I’ve got a Kickr18 and I plan on switching to resistance mode for VO2max intervals up to 2.5 minutes. What I’ve found is that my Kickr does not do well when I spin up to cadence for the interval.
When I’m in the valley I’m spinning about 85 rpm, I start spinning up to 100 rpm up to 15 seconds before the interval hits. When the interval hits my power is low and the kickr compensates by increasing the resistance which makes me feel like I’m hitting a wall, my cadence ends up dropping to 80 rpm and I have to grind it back up to 95. This then makes my power skyrocket and causes the kickr to drop the resistance, rinse and repeat until the end of the interval. You can see this effect in my workouts and it makes the interval much more difficult to get through.
I’ve found that longer intervals, probably 4 minutes or more, doesn’t have this rubber band effect because the power is significantly lower. Jumping from 100 watts to 220 watts is more manageable for the trainer than 100 watts to 320 watts.