Interesting points. I initially ignored left right inbalance as i thought that if I had it, it would be consistent from day to day. But it looks like garmin have updated their software in the last couple of weeks and it now shows torque effectiveness left ( about 75 ) and right, pedal smoothness left ( about 21 ) and right. These figures do change slightly from one activity to the next and I don’t really understand them – especially as i only have a single sided power meter.
The air temp in the room drops by about 4C over 1 hour – i have the doors open to the garden and a fan blowing, hadn’t really thought about bearings getting hotter but surely that would happen for all workouts?
Would a change of tyre type have a significant effect – same pressure and width but the one used that gave the lower power readings feels like it has softer sidewalls