a pro but from a measurement and consistency point of view is they much wrong with running different brands across the fleet?
In my opinion using different power meters (regardless of brand) is where at least some potential small complexity can exist.
In our household we have a variety of brands and meters. Because some measure in slightly different locations we can compare them at times and I have noticed some consistent variation between a few of them (same brand and different brand).
If you end up with meters that align well, things could be very easy to deal with and life full of sunshine.
If you end up with meters that consistently read a few to five percent different you may find yourself frustrated or struggling to setup your zones or FTP between bikes.
Many meters allow a user adjustment of slope, which is often not recommended but if it aligns a slightly outlier of a meter with the rest of the fleet maybe that’s a good idea.
I would have guessed that any shimano hollowtech left hand crank will fit on a GRX groupset…so there is that to consider.
“from a measurement and consistency point of view is they much wrong with running different brands across the fleet?”
If we’re talking about left-hand OSG array power meters you can make any power meter match any other power meter regardless of brand. Just use some direct drive trainer (preferably equipped with an OTS power meter) properly warmed up to pick zero offset factors until all three match. Bing, bang, done.