Summary: In ERG mode and for a given watt resistance, higher gearing (faster flywheel) runs cooler.
It’s been well established that gearing in ERG mode affects virtual road feel. But how does the Kickr generate resistance (Friction? Magnet? Magic?) and does a slower or faster flywheel increase or decrease wear? I can imagine that it need not create as much resistance and therefore reduce wear if it’s going faster… but maybe not depending on how it creates resistance. ¯_(ツ)_/¯
I generally use the smaller chainring and a cog that keeps the chain straight, and the flywheel gets pretty hot after sweet spot or tougher workouts gauged to 250+ FTP. I’ve measured the outside of the flywheel as hot as 150°f (65°c).
I haven’t yet experimented due to the myriad variables I’m too lazy to control or track (workout length, intensity, room temp, gear selection), but will if nobody has already looked into this. What say you internet geniuses?