@tpodowd 50x19 has the Kickr reporting something like 18mph, depending on cadence.
@mcneese.chad a year ago in November I started experimenting with gearing in Zwift. Nothing in the little ring felt natural, the experience was unlike riding outside. And same gearing experiments when starting with TR last December. With big ring everything feels like riding outside, and that’s why I stuck with big ring and middle of my 11x32 cassette.
Chad, IIRC there is a sizable difference between our weights. I’ve always ridden in the 200-215lb range, so perhaps the extra momentum I carry outside is the reason the small ring feels unnatural on the trainer.
I’m 145 lbs [66 kg], so that may well make the difference.
Great point, and one that is easy to miss/forget.
Outside in a pace line filled mostly with people 130-170lbs, I’m constantly having to ride outside the line to add wind resistance and slow down (or brake). And gentle declines / false flats I’m rolling faster and need to brake to stay in my place. My ride leader is 3" taller but only 175 and drafting behind him requires constant attention to avoid crossing wheels. Definitely seems like I’m carrying a lot more momentum than other riders that are ~60-75% of my weight.
That mirrors comments I hear from some heavier riders around here too. It is a challenge because each size range has adjustments to make depending on conditions and road profile.
Momentum explanation for the win. Last night I was starting to think y’all running small ring were short changing workouts 
My frustration with the Kickr/TrainerRoad is that it often fails to apply sufficient resistance to the pedals at lower wattages. On a road bike, the pedals never cog or over rev unless you are in a ridiculously low gear. I find the way the Kickr applies pressure in Erg mode is very unrealistic. With any reasonable resistance, I should not be spinning faster than the trainer. When I ride on the road, I adjust my gears for the appropriate resistance unless I’m coasting. On the Kickr it feels like the bike coasts momentarily making a smooth cadence turn choppy and unpleasant. Am I doing something wrong?
INTERESTING!
I am also a smaller rider (145-150lbs, 5’7") and primarily a mountain biker (though I ride road in clement weather) and I have always used the lowest gear possible on the trainer that doesn’t create a wattage ceiling. I find this feels to me, extremely close to riding outdoors where the bigger gear/higher inertia feels way off. I hadn’t thought about the difference in other factors that you guys have highlighted.
I currently run in a 39/19 but a couple of years ago I was riding in the 30/19 but FTP increases and wattage ceiling meant I’ve worked to where I am now.
Earlier this year I turned off Erg on the Kickr direct-drive. Now using Standard/Level mode and much better, even more like riding outside.
I have noticed the same thing. Recently switched from a first gen Tacx NEO to the new v5 Kicker and am not too thrilled about this specifically. The NEO managed ERG much better than the Kicker does. I also did a few sprints and had to wait for the flywheel to slow down before I could pedal again. This took long enough to pause the workout? The only thing that I have found that works for me is to do the interval or sprint in the small ring and then shift to the big ring right at the end. Its very frustrating since the NEO handle this so seamlessly.
Much of this Neo vs Kickr is a differences between the real or virtual flywheels. The Kickr has real momentum/inertia at play while the Neo is “fake” in that is uses the system to propel at the same time as adding resistance (more complex than I think we might realize).
In the case of a real flywheel, and as a result of “sprinting” which drives the rear axle (along with the flywheel via the belt drive), will have lots of energy in it from that sprint. When we reach the end of the interval, the power/resistance drops in accordance with the workout intention to give a recovery. But we have the flywheel really ripping in most cases, and that leads to a long spin since the resistance in ERG dropped a ton.
It’s not a great thing, but it’s also not the end of the world. I sometimes use a longwinded trick to get it to spin down faster, and will share if there is interest, but it’s a pain unless you are on Win/Mac, and even then it’s a hassle.
As mentioned, kicking up to a harder gear to “catch” the flywheel can work and you just allow your cadence to drop and then shift back down to the “normal” gear. In any event, the worst case is that you could coast to wait and maximize your recovery in that interval.
It would be possible for TR to ramp down the resistance instead of the sharp drop, to control the flywheel sooner. But I’d wager that we’d here complaints from people saying that the recovery taper is a pain and not allowing them to relax. Likely a win/loss situation.
is to turn off Erg and do sprint workouts in Standard/Level mode on the Kickr direct-drive.
Oh, and you can turn off auto-pause in TrainerRoad app settings. IMHO that should be turned off by default.
When I’m outside doing sprints, there is a lot of momentum and on a really fast windup I stop pedaling at 140-160rpm. And my bike computer keeps recording. Your Kickr is behaving a lot like out on the road. And if you turn off auto-pause in TR app, then the app will behave like your bike computer.