New Pack Dynamics [February 2021]

Read this thread.

I have been. I don’t see a downside to better synchronicity though.

I think the downsides are simply that it exposes physics issues that have been there, for the most part, for a long time.

It seems like better synchronicity is the natural first step. A bit pointless fixing anything else if that isn’t right first.

Now hopefully they can move on to the draft, sticky draft, accelerating pack speed, speed through corners etc. Wes stating that draft lock is a good thing is worrying though. It’s a workaround to cover up for other issues with the dynamics.

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It’s a workaround for some issues, but those are legitimate. We don’t have brakes to feather, so if we’re coming up behind someone and want to tuck in, there has to be a mechanism for that. So sometimes it’s a good thing and works in our favour.

The problem with sticky draft is it’s not intelligent, and too often works against our intentions and desires. That’s what they need to solve. The easiest* way would be to give us brakes and kill sticky draft off. :smiley:

* the technicalities of adding brakes notwithstanding, but they added steering via the Companion app. Just saying…

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I’d like to see some FutureWorks events with zero sticky draft. A pre-Watopia Zwifter posted that at first on Jarvis there was no draft lock at some point. They said that draft lock was not necessarily an improvement.

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That’s a very good point, I didn’t think about that. Otherwise if you want to sit behind them, you would often just speed past (as in real life without draft).

That said, should be an easy fix. My Neobike has brakes, so yes you can look to enable those (they are garbage though) but an easier way of managing it is is with power. If you drop off the power significantly it is clear you are intending to slow/sit in the draft.

Riders won’t risk that today, because the draft is not strong enough.

In real life the same power to get you to the draft would also get you past the draft, so there should never be an example where you are getting locked in by the draft and not passing as you should.


I sometimes get the idea that the “sticky draft” us determined by w/kg instead of speed.

A small rider get stuck behind a big rider if both are doing the same w/kg on flat roads and the opposite on climbs.

But this is just a guess.

I would be “a big rider” in this equation and my experience is the exact opposite: getting stuck on the flats, not on climbs (the punchy ones, anyway).

Another new look race done, this one wasn’t too bad presumably because of a smaller pack (not enough to split the pack sideways in the middle). I still saw others moving side to side way too much in front of me but my usual wheelsucking position at the back was stable in that respect. Staying in the draft definitely requires more attention but for racing I think that just makes things less boring.

My wishlist for an improved pack dynamics:

  • More finesse to sticky draft. As pointed out, the sticky draft mechanism must sense if we are slowing down to stay in the draft or hold constant power or accelerating and want to pass.
  • Fix too little draft in groups. I think I have seen that the new pack dynamics work better now in regards to keeping the group together, with the double draft enabled.
  • Fix too chaotic experience when the group is big. The start of races and group rides with many riders is a bit too chaotic for my taste. Riders are thrown left and right in front of you. The experience is much like playing an arcade game. I understand that one of the goals of the new pack dynamics was to improve the synchronicity of riders, but I don’t need that at e.g. at the start of the race. A more dynamic level of synchronicity would be good to improve the experience.

Spot on . I think others have commented before on the “gravitational” impact of going past a rider even if you are clearly sailing past . I can only anecdotally confirm that is my impression too , although I think this was one of the areas that moving sync to server has improved . What should happen is not this pull but in fact if anything what you should get is a marginal slingshot effect

Again spot on . I wonder if the issue could be down to how draft is stacked . At this level of detail only Zwift themselves would know but It could be that draft is a linear thing based on how close you are to the back of a single rider , any rider . The calculation is done purely on how your draft is to that one rider. However that is not how draft really works in pelotons . the drafting stacks and accumulates . That is why in really big groups you could even nearly free wheel at speeds you could never do solo without going full gas. This currently is impossible in zwift , if you step off the pedals even for a few seconds in zwift blobs you are very likely to be shelled out the back.

Your third point is also very true . I think this might take a lot more to work out , we could be talking about introducing a lot more rigourous collision detection here which I am definately not adverse to It was broght in with steering and appears to be possible iwthout causing impact , although it was only lateral collion detection not directional . It would add a lot more tactical realism to racing for sure and for that would be awesome .

Great wishlist though . gets a +1 from me.


Done a few events since this was introduced (lost a lot of time initially as my trainer was broken) and though it seems to work fine in smaller groups, once you get more than about 10-15 riders in the same general area the amount of sharp movements forwards, backwards and particularly side to side is quite nauseating. Based on what we know about the changes to the code - less client prediction and more actual position data - I assume this is because the game is putting them where the server is reporting them to be with more frequent and accurate data, but it means their immediate location is now more frequently clashing with where someone else is. So riders are forcibly pushed aside since they can’t occupy the same space, like trying to squeeze washing up bubbles together with your hands.

Feels like we’ve gone from ‘inaccurate’ but smooth, to accurate but erratic.


And there are other factors, too. Since the update, there seems to be an illogical left-hand bias to the virtual lanes. Worse still, when trying to ascertain any meaningful information from the rider tags that are at the bottom of the screen now results in immediate nausea for me. The tags are moving rapidly from side to side, conforming to the effect you describe, making the reading of the data contained on those tags nigh impossible for yours truly. This is especially annoying when in a large group ride with the Pace Partner, and slightly ahead, attempting to make judgements about the PP position in terms of distance astern, and rate of closure/opening. The PP makes frequent random lateral movements, and the PP’s tag (often obscured by other riders, the power graph, and turn indicators, is now complicated further by also jerking back and forth in tandem with the PP lane changes. Very unpleasant.


Hi @Dave_ZPCMR

I had some weird things with the new dynamics the I completely removed everything Zwift from the pc and started from scratch and things feel a lot better. I am not sure what changed or how it is possible but it helped. And I am on the latest launcher.

shudders :face_vomiting:

I may have to give it a try. Again. :wink:

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@Wes_Free That screenshot is a good illustration of some problems I have been trying to explain in words.

Picture vs 1000 words :wink:

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Just finished a race. My own rules after the new PD is: Stay away from the back for all costs - be in the front 10 if you can to get a less chaotic ride :roll_eyes:


I’ve been riding with pace partners a lot lately, as a sort of challenge to see how long I can hang on to the B train. This is both riding at or above threshold for me plus trying to master the draft.

I agree the new dynamics are very erratic, but I find that when a small group gets in front of the bot and strings out a little I can ride at tempo and stay in the group no problem, often having to fall back to stay in range of the bot.

In the pack however when we are all bunched up, a slight let up on the pedals and I’m flying backwards having to fight to stay on. In reality in this scenario it should be the easiest place to pedal.

Hopefully these adjustments are all part of Zwift working to perfect the experience, but I suspect they are not in a hurry!


I have also experienced this strange behavior. That is why I have found that it is easier to stay just behind the riders at the front. Much easier. It does not make sense, but it is consistent.


Having raced a few more times, including this week’s ZRL, I am still a little torn on the whole thing.

It definitely feels like an improvement overall - I wouldn’t want to go back to the old system, so that’s something. Bridging seems slightly easier and you can be more confident and controlled in when you are in the draft. Most of the frustrations have already been listed - weird lateral positioning (hugging a narrow channel at one side of the road), sharp unrealistic movements when the pack is more dense, and ‘coupling’ of riders in a lateral position. The last one is a particular issue in the TTT, where the draft can be lost despite being close enough to the rider in front, because it has moved you and the rider behind you to one side for no apparent reason.

The biggest issue for me still is that the slingshot effect is still there. You can surge to the front, stop pedaling as you realise you are hitting the front, and continue to accelerate the speed of the pack. It means that a large pack with no individuals doing any work still moves unrealistically fast. There needs to be a mechanism where you cannot move past the rider(s) at the front unless you are doing more work than them - as IRL - hit the wind and slow down.


Could it be that the Zwift is too slow with detecting that you have passed the front so that you still have the draft from the group a bit after?

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