Smart trainer responsiveness and Zwift

They vary, my old flux was dire. The lag was measured in seconds when using the onboard powermeter (5 ish) and a bit less when using a bike mounted PM (crank thing, not sure of the brand, P2M i think?)

The Neo OG i have now is about 2-3 seconds with the onboard PM and very similar with my own Stages PM.
The kicker is what you're doing immediately before, so a nice steady state and a jump in pace/power it'll do in a second or so, enough to be annoying. But you can live with it. If you've already jumped a couple of times immediately before, it's slower and leads to over or undershooting.

What trainer and PM do you have? Because on the Neo, turning all the "toys" off improves it (so i switch them off if i'm doing serious training)

It's an Elite Direto X so pretty low end; connected via Bluetooth to a Windows PC. If I stamp on the pedals it responds in a couple of seconds, which by the sound of it is in the ballpark.

I now have a PM on my road bike, I could try that and see if it makes a difference. It's also not that responsive either tbh, I think it is aggregating data before sending it to my head unit.

Worth experimenting, but bluetooth should give you the fastest connection.

IIRC the aggregation is usually done by the head unit, or zwift.

Zwift has the display instant power or 3 second average setting, but it's on instant. But I'd expect that to only affect the display not the actual power transmission.

Direto X should be fine. My old gen 1 direto was fast enough at responding. Staying in a proper line is very difficult. We tend to use the line bunch (or hybrid as ZI calls it) as it is easier.

But I’d expect that to only affect the display not the actual power transmission.

I think it is aggregating data before sending it to my head unit.

I was meaning that this is unlikely.

My old Direto was slow to respond to incline gradient chances, also to "supertuck" iirc. Quite slow to react to ERG workout interval changes and any changes in my effort.

My Saris H3 is much better.

There is a lag.

The position of your avatar on the screen isn't an accurate reflection of your place in any pack so don't rely too much on the visual clues.

Zwift are currently playing around trying to improve Pack Dynamics, including changing drafting, auto-braking and whether you should be able to "surge" through the pack.

My Direto is bad for this.

I struggle to draft and end up yo-yoing all over the place.

I also can't do the supertuck, as the power takes ages to fall to zero when I stop pedalling. It falls quickly but then has a kind of decay, where it's still recording a slowly reducing non-zero value even when I haven't pedalled for several seconds. Probably takes 10 seconds to report zero watts.

I struggle on the rolling sections of courses during the races, like through the esses & in the jungle bits - the power lag means I have to push before the next hump but as we are on a downslope there is no resistance to push against & generate the power. By the time I can generate the power & it is registered by Zwift, a small gap has normally opened up.

I do wonder if this is a set-up/settings issue, either with the way my trainer is connecting to Zwift and/or the settings accessed through the Elite app.....I just never get round to fiddling about with it to resolve.

I struggle to draft and end up yo-yoing all over the place.

As I said, sometimes you think you're behind someone and you might not be. I've experienced this while virtual riding with a mate and we were chatting via discord. We both saw ourselves ahead of each other.

I do wonder if this is a set-up/settings issue, either with the way my trainer is connecting to Zwift and/or the settings accessed through the Elite app….

Lots of folk mention it - regardless of trainer make and model.

As I said, sometimes you think you’re behind someone and you might not be

Yeah, in the TTT that stw teams do, Phil is "always" telling me off for lagging off the back when I think I'm mid-bunch. I'm not sure what matters - if it's "my" zwift running on my PC that's deciding if I'm still in the draft, then it doesn't really matter what other users see, but I've no idea how zwift does what i does

My old drivo isn't massively snappy either.  I'm using ANT but I do have the dongle close to the unit.  I don't understand the system well enough to even guess if it's my borderline PC, my OK broadband or my borderline legs that really matters

Yeah I figured out that your on screen position isn't necessarily relevant. I think it averages out the power of your group then the stronger riders move to the front and the weaker to the back, within a certain spread. The problem we have in our group is that I'mm 50% heavier than some of the others, so if ever we find a steady state it gets blown apart as soon as the gradient shifts.

I find it nearly impossible to keep my place in a team time trial on Zwift. I’m pretty sure I know how the drafting mechanics work, and I am pretty aware of these things generally but I just can’t do it well at all. I either stay in a bunch rather than a line, or I drop off the back and shoot through when I try to catch up. If I don’t pedal as hard, I don’t catch up at all.

So my question is this: Are some smart trainers slower to report power changes back to Zwift? Is there some kind of setting I can adjust?

Same issue, Tax Flow. In normal races I find myself either flying out the front or falling off the back. Thing is the race position does tend to agree with the avatar position. Not done a tt for ages.

50% heavier than some of the others, so if ever we find a steady state it gets blown apart as soon as the gradient shifts.

Close to 100kg. Maybe the fact that we're bigger, requiring more watts to do the same speed makes the tow less effective. Who knows.