Staying with a group - delayed response to power increases

Hi all,

I’ve been trying a couple of races and group rides and really enjoyed them, but I am finding it difficult to gauge my effort to maintain position within the group. I tend to oscillate between slipping back and then shooting through the group and off the front. I think this is because there is a delay between the efforts I make and the response of the avatar. To be clear, there is no delay between my effort and the displayed power (and I have turned it to instantaneous) but what happens is I will push for 10 seconds or so and nothing happens, then even if I ease off at that point I will then shoot forward and go off the front of the group. Is this because power is translated into speed which is then retained for a while? I guess practice may improve this but it’s slightly weird that it takes such a long time to respond to increases in power. I suspect “sticky draft” may also be having an effect.

Just wondered if anyone had any advice to help. I’m using a Tacx Vortex smart trainer connected by Bluetooth to iPad.

Thanks all!


It is normal for there to be some delay between your real world actions and that of your Zwift avatar. However, 10s is far beyond ‘normal’. You might consider being less abrupt with your application of power, think smoother. Also apply big power slightly before you need it (e.g., off the back). Once you lose the draft, you will definitely need an even bigger boost of power to get back on. If you have truly gone off the back, you will typically need to chase around at least 1W/kg more than that of the group. Lastly, as you get used to the courses/routes, you will know when the group tends to speed up or slow down as well as to what extent.

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Are you sure that the 10 seconds delay is not an exaggeration. There’s bound to be a small delay between power applied or reduced as the 1’s and 0’s wing their way across the ether, but 10 seconds is way too much. I also use a Tacx Vortex with Bluetooth to Apple TV box, and I would say the delay is nearer 2 seconds which after a time, you learn to anticipate.

Could be! Is it easy to capture a video?

Yes you can sed OBS studio it is very easy and free. there is a lot of info on the web.

I’m using a Vortex and Ant+, so not the same situation - but I think there’s about a 4 second delay for me. Certainly it’s anything but instantaneous.

As others have said,10 seconds sounds unusual if not unlikely.

As for learning to ride in the draft; that’s exactly what it is. You have to learn how your trainer responds to your input, and ride accordingly. For me, if I’ve ridden hard to catch a group I ease off the power several metres before I catch them. I also watch the riders nearby list, and the little nameplates at the bottom of the screen. If I see a group is catching me, I accelerate to anticipate the catch.

You ask “Is this because power is translated into speed which is then retained for a while?”, and absolutely that is the case. As with real riding outside, you don’t slow down as soon as you stop pedalling. Well, you do, but not quickly. If you ride at 15mph then accelerate to 20mph and stop pedalling, it’ll be a while before you’ve coasted back down to 15mph again. It’s the same on Zwift. (Obviously if you’re riding up a hill the deceleration is much faster…)

My experience is the same as Richard’s. I haven’t timed the lag I experience, but 10 seconds sounds about right depending on group/ride size. As others have mentioned, learning to anticipate the lag helps some, but I still have to constantly adjust my effort to maintain position in large groups too. Only thing that sort of works for me is to catch a smaller group, outside of the main pack, that are riding near my planned ride effort level. The lag seems less in small groups for some reason. My setup is Windows 10, Wahoo Kickr, and ANT+, so I don’t think the lag has anything to do your equipment config. It just seems that calculating all the ∆v’s in a large group isn’t speedy, and the ∆v’s don’t seem to be applied at the same time for all riders in the group?

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10s is not normal. Anything more than 2-3sec is not normal. Even if doing TdZ stage with 5000 other riders, you should not be seeing 10s delay in your actions. If it is really 10s, then I would expect that you have some network connectivity issues, as in delay in your upstream network connection and/or packet drop.

There is also another factor to consider.
Imagine a group of 5 riders putting down the appropriate power to stay together. The riders may not be producing the same watts or the same W/KG because their wts may vary.
anyway, they are all riding together.
the person at the back will have a slightly faster speed because of the draft and will move to the front. There, he feels the wind resistance and will slow down and drop to the back of the group where he will again speed up.

If everyone in the group stays smooth and consistent, there will be a natural cycling and everyone will take a pull.
No power variations are needed.

I’m pretty new to Zwift but have been riding competitively for years and years. I’ve noticed the same lag. Maybe 5-8 seconds. I just wondered if you ever sorted this out? Thanks!

If it worked that way of course it would not be realistic. It should be the case that you need to up your effort the further up the pace line or chain you get and specifically when you step in the headwind , and depending on the size of the group considerably lower it to sit in . (Except when you are coming off the front and joining in the back of a pace line in particular.) I think the later is not too bad but the former is just not on the money as it currently operates. You can drift up to the front on the basis of having the draft that is just not tenable the moment you saw any headwind whatsoever it would hold you in station . I think the logic around this if anything is too delayed .

Hi Scott, welcome to the virtual world :slight_smile:

If you are using a Ant+ connection, definitely try an extension cable to bring the Ant+ receiver closer to the trainer. The placement of the Ant+ receiver can make a huge difference!

Thanks! I have a PC laptop within arm’s reach in front of my bike attached (bluetooth) to a cyclops hammer fan. So maybe 6’? Would distance still matter?

I found that especially Ant+ connections are sensitive to distance between the receiver and the trainer. Objects between those two can obstruct the signal as well (just had this issue last weekend after I incidentially removed the Ant+ extension cable…

As far as my personal experience goes, Bluetooth connections are more stable over distance. We had, however, for example issues with a WiFi range extender disturbing the signal in our pain cave a few years back.

From what you wrote I assume that you have the trainer connected directly to your laptop and that it is not routed via the Companion app, right? Otherwise, this can potentially cause a delay as well.

Have you tried running Zwift on a different setup (like another computer, an AppleTV, iPad or iOS/Android phone)? It would be interesting to see if the problem persists.

I do use the companion app on my android during rides, but I don’t think the trainer is connecting to it, and then relaying from android to laptop/network. But I could be very intentional about connecting the laptop to the trainer before launching the companion app. I think that’s what you’re saying.
Since the screen is so small on the android (old eyes!) I haven’t experimented much with the lag issue only using it without the laptop. But it is something I could try too.
Thanks and will let you know!

Richard, did you ever solve this issue?

I’ve been having the same problem. Zwift reads my power quickly and accurately but I would describe the speed change as an 8 - 10 second lag. For me it doesn’t matter whether I’m in a group ride/race or not. Even if I’m riding solo on a flat surface, I can go from say 150 watts to 280 and hold it there and it takes 8 - 10 seconds for my speed to start to increase. And same with slowing - I can immediately go from 280 watts to 0, trainer stopped spinning - and it takes those 8 - 10 seconds to see the speed start to slowly drop.

It wasn’t an issue for me last winter (first on Zwift) because I was only doing workouts and free riding but this year I’m doing some racing and finding it impossible to stick with any group at all. My lack of experience and fitness level are reasonable culprits but I’m pretty sure something else is going on as well. Lin’s post that mentions being smoother with application of power and I’ve been practicing that and where others mention a 2 - 4 second lag, I could see that working, but with this longer lag it’s really not possible.

I also saw Lin’s post about connectivity issues and connected my internet via ethernet and can safely say that my download/upload speeds are good. I’m not sure how to solve packet drop issues.

I’m on Elite Nero interactive rollers for a trainer, and technically Zwift doesn’t that as a compatible trainer, although Elite lists Zwift as a compatible app. Is there a chance it’s related to the communication between the trainer and Zwift? I’m connected over Bluetooth to a Macbook Pro. Haven’t tried Zwift on another setup, but will try that.

I have power pedals but don’t use them on Zwift because they’re gravel/mtn and the shoes and pedals are damn heavy. But I’ve tried them on Zwift and have the same issues.

If anyone has any helpful advice or if you’ve solved a similar problem, I’d sure love to hear it. Thanks!