Awesome, thanks for the helpful info, appreciated!

Why does a power discrepancy matter? Can't you just work to the Assioma power readings?
I have a Tacx Neo 2T. It's pretty accurate but I'd rather use the same measuring device for all sessions so I use my Power2Max data indoors and out.

Your turbo will experience drive chain losses so will read slightly lower ( I find anywhere around 2-4%). This is one of the reasons it's good practice to use turbo power for zwift races and to dual record from a power meter, rather than the other way around. However, when your free riding this doesn't matter as you not gaining any advantage from it.

While you're correct that there is a difference in power depending on where you measure it, I'm not aware of any guidance that power at the rear hub is the quantity we are trying to divine. Is this stated anywhere by Zwift?
It's good practice if it's agreed by participants, or dictated by organisers. Maybe it is, but I've never noticed it. I'm aware for some official elite racing it has been required that a specific trainer is used and is the power source. While that's perfectly reasonable under those circumstances, it does not imply a best practice for others. One could argue either way about which power source would be more valid as a best practice. There is not an absolute right or wrong answer on that one unless we have an agreement on what we're actually trying to accomplish. Do we want to know how much usable power the rider is producing, irrespective of downstream losses. Or are we letting the bike on the trainer take the place of a bike on the road and saying power train losses are part of the deal. If the latter, should we be using wheel-on trainers to include rolling resistance? What about smart bikes that don't use chain drives? If it's power at the rear hub we'll all be needing either Powertap hubs or direct-drive trainers and had better make sure to wax our indoor drive trains. Actually maybe I should also set my trainer difficulty to zero and remove the rear derailleur, that's another couple of watts preserved!

No. For competitive prize racing it makes sense to dictate specific equipment and methodology, for the rest of us that's unrealistic and pointless IMO. If Zwift wanted to apply an estimated correction to attempt to level the playing field between pre and post drive train power sources for a selection of scenarios, I'd have no issue with it, but I also think it's unnecessary. If there is actually an official code of practice in existence, I'd be curious to read it, so a link would be appreciated!

Virtual racing will only ever be like against like with precisely defined equipment and practices. We're not close enough on the accuracy or consistency of equipment side yet that even simple stuff like defining where we measure power is really relevant or feasible.

I actually do pair to my Assioma power readings most of the time, except for erg-controlled workouts which are only like once a week max for me. So yes, def not a dealbreaker for me by any stretch.

In reality, I'm just looking for excuses to upgrade my circa 2014 Kickr Gen 1! Other minor complaints I have which are well within the realm of 'minor wants', and definitely NOT needs of Kickr gen 1 are:

- Noise of the fan belt, which lets out a high pitched whine. Still a lot quieter than a treadmill, and honestly doesn't even bother me after 5 minutes
- If I run Zwift off Assioma power, even with 3-sec power smoothing, the power displayed on Zwift is a lot more jumpy. Similarly, if I run erg mode off the Assioma (controlled by Kickr to lock on power) it's not as smooth-feeling with larger changes in required pedalstroke power to hold target power. Again, not a dealbreaker as it's minor

I used to not have any disposable income but I suddenly have a fair amount of it, and a smart trainer upgrade in the near future seems to make the most sense in terms of pieces I would meaningfully spend money on next, even if what I have works already.

I’m no expert, but I know that at the level I race at (A cat in ZRL (did a couple of races in EMEA E div 1 meant to be the hardest league and sure felt like it! and TTT premier league often) it is viewed as good practice and the right thing to do (obviously subjective). Feel free to use a power meter unless it’s required, it’s simply viewed as better practice the higher level you race by organisers and riders. (At least in the circles I’m in)

I very rarely use ERG mode. I don't like it and see no real advantage in it over controlling my own power output. However on the handful of occasions I have used ERG mode, it's been using power data from my PM. I'll not surprised it's smoother with the trainer in both roles but hadn't thought of it. Perfectly good excuse to get a good trainer! ;)

Poor RevBox, the allure of cycling uphill into a noisy head wind is obviously not your thing.

Your extensive experience and options are definitely of value though. Not many folk are testing as many devices as you and DCRainmaker are. Whether optimising the Zwift experience through software, faking a road experience through swaying or rolling, or freeing the bike by allowing the rear to float on rollers, each is refining in particular directions.
As you've said, it depends on what you want to achieve. None of these are needed to improve FTP (or 4dp) but they help motivate and that's not a bad thing. My reading of the original post is that a good mid range trainer isn't that much better than what the Computrainer provided twenty years ago in terms of ride experience, so where does one go to get that elusive road feel (and immersive training experience)?

The road ;)

Bazinga!

yeah I'll remember that when there's a foot of snow in the winter. i Just sold the Wahoo trainer, the Lemond is just so much more enjoyable to ride.

You aren't missing anything. We did *way* more work than people might think to get the inertial load on the Revolution "right" based on Greg's own take on what "road like" meant. It's not hyperbole; engineering did the math, then he rode it, then it got tweaked until he liked it. Ditto the resistance curve.
At the time that the company shut down, we were working on something very much like the current crop of wheel-off electronic trainers, with one difference: they had to "feel" at least as good as the Revolution. We were getting really, really close when the (ahem) wheels came off.
I'm still pretty bummed that project never got finished.


Edit to add: It's significantly non-trivial to go after "road-like" feel on an electronic trainer. There's a guy who is (was?) squatting on a bunch of IP to lock down electronic simulation of inertia, and just putting a big flywheel on the thing introduces other issues, especially when you want to do erg functionality and *also* simulate low-inertia riding, like climbing. Part of why the Revolution feels so good is it really only tries to simulate one thing, which is riding on a flat, paved road.

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Tech writer/support on this here site. FIST school instructor and certified bike fitter. Formerly at Diamondback Bikes, LeMond Fitness, FSA, TiCycles, etc.
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Thanks for the insights! Shame about the electronic trainer project that was canned. I guess wishful thinking that aspect of it could be brought back to life?

On this subject of "ride feel", TrueKinetix claims to have developed technology that gives "perfect road feel". However, their TrueBike is hella expensive and I haven't yet seen any independent review from a trusted source. Indeed, I'm not even sure if it's really available or just vapor ware?

For what it’s worth I am a big fan of zwift, and yet I think controllable resistance is overrated. I’ve accidentally used my smart trainer in “dumb mode” with zwift a few times (transmits power but doesn’t change resistance), and still found zwift to be very engaging. I’ve also used rollers + power meter on zwift while smart trainer was in the shop, and still very enjoyable. I am someone who actually appreciates my smart trainer more for the “road feel” aspect then the controllable resistance aspect (elite direto; to me it feels great, but I’ve never tried a lemond). If the lemond feels as good as you say, I would say you’re not missing much at all combining that with a power meter. Only place you’d miss out is simulating big climbs like Alpe du zwift.

I bought a second hand KK fluid trainer 6 years ago. It recently blew up. I bought a Kickr. Sure, erg mode is convenient, and it's fun getting simulated climbs when racing in zwift, but I very much miss my KK fluid trainer It just felt good. The Kicky feels like crap when not in erg mode. It's laggy, its hard to get dialed in to a zone, and doesn't feel natural at all.

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@floathammerholdon | @partners_in_tri

I use both (Core and KK) and my 'old man yells at clouds' position is that the good fluid trainers (KK, Lemond Rev, Fluid2) feel better than the few electronic trainers I've found. It also seems, subjectively, that many people turn their trainer difficulty down anyway, at least a little bit. Given that Zwift doesn't convey a sense of 'easing' when you're in the peloton anyway, I'm a bit meh on virtual simulation. I do like erg quite a bit, but I'm definitely not convinced everyone needs a full on interactive trainer to enjoy Zwift, or that they're outright better, especially if you don't care about erg. A used fluid trainer + a pair of power pedals is a nice setup.

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JustinDoesTriathlon

Owner, FuelRodz Endurance.

I also started with a KK fluid trainer (Road Machine) and just over a year ago I switched to a Tacx Neo 2T. I thought the KK felt good. I think the Tacx is similarly pleasant to pedal when cruising, although they do feel a little different in a difficult to define way. I enjoyed Zwift with the KK and virtual power (works better with this than probably any other dumb trainer) for nearly 2 years, and then I thoroughly enjoyed Zwift with the KK and Power2Max power meter. The Tacx is more a little more immersive and more interesting with the addition of gradient simulation, but to me it's not a complete game changer as many suggest. I really do like the ability to do big efforts at lower cadences than I could manage with the KK and my biggest gear, and I do enjoy the ability to feel changes in gradient which besides feeling more immersive, is great for pacing and strategy in group rides and races. But if you're using a "dumb" trainer and power meter, I really don't think you're missing out as much as many people around here sometimes suggest.

I just got a Kickr Core after Xmas to replace my Kickr Snap which was my 3rd trainer after a cheap Nashbar fluid and some toss out mag trainer from way back in the day. So far I love it. I've always disconnected "road feel" from the trainer, I just don't expect it and I'm not really looking for it. The core feels a lot smoother than the wheel on Snap that's for sure. No matter what I did before with the wheel, on super hard efforts or climbs I'd experience tire slippage, so just not having that anymore is worth it to me.