New Pack Dynamics [February 2021]

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?

1 Like

Im not exactly sure increasing drag or something similar to it of the front is the way to combat the high pack speed, since several other factors play a large role in keeping the speed high. Without loss of speed in cornering or the ability of other riders to slow you down outside of sticky draft, ie its pretty easy to move around in the peleton, the natural speed will be a lot higher than normal. Setting up some sort of penalty to offset these could lead to it being even harder to actually attack and stay clear since whatever penalty applied for moving past the front of the peleton also applies for attackers be it solo or smaller groups.

There definitely is a problem with the churning of riders in the front, but without actually having solid riders and steering required to move around the peleton, the options are pretty limited. Changing it could very likely make it worse or have consequenses that just moves the problem instead of fixing it

Could well be, but in theory that position is being calculated much more frequently now.

I agree it shouldn’t be a penalty, but there needs to be something that stops you going past the front of the pack at little or zero watts. Breakaways are pretty simple - you should be able to get away if you are putting out more power than the front of the chasing pack. The chasing pack has an advantage because they can takes turns doing pulls. If they don’t organise that, then they won’t catch back on. At the moment no-one in the pack needs to do any deliberate pulls and they will catch a breakway anyway in most scenarios.


Im sorry but thats not true for IRL, and applying it to zwift makes absolutely zero sense.

IRL you will see a higher speed in a peleton vs breakaways even if no one at the front of the peloton is putting out more power. Why, because as long as there are several riders/team putting out enough power to overtake other riders in the peloton, there is also a churn of riders there. Try looking at the last 10 k of a sprint stage or a non technical descent, and you will see this exact phenomena outside, where the effort required to get to the front and drive the speed up is pretty low, but the effort required to stay in the front is a lot higher.

Even if we take riders who are identical and putting out identical wattage. The rider who has someone sitting behind him actually goes faster because of the changed windturbulence caused by that extra rider. cyclingtips. com/2017/10/much-benefit-really-get-drafting/"

Then there is the discussion of what is “more power”. Raw wattage has a much larger effect on flat or downhill sections, where w/kg means more going up steep climbs. Then there are height differences which affect cda, and speed as well so determining who is putting out more power is a very difficult thing and basically just describes the whole algorithm used to calculate rider speed anyways.

I agree with the aerodynamic effect of having riders behind you, but thought that might complicate the discussion. I said rider power to keep it simple, but really I mean rider speed (calculated from all of the elements that you mentioned).

I basically agree with all of your points, but it doesn’t change the core part of my point. You say it makes zero sense to apply this to real life, but this is exactly what RGT does, and it works really well.

1 Like

I havent used RGT so, im not sure what they are doing differently, but know that the some sort of brake are applied before corners, and would guess its that feature that is used as well if you say it works there. And if they have gotten it to work it might be possibly to zwift as well, but im guessing it would require a complete change in the way zwift works right now. I think that with the way its currently set up the the things i describe above would be problematic but hopefully RGT and others can push Zwift to find some sort of fix for some of the problems, because right now the control they have on the market makes these changes unlikely.

It’s probably just me, but my feeling is that ‘something’ has changed in the last week or 2. When Zwift rolled out the update a month or so ago, I almost immediately felt that group dynamics were much improved - EG there was far less of the ‘Yo Yo’ effect & it was far easier to hold position within a group (both medium size circa 30 riders & large >200 riders). Yes there was the rather strange swerving to avoid passing directly through riders when you are moving up but that was OK.
However in the last couple of weeks it feels to me like we are almost back to square one - the draft seems to be stickier than ever. I tried experimenting a little today in a group ride & it now seems you have to put out significantly higher power than riders around you to move up the group. Then you tend to go flying forward, as a consequence back right off, which leads to riders behind flying past, meaning you have to put the hammer down to catch back on, meaning you fly off the front… and so it goes on.
Nothing has changed my end. Same Power source, same bike/drive chain/network connection etc.
Am I alone in thinking the group dynamics have deteriorated in the last couple of weeks?

I have experience the same. It is really hard to get the power right to move to the front and stay there. I have found that the clue is to be aware when you have reached the front and ease off a bit. Don’t ease off as much as you think. When you see riders coming up beside you, push a little to stay in the front.
I don’t think that has changed lately, but I’m still learning how to ride with the new pack dynamics.

I guess there is no easy answer to the problem. The Zwift game cannot know what riders intentions are, it can only make assumptions based on a few parameters like rider power & speed relative the power & speed of other riders close by. It’s can’t really know that (eg) you intend to pull slowly alongside another rider rather than “sit on the wheels”. My feeling is at the moment the draft is too ‘sticky’, but I guess it’s designed to give newer riders a better experience, rather than try to emulate real life group riding. My main point is that I suspect Zwift are still tinkering with group dynamics. Somebody tell me I’m wrong!

This is a question for @shooj. The feedback will be better if we know what is going on with this feature. Are you still tuning this server side?

Worth remembering that a lot of the dynamics is NOT done server side .
That was one of the biggest problems as I understood it and one of the changes was in fact to just move some of it to server side , and for sure now making any diagnosis and/or analysis here even more complex.

So when someone says . Its doing something today it didn’t do yesterday .
It could be because they changed the server dynamics , or it could equally just be a local change on there PC,network or environment .

I’m 66kg and “almost B” I use a kickr core and apple TV, BT HRM is it posdible the lighter riders have been penalised more by the new dynamics? I have to produce much higher w/kg to even stay with other heavier C cat riders regardless of terrain or draft, I’ve even been dropped producing over 3.2w/kg with other heavier C cat riders averaging under 3? I know other lighter riders with the same issue?

I think this is an effect independent of weight. I’m on the heavier side of you and find that it got harder to stay at the back of the group. Gaps form more easily and people get dropped. This might be because riders are jumping more sideways now and leave others suddenly without draft. It could also be that, since they now try to prevent riders to ride through each other, it will now not place you in the draft of a rider if he is close to overlapp with you. The old algorithm seemed to let the riders seek the draft more often.

Is the revised data polling rate the reason everyone else in the pens seems to be restarting their turbo trainer animation over and over?

I was racing London Classique yesterday. On the wide red tarmac road, the group was split at the front for no good reason. I was slingshot out of the group and could not join the main group. It took a while before others started to join me and we were two groups for a while. This behavior was repeated every lap. I also saw others that were thrown far off to the side. Very unnatural and annoying. This needs improving.

Some weird draft going on today during the TTT. It felt like we did not have any draft at some times and our riders would duck out of the draft not staying in line.

1 Like

I’ve noticed that in pace partner rides I have to unpair the steering on kickr bike or I get pushed off to the side of the group and get no draft. Then you cannot use the steering to get the draft either.

If a ride has steering disabled then it’s a big problem too. You get pushed to the side and no draft.

And yet p

And yet people claim that people using steering have an unfair advantage. Really, Zwift steering is an unreasonable disadvantage in most situations.

The only advantage is riding on your own and being able to go right to the side of the road and prevent others from getting a draft. You can cut corners a bit too but most of the time it’s not that useful.