I’ve been using the Zwift ride/kickr core 2 combo for nearly one year and the first few months involved meniscus surgery rehab, so I was not pushing things too hard. Using sequential 1-24 shifting. As I’ve been gradually giving more effort I’ve noticed that my gear changes, especially in the 12-15 range, become rather extreme and seemingly too “far apart”. Even on steeper descents, I can’t spin out gear 15 or 16, when IRL I’d be maxed out on either my road or gravel bike on similar descents. I realize that with my trainer difficulty at 50% that the descents are “flattened” but this doesn’t seem right. Perhaps the best way to describe it is that when I’m in bigger gears it almost feels like I’m simultaneously braking. Any ideas on settings or changes which might address this?
Appears to be the same on the WattBike, it has 22 gears and started gear 10 and now use gear 11 on the flat. Have gone all the way down to 1st on the Alp but never get above 18 on a downhill.
I leave the trainer difficulty at the default, had a play with it and didn’t like the changes. Could be partially a weight thing. Something a little more sophisticated in Zwift is probably required in that you can change the cassette to line up better with your full range, like choosing the number of teeth for 1 to 22 in my case with the option of a click back to the current default.
Zwift halves downhill gradients even before trainer difficulty is taken into account.
I believe I put my Atom into 20 or 21 for the 100kph badge on the Radio Tower descent. 
Must have got mine on 18.
Obviously being able to fully customise the cassette is a far better way to go. Maybe make this option only available to those with decent hardware, which would also probably mean you have some actual road experience and know how the gears are supposed to work. I would have one lower still than the current “1st”, was forced to keep up the cadence or would have died. Not sure what would have happened if I had stopped. More options on the flat with gear 10, 11 or 12 and only hitting 22 doing over 100km/hr.
Not exactly screaming for the change my old 1980’s road bike is a 14 speed.
Good info, thanks. Similarly, I’m between 11-13 on the flat typically, so I thought I could easily ramp up to 18-20 on descents but that’s not the case (I have not done the Radio Tower yet).
That helps explain the unrealistic need to crank it on descents to maintain speed in some cases.