Pack Dynamics Testing (from 29th October onwards)

Please use this post to provide your feedback on Pack Dynamics.

For group rides, we are looking for feedback about how you move around in the group and how the draft feels, including getting back into the group.

For races we are looking for information on the above but also about an attempted breakaways!

We are testing on
Pack’s Thursday Social PACK Social + KOM After Party - The at Home Cycling & Running Virtual Training App
Pack’s Saturday SUB2 PACK SUB2 Saturday + KOM After Party - The at Home Cycling & Running Virtual Training App
Herd’s Doughnut Ride The HERD Saturday Doughnut Ride - The at Home Cycling & Running Virtual Training App
Herd’s Sunday Endurance Ride The HERD Sunday Endurance - The at Home Cycling & Running Virtual Training App
3R’s Wednesday True2 Steady Ride 3R True2 Steady Ride [2.0w/kg avg] - The at Home Cycling & Running Virtual Training App
HISP’s Los AvHISPados Los AvHISPados - The at Home Cycling & Running Virtual Training App
3R’s Wednesday Endurance Ride 3R Endurance Ride - The at Home Cycling & Running Virtual Training App

The group rides are from next week onwards and I’ll update links once they are available.

Hi James,
Just curious if it is possible to turn on the new PD for certain pace partners… sorry robo whatevers… that’s a dumb name, they will be known as pace partners forever I’m afraid. I’m guessing not because they are “free riding” all around Watopia and that would require a full switch over to the new PD.

However, what about on Makuri for a few days when it isn’t in the normal world rotation? Could we test the new PD then?

Hi Mike,

I’ve already checked in on this. I* can’t turn it on for Pace Partners (4eva) but I can turn it on for specific worlds. We will probably do a Makuri test at some stage.

*When I say I, I mean someone else who can actually do those sort of things


Edit: can we have a Robocop costume next year for Halloween pretty please :pleading_face:


Only if you follow the Prime Directives.


Initial reaction from Tiny Race Series A cat - Idea is good, execution not so much

The draft have almost been reversed, in that it is now way easier to stay at the top 20-30 riders instead of sitting in the last third of the pack. We saw guys being dropped at +6 w/kg while a relatively light guy like me was chilling at 4 w/kg in the front. Being at the back felt like the draft either wasn’t there or you got caugt in sticky draft from guys doing way less than you were doing, and when you got free you shot up 10-15 places instead of moving smoothly

The tiny races are not the best place to test them with so many guys and race two being more effected by bike choice than pd4, so might work better in longer races with proper breaks. However as is i would expect that the only thing that would happen is that everyone will be fighting to stay at the front, bringing the blob speed up, negating the desired effect from pd4 of slowing the blob down.

Ideally i would think that pd4 should make it so that staying at the back is the same as staying further forward, and it then being harder to move forward, not just harder to stay with the group. And this should be done without using sticky draft where you have no idea when its going to hit you.


If we’re going to test it properly, please can we at least get the events set up correctly. I’ve had a lot of patience with the numerous errors with ZRL and team private events, however, this is getting beyond a joke.

Setting events up correctly should not be difficult and we shouldn’t be having issues in almost 1/3rd of the major races.

Your marquee events or test events like this should have what they are promised and advertised as. Having all powerups enabled on a single banner 130+ person field with a flat finish is stupid.


PD4 in the Tiny Races was different, but not altogether positive. There was less front-to-back movement in the pack which seems more realistic but the draft didn’t feel ‘right’.

In the pack the draft felt relatively similar to before but as soon as you got close to the back (so still in theory with plenty of draft IRL) it all became much harder to hold on. Small groups of 4-5 riders didn’t seem much faster than a single rider.

I feel like there are other things that could be improved before pack dynamics is ‘fixed’. For example:

  1. Introduce braking in all corners (not just downhills), with less braking required for riders at the front of the group than the back.
  2. Change the resistance of trainers according to gradient and draft, rather than just gradient.

Now the rant is out of the way. Whether it’s intentional or not, it is far harder to keep with a pack when at the back than near the front.

This is the exact opposite of the current pack dynamics where you can do less at the back. I had suspicions of this from the trial and after a bit of playing around with it today, it seems fairly clear this was going on. People towards the back, doing 8W/Kg with an Aero on flats, we’re still going backwards vs riders doing 3 W/Kg in the pack.

When I was on the front row, I was maintaining postion doing 1 W/Kg less at the same speed as when I was towards the back. It seems like some kind of sticky draft has been reintroduced.

Also, while again, not a great place to test it, breakaways were far less effective than the previous test event. On the dirt downhill (race 1), most riders in Cat B were doing 3-3.5 W/kg. The occasional solo rider at the front doing 4.5-5. Breaking away at 6-8 W/Kg gained me 2 seconds. In the previous test event similar numbers gained an 11s gap over a similar amount of time at similar group speeds?

The first test event showed a lot of promise for PD4. Racing now shows that it’s one step forward, two steps back in its current setup. It also different between races, especially race 4, which will be very disappointing if it was.

Unless there is actually an error (which I’m not aware of) these events are set up at Eric’s rewuest.

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This was the first race used in the test - didn’t expect it to be perfect and I’ve said a few times that we’ll tweak things if we need to.


All powerups enabled in race 4 instead of feather?

Yeah I get that, just wanted to out thought down quickly while I had time. I realise that there’s still a lot of tweaking to do any you guys are willing to do that.

My main frustrations with it are that PD4 acts so differently in different situations on the road and don’t make much logical sense at times. Speeds on the dirt downhill (race 1) were faster than on the flats afterwards which is the opposite of normal. Riders would do 6 W/Kg and go backwards, whereas other riders would do 6 W/Kg and fly through the group. The inconsistency is concerning and lead to a lot of comments in the race.

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This reflects my experience in today’s Tiny Races as well.

Will check it out, cheers.

We’ve had some contractors helping out with event changes and they may have not been familiar with custom power ups (they are complicated).

I’ll ask Eric to send direct to me in the future.

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More than willing to make it as good as we can!

Really do appreciate the feedback.

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First question, was double draft enabled for the Tiny Races?

Onto my thoughts

Cat B - Tiny Races

Race 1 - Seaside Sprint finishing in the volcano

Started fast and stayed that way. You needed to be doing 4w/kg to stay with the group.

Race 2 - Road to Sky finish at the base of the climb

I chose the gravel bike and knew I had to push the start to avoid getting dropped and then I could use the gravel to my advantage. Coming over the hill at the start I was in the top 10 and all was going according to plan. Then someone blasted past and before I knew it 100 people had passed me and I couldn’t catch the draft. It was at this point that I thought something is off with PD4. I gave up and just rolled in the rest of the race.

Race 3 - The 6 Train rev

Right from the start people were slowly getting dropped out the back. Much like the first race this was just a relentless full gas effort to try to stay with the lead group.

Race 4 - London Classique Reverse

A slow start had people wondering if PD4 was active. We trundled along the river side doing 3w/kg until the rise. Full gas up the rise kept me with the leaders over the top. The pack splits up on this rise but usually comes back together on the downhill but with PD4 this didn’t happen. Still, I was struggling to stay with the leaders and got dropped as we turned onto Constitution Hill.

Then something really funny happened.

I dropped down to 3w/kg expecting to crawl to the finish while the riders rode off into the distance. Just like they always do. But a few seconds later I could still see the leaders and I was actually gaining. A quick sprint and I was back in the lead group. After the U-turn I got dropped for the final time.


There is something really weird with the pack drafting in PD4. It feels like, if you have lower w/kg than those around you that you get pushed to the back of the pack and you seem to lose any draft (like what happened in Race 2 to me). Too many times I was at the back pushing over 4w/kg and still dropped off the back.

The funny thing that happened at the end of race 4 was very bizarre. To get dropped, reduce the w/kg and then start gaining on the lead pack was very weird. It’s almost like when I was riding in the pack there is actually a greater amount of drag applied than if I was riding solo.

I get the feeling that PD4 is increasing the aero drag if you are in a pack and you are not pushing more w/kg than everyone else. This led to packs where everyone is pushing high w/kg just to avoid getting pushed out the back.

If this is the future of Zwift racing then I can’t see myself being a part of it. If you are in the bottom half of a category then you need to rely on the pack draft to stay with the leaders. PD4 seems to punish those people who trying to hang on at the back of the pack because they don’t have the w/kg to ride at the front.


I was also in the Tiny Races this morning…it felt like race 4 was using PD3 as it was much easier to move around and at the back of the pack. And yeah i got XP points at the only banner…lucky me.

About PD4 i noticed a lot of speed changes…it’s like if you are in 1st row of the pack riders are pushing you and you do less W/kg for the same speed…but at the back of the pack it’s like you can hit someone’s wheel and your speed drops for 4km/h and you have to push for 10sec to get the speed back up.

If you want to check the races from a double view…Zwift Insider Tiny Races - 4 Races with Pack Dynamics 4.0 - YouTube

My sentiments exactly. Hopefully it will be improved, but I had high expectations for CE when that was introduced too :roll_eyes:

Haven’t tried the new one out myself yet, but this is how I have experienced drafting already with PD 3. It’s very noticeable e.g. with the pace partners in that it is a lot easier to hang towards the front of the blob (sometimes a lot in front of the PP) than at the back.