@Dan_Dima-ala this subject is close to my heart as I made a big mistake in my training last winter as a direct result of precisely this flywheel inertia effect.
So based on the results of a friend who made unbelievable progress in his racing after two winters of smart turbo training, I decided to do an experiment and do only turbo training, no road riding at all, for an entire winter. My target events are a whole season of 10 and 25 mile TTs from flat through rolling to hilly.
I live in a hilly area and thought I could get the same strength gains on the turbo as doing real hill repeats for example. The mistake I made was that I did my entire Trainerroad plan in the big ring, with the exception of the low wattage valleys. All on a Kickr Snap on ERG.
Come the season I was confident and feeling really strong. I’d hit all the workouts full bore and even discovered a new max HR in a VO2 session. My ftp was up from 242 to 275 at 70kg. I thought i was going to kill every course.
I was in for a shock. My PBs came rolling in on the flat stuff, sure enough, but my climbing performance was abysmal. I lost minutes over my PBs on the hillier courses. I worked out straight away what the reason was.
Lesson learnt and next steps: this winter I’m doing plenty of big ring high cadence workouts but I’ll be supplementing these with lower gear and lower cadence work too, via appropriate Trainerroad workouts and real hill repeats. Even on the big ring workouts I’m using a bigger rear cog than last winter to reduce the helping hand of flywheel inertia even if it means my stated ftp will be lower.
Good luck with your training!