Pack Dynamics 4 Release [April 2023]

it’s the last riders wheel not the first. think irl if you would hit that riders wheel.

If you are pushing an extra 220 watts every time you see a flash of red i’m not surprised you are going to get tired quick and yoyo around the pack. have you tried riding with your sauce window over the power to see how it feels when you aren’t looking for a red flash?

With only three riders (mostly in line rather than abreast) on a wide open road IRL he’d go past easily if he wanted to. It’s not like he’s barging through the middle of a pack of 20.

I thought everyone agreed sticky draft sucked, just calling it “pack dynamics” doesn’t make it any better.

Come on, even in real life if you exceed the riders wheel you know to peel to the right or left of that rider. This is wide road, unless my avatar is staring at his phone, you might just go 1/4 bike length next to the rider in front and fall back behind them.

And pushing 220 watts is about 2.6 w/kg. it isn’t a recovery for me, but for a split second to get up to speed isn’t consider an effort either.

i’'d agree so the question then comes how does autobraking deal with pack size if at all. e.g if peloton is less than n should you just get pushed sideways around the group and autobreaking does not apply at all unless a certain pack size is met?

Maybe it does or meant to but that would see a more logical approach

I got the impression that the original aim/claim was that it would only apply in a “high draft” situation which we might perhaps interpret as being behind a decent sized pack. If three spaced out riders is “high draft” then this description seems misleading to the point of meaningless.


There was one event in which I was repeatedly braked noodling around (about 30kph) with just me and one other rider.

@DavidP Here is a new video where I see issue with the autobraking. You can paste the 2nd part to youtube for viewing.


Issue starts at 41:05. I am midpack about to go 0 watts to coast.
41:15 I just coasted and drafting behind the 10/10 riders pushing about 190 watts to stay in draft.
41:19 I notice rider 1 pushing watts putting on distance. I am in draft pushing 150 watts. My draft on sauce showing 82 draft.

41:23 Auto brake starts happening, my wattage doesn’t drop. It flickers a few times, my draft bounce around 75-80 without gaining speed. My wattage has increase from 150 to 180. Distance to first rider expands.

41:29 Now I am pushing 230-240 watts to close the gap.

So there doesn’t seem to be any reason to trigger the auto-brake from the position I was in. And the cost was requiring a few extra seconds of above threshold work to counter the triggers.

The question is, is the auto brake there by design or is it a bug. If it is by design what objective was it trying to do?

I’ve got autobraking issue today with Stage 2 Beach Party race (event id: 3749608).

What I’ve seen:

I was in the back 1/3 of the field. At some point I’ve eased for a second, looked down, and when I looked back at screen the field was at least 10 meters ahead of me. I was not able to catch them (as I’m mid-C rider). It cost me about 10 places and a lot of fun.

What Garmin Connects tells me:

It happened on a flat section of the race (elevation is constant 15m for duration of what I’m describing).

At 11:56 I’m doing 241W and going with speed of 38.2km/h
At 11:58 I’m doing 205W and going with speed of 36.9km/h
At 12:00 I’m doing 156W and going with speed of 26.9km/h.

It looks like too much braking was going on, no matter how much I eased of, especially as the elevation was constant, no incline yet.

Were you seeing your power numbers flashing red on the game display? If not then it probably wasn’t the autobraking feature at work.

It’s impossible to evaluate what you’re saying with the information provided. Autobraking happens when you drop power while going faster than a rider in front of you. In my experience it’s not very significant. I ignore the flashing red numbers and nothing really happens. But I don’t apply power while in a group or chasing into a group a group and then drop off power suddenly. Autobraking will be more likely to occur if you do that. Autobraking is mostly avoided by riding with steady power.

Unfortunately I was not looking at a screen for one or two second, so I cannot confirm red watts. I have seen them plenty of time in my life, but mostly when I was in front of the pack.

The only thing I know is that I was easing power when riding at the end of the pack on a flat section (this is what Garmin Connect shows) and I lost 10km/h in 2 seconds. I expect to lose some speed and few places by not putting steady power, but 10km/h less is too much on flat ground.

On previous lap I had very similar power drop but no speed lost. Maybe looking at my tcx/gpx file of that ride would help?

One hypotesis:
If I was at the very end of the pack, then dropping power got me from high-draft to low-draft situation, and that caused autobraking?

Are you using Zwift Play Controllers?

You nailed it. This is exactly the reason hanging on to a fast moving group is much harder with PD4 than it was with PD3. This doesn’t happen as much in the pack, that’s why a lot of people here say that they never notice autobraking. In the back of the pack however, you can easily lose the draft because auto steering can just shove you to the side.

@DejanPresen yes, I’m using Zwift Play Controllers. No, I was not braking.

@_Geralt_of_Rivia If my hypotesis is true, it should be testable. I’ll try to reproduce this issue sometime next week with pace partners ride. It should be easy to get into D pacer on flat Tempus Fugit and check it that can be done intentionally. If I get more occurences of that behavior, I’ll record them.

Let’s get the facts…you were not watching your screen for 2 seconds and you are sure it’s autobraking from PD4 fault for slowing you down…meanwhile you are using Zwift Play that has braking.
Do you have any video of this?

I used Zwift Play in a race only once and i hit brake 3 times by mistake while shifting.

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Would it be possible to (optionally?) turn off auto-braking for Zwift play users?

In any case, I find the auto-braking really bad. E.g. often times when there is an attack and I move through the field, if I ease off a tiny bit, I will get auto-braked with tons of people still ahead of me.

Or get auto-breaked as we reach a small incline where I would not hit the front anyway.

Honestly, almost every time the game brakes for me, I have to immediately kick in more watts to not lose ground.

It might be related to my riding style - but getting ‚punished‘ for easing off to deliberately control your pack position is non-sensical.

Conversely, there are also many cases where I brake myself where auto-braking did NOT kick in oO

I’m puzzled by your experience. Not saying it’s wrong but it doesn’t match my experience with auto-braking. I ride as steady as I can but I do routinely back off to avoid the front of the group. My perception is it’s better to be occasionally auto-braked than to ride on the front, especially if I don’t want to encourage the group to speed up. The effect seems really small and if I never saw the red numbers flash I wouldn’t know it was happening.

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You will love PD4.1…try it :smiley:
There are many races already using it

Racing today, got hit by the autobrake in several inappropriate times. Have a video screenshot of a couple, converting to GIF makes them 70mb instead of 4mb so too big to upload here.

One instance: mid-pack, on the side, terrain goes down so power goes down despite cadence staying the same, at the same time sharp curve so due to how the draft cone rotates dropped out of draft, braked.

Another instance: mid-front pack, terrain goes down so power goes down, braked.

Since the 4.1 algorithm eliminates the free speed from churn it would really be great if the autobrake algorithm could be removed entirely from 4.1

Why didn’t you post this in PD 4.1 Topic…i think i agree that it’s almost not needed.

Because last time I commented about the autobrake misbehaving in the 4.1 thread @Gerrie_Delport_ODZ moved my posts to this thread because it wasn’t happening in a 4.1 event.

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