PD4.1 causes odd RoboPacer behavior [KNOWN ISSUE - FIX PENDING]

Out of curiosity, how big are the packs when this happens? I’ve been in a few situations where it is more difficult to stay in a pack of 70-80 with a 2.8 w/kg pacer than a 3.3 w/kg one but with a pack size of 15-20.

You’ll have to be a little more specific than linking a 2 hour long video.

And yes; as I’ve said several times, these issues arise when packs get larger than a handful of people, and generally to the point of full road-width of avatars, where pacers are altered by… you guessed it; too many people.

Which is why I return to the statement of the RP’s aren’t going to be a solution to everyone’s problem at any given moment, because of how much they can be altered by the number of surrounding riders.

This overarching issue has always been a problem however, and is not specific to PD4.1, let alone PD4.

Some may find it worse with PD4.1 due to the ‘wasted watts’ situation, however what exactly is the need to punch through a blob anyway? If you’re there on a RP to ride with a big group, you’re already there doing it.

Maybe I’m not fully understanding a portion of the complaints of why you have to be somewhere specific in a blob at any given moment.

If people want an actual solution to the problem at hand; they need to go ride with a smaller group; not the largest. At which point they’ll realize that it’s the big packs that are causing these issues of not being able to pass, or altering the pace.

Think about it realistically; if you want to go on a group ride outdoors; will they always be at a pace that suits you, too slow, too fast? Will it vary each time you go and ride with the same people at the same time of day?
The answer is of course yes; everything will vary.

Throwing a million variables at something and expecting 1 constant result is where this issue is falling apart; and why I don’t understand how or why this is an actual issue; other than again, stating that RP’s are not the end-all, be-all.

Robo pacers exist to break up the monotony.
They don’t exist to cater to everyone’s needs.

I read that as: “it’s working well in the situations where I use it (eg racing), so you just need to learn it in your situations because I don’t want any further tampering which might affect my experience!” :wink::wink::wink:

Actually, I can narrow it down for me because RP riding in small (<20) groups is definitely an improvement and appears to be working well. But large (50+) groups are very different. It’s not about the overall power requirement because I’m happy to shift up and down the RP power categories. It’s the extra volatility, instability in the pack, surprising behaviour, and RP surging.

I’ll give you what I experience the most, even with a small group of say 5 or less. I can draft the bot pretty easily and stay on a wheel. Then, just for no reason at all, I’m pushed to the outside and get pushed all the way to the back, not always, but more then I use to. Then I’m forced to push 2-3 w/kg more to play catch up instead of being drafted pack into the group once I’m right behind it like it would happen in real life or even PD4.0. It gets even worse when it’s a larger group. All my rides since PD4.1, I have been having to average 30-40 watts more per ride…


That’s the feel I get also, not just from him, but mostly all the racers who have commented, hence the comment I made above. It puts a feeling of suck it up, it’s the way it is , and if you don’t like it we’ll…kind of vibe


I took his comment to suggest that while this thread has been going on 3 weeks or so, the negatives are all coming from maybe 4-5 individuals? I guess I would expect more overwhelming consensus if there was a problem.

Let’s just say, I know more people not on the forums then on the forums who ride on zwift. I’m just trying to get the word out. This will be my last comment on this issue, since it seems more people have a problem with people having a opinion on something….


So two things; starting with the latter portion of that.
It’s important to note the draft is much shorter than it was, so yes, once you clear about 1 bike length away from a rider in Zwift, you’re essentially out of the draft near completely (or close to); this is absolutely way different than prior before, and was I believe the biggest adjustment everyone had to make, was to not let slip behind anyone further than what they became comfortable with in PD4.

My commentary on that kind of goes back to my statement earlier that, there has to be a fine line between making Zwift too easy for people in the draft to where it’s more erring on the side of realism, versus making it closer to “equal” efforts for people in varying levels of draft.
Again, too easy, ala real world draft at these speeds, then people would complain that they aren’t getting any sort of workout when they can cruise at half the w/kg they think they should be for … in this example of a thread, Robo Partners…

If Zwift went for hyper realistic, it means with you and a handful of folks, could ride with the A partner, and having someone in the back riding at a D pace… this is an issue.

On the first bit of that, I kind of mentioned it earlier in this thread and I’ll repeat it until I’m blue in the face for sure; but I don’t know the real solution:
Auto-steering is absolutely imperfect, and definitely causing some real issues here and there.
I completely agree with you and know what you’re talking about.

There was a comment here or on another thread about someone saying they struggled to sweep someone because that person went into Coffee Break mode, and that rider got “stuck” in front of them in a pace-line manner, which meant that person was unable to sweep this Coffee-breaker; at least in terms of what power they would have needed to put down to sweep; was essentially raised by a large % due to that blocking.

I’m personally under the impression that PD4.1 isn’t really that problematic; it’s other systems that are causing it to be problematic under specific circumstances.

Is auto-steering part of PD? I have no idea, but I don’t consider it the same system; as steering occurs with or without anyone near you.

So while I haven’t really seen anyone tackle this topic and instead focus on PD itself, I do think it needs looking into, and possibly tweaked, just as PD4.1 was tweaked from PD4; to get finer results.

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Better to feather the brakes when needed rather than touching wheels with the folk ahead and crashing.

I prefer to ride alone on the mountainous courses in Zwift and leave group riding for real life. IRL is a lot more enjoyable for that.

This isn’t True…the draft is narrower left to right and a bit shorter but 1 bike length is about 2 meters which is the sweetspot for saving the most watts. To 5meters of Close the Gap draft is the same strength…and in a group there is more Draft then ever before so you can save more than in any previous Pack Dynamics :wink:

Ok everyone, settle down. I have some announcement to make and some kudos to give to those that persisted in complaining about a possible problem.

(irony)Because we at Zwift don’t care anymore about feedback from users…(/irony), I went on to search and double check for problems related with the complaints.

It turns out there is indeed a bug. Currently the progression inside the groups in PD 4.1 is harder than it should be. It’s like a game stuck in the hardest difficulty. And I assume the fault for it, it was a silly little mistake.

Why wasn’t it detected in all the testing before?

  • because it’s an issue related with information coming in the network, in the internal bots testing everything was fine because the bots run locally.
  • in the real test events it wasn’t very apparent because the field sizes were never very large. Rarely above 50, except probably in the ZI Tiny Races where regardless of the size it’s usually an all out race.

So, like it was reported by some, it becomes more perceptible in bigger fields, not because of any difference in the software but because when you are in a bigger pack everybody at the back starts panicking and accelerating to go to the front.

So there you go, case closed. Hopefully this will be fixed in version 1.49 (and at worst in 1.50)

EDIT: This is a general pack dynamics issue, not specifically tied with Robo Pacers.


Oh and by the way, the tips I gave above are still very much valid regardless of the problem or not.


Thank you for monitoring and following up, @DavidP .

The discussuon has gotten a bit heated which is unfortunate but I’m hopeful everyone will take a pause until we can observe the effects of the next update.

I started the thread as someone who never races but rides with the Cat-D Pacers (300km last week) and observed something seeming off. I deferred to the racers vis-a-vis their experience with PD4.1, and also note, yes, this issue seemed to be more acute with larger packs.

I’m relieved to learn the effects are not in my head, nor simply “something to get used to” but rather unintended.

I’ll be locking this thread momentarily and will unlock after the relevant update. EDIT - unlocked and updated.

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110 riders for me on tempus fugit, i haven’t done any other robo pacer rides recently though. i will try to slip another one in somewhere this week with a smaller pace group, but i’m basically an idiot so i’m not sure if i will have the vocabulary to describe what feels “off” about them anyway

edit: nevermind i did not read david’s post before replying. thanks for looking into it, i don’t use them a whole lot but i like that they’re there so it’s nice to have them working correctly whenever i do. cheers

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Thanks for the info David. When I came back to Zwift after summer I was quite shocked how hard it was to move in the pack or to even maintain a position. I was dropped on a flat part which usually does not happen.

I am happy to read that there is some more improvement to come. Racing is the reason I zwift. :slight_smile:


Thread re-opened - new pack dynamics are live.

Lol at all the people in this thread trying to convince us that the bug was actually intentional and we just needed to get used to the new PD.


I did a ToW event for an hour with ~320 riders and I thought the feeling of passing riders in a pack was more “normal” now but my question is whether PD4.1 is still meeting its objectives such as lower pack speed. How much of the PD4.1 change was effectively undone by this bug fix?