Fix Drafting

I’ve recently participated in a couple of races which have left me particularly frustrated with the way drafting is implemented in Zwift. While I understand that Zwift is a game, it is also supposed to imerse us in a life-like riding experience, and the current drafting algorithm is a constant reminder that we are not really riding.

The standard draft, we have learned, is something like 50% of reality, and includes “stickyness” to help riders stay together. I can see how this approach might have some benefits in social riding, but it is nothing but annoying in a race as you continually get “stuck” to slower riders and have to drasticly increase power to break free. Each of those efforts burns a match that you would not need to use IRL, and eventually you run out of matches.

Recently we have seen the introduction of Double Draft/Real Draft/True Draft, but this also bears little resemblance to drafting in real life. Riding a flat road in the middle of a large pack of riders at 35-40 kph I should be able to hold my position soft pedaling at less than 100 watts. In Zwift I have to keep the power at 250-300 watts or I’m quickly out the back of the peloton.

Can drafting in Zwift please be made more like real life? Perhaps at least for racing?

  1. Change or remove stickyness.

    Stickiness should only apply if the rider behind would be going slower than the rider ahead in the absence of any draft. If the rider behind puts in just enough more watts that they would be moving faster than the rider ahead (in the absence of any draft) they should gradually move on by.

    The strength of stickiness should also decrease as the draft effect decreases. If the draft effect drops below a reasonable threshold (say, 5 watts benefit) then stickiness should go to zero. When riding up a steep slope at 8 kph I should not get stuck to other riders.

    This archived post contains a link to a video showing what should NOT happen. (Video by Wes Salmon, no less.)
    https://forums.zwift.com/t/draft-stick-bad-for-racing-group-rides/7988

    Better yet, just get rid of stickiness and make the draft more realistic.

  2. Make the draft uniform across the road.

    Since we have no control over our lateral position, make the draft dependent only on our distance behind the riders ahead. If the Zwift application decides to move our avatar left or right we should not suffer the consequence of getting kicked out of the draft. So make the draft equal across the width of the road. Or give us some left/right control over our avatars.

  3. Make the draft global.

    At the moment, the draft seems to be tied to a single rider ahead. Even in a large, dense blob the “Close the Gap” message is popping up every few seconds and my avatar keeps moving between the drops and the hoods. There is no way the draft benefit I’m getting should be changing like that simply because a rider ahead in the pack moved 12 inches forward/back or left/right.

  4. Increase the strength of the group draft.

    The strength of the draft in a large group is far too low. If I’m in the middle of a pack, I should be able to keep my position while getting some recovery time. If I hammer to catch a group up the road, when I catch them there should be immediate relief and the opportunity to sit on the back and get the lactic acid out of my legs. In the current drafting algorithms, even DoubleDraft, there’s not enough draft benefit to recover.

    The study below has been linked before, but I’ll include it here for reference.

https://www.sciencedirect.com/science/article/pii/S0167610518303751


The numbers are the drag force as a percentage of the drag force of an isolated cyclist riding at the same speed.

I have mixed feelings about changing the drafting in Zwift. I have the same problems as you, with the standard drafting where I have to apply an unrealistic amount of power to break out from the sticky rider. I really like the double draft, which is more like IRL but at the same time makes it easier to stay I the draft till the sprint. I’m having racing in mind here. I have too often stayed in the draft till the end myself, and it can seem a bit unfair to take the sprint without having to do any real work.
Most races on Zwift are short for a reason. It is not very comfortable to ride fixed to the trainer for too long. So the action has to happen in a short amount of time.
If the race is flat as well, there are not many opportunities to break away. If we would get even more effect of the draft, even if it is more like IRL, the race would be boring and predictable. On the other side, I find myself selecting the double draft races since I will have greater chances to stay with the front of the group till the sprint :thinking:
For free rides, these reflections do not nessesary apply.

2 Likes
  1. Remove stickyness. Yes!
  2. Ignore lateral position for draft. Yes!
  3. Make the draft global within the peloton. Yes!
  4. Increase the strength of the group draft. Yes!
6 Likes

I hear what you are saying. But if Zwift is supposed to be realistic, let’s make it that way.

In real life, it’s difficult for a breakaway to succeed on a flat course. Races on the flats tend to keep the peloton together, and that’s where sprinters get to shine. Maybe there’s a break with five or ten riders that manages to keep away from the main pack, and a realistic draft will help with that. In real life or Zwift, spriniters and heavier riders are going to seek out and enter races on flat-ish courses.

The current drafting algorithm in Zwift makes every flat-ish race more like a time trial.

If you’re a lighter rider or a hill climbing specialist, you’re probably going to look to compete on hilly or mountainous courses where in Zwift - as in real life - the sprinters are left far behind and you can fight it out with other climbers.

There are plenty of races on a variety of courses to choose from every week in Zwift. Riders are free to choose the ones they like and in which they think they will be most successful.

1 Like

I hear what you are saying too, but if most of the riders can stay with the group till the sprint, we could just as well have arranged 2km races where the best sprinter would win. Kind of boring i.m.o.
I think the current approach, where the race organizer can choose the drafting algorithm is the way to go. There should maybe be more algorithms to choose from, like a more real-life drafting as you describe, a TT algorithm, etc. This is where Zwift can apply some gamification to the experience.

Hi Bhaltair,
I think all your points are good.
I’ve been on about removing stickiness especially on the hills.

It makes no sense to bridge a gap to the next rider only to get
stuck or to have to power up to break the stickiness. I may only
going slightly faster than the rider ahead but I feel I should just
slowly slip past without any extra effort. Total nightmare on a
long climb having to power up when I’m probably at my max
anyway.

On point 2 I’d like to be able to move to the side of a rider to
avoid getting stuck. Maybe that could be achieved by using
the companion app? Pressing a button move left or move right.

Point 3, I agree with your point here I hadn’t noticed that.
I’d also like to get rid of "close the gap"message or have
the ability to go into setting and disable it.

Point 4, It could be good to increase drafting in the pack.
Maybe it would give more riders the chance to rest then
make a break. With repeated rests and attacks perhaps
one of the breaks would stay away?

The stickiness and drafting defiantly need changing.

Cheers “Ride On”

4 Likes

I am brand new to this, first 3 races i couldn’t understand why i couldn’t feel the draft.
extremely disappointed with zwift… feels nothing like real riding.
I went all out on the tacx neo 2t.

it has nowhere to fine tune watts, drafting etc

i am a cat 1 rider and i cant keep up with a c group race?

i will change it for a wahoo my friends say its better.

To bad no one from zwift is replying on these great ideas of youres to improve draft

Good post! IRL in a group draft it is easy, sort of sucked along, soft pedaling. Not in Zwift, it is TT mode to stay with the group. Zwift is a good platform, but it is developing most riders into TT riders - lol.

2 Likes

Hi @Rodolfo_Aguilar

welcome to the forum.

It takes a bit of time to get used to racing in Zwift, it is different to road racing. You wont “feel” the draft, but once you are in a bunch you can reduce your power and still stay with the group.

Racing in Zwift can be a lot of fun.

1 Like

Yeah its fun and good training but its NOTHING like real riding.

If everybody os complaining about the draft being so un realist why not fix it? instead of asking people to test and test?

Iv done all the tests add in this forum but still its nothing like reality.

Really wish you could fix this especially now that nobody can go outside to ride in a group.

If i come up into a big group i should expect to feel 40% less wattage and of i dont i should zoom past the group. None of these happen.

I find that the wattage I need to put out in a group IS less than if I’m on my own, or at the front of the group. I’m not sure if it’s 40% less, but it’s definitely less. What I find unrealistic about the draft is that groups seem to travel at a higher pace than they would IRL, and the larger the group the more this is magnified. When in the group this isn’t necessarily a huge deal, but when you get dropped the power output needed to catch back on is significantly higher than IRL, which is crazy.

3 Likes

Alsoi in the downhill im pedaling at 300w and draftinh going down 7%… thats ridiculos IRL i should even have to pedal.

Get the programers on a BIKE!

1 Like

Well @Rodolfo_Aguilar , better if you don’t expect any as IRL in terms of physics or performance.

Also you can say @Gerrie_Delport, what is your experiencie IRL, for example on flat terrain…

I said physics are not realistic, for example we see that considering 2 different riders in Zwift:
60kg @ 236w = 38.5km/h
80kg @ 327w = 41km/h

Or a rider who is 60kg @250W, can be as fast as a 80kg @300W rider.

What do you think?

1 Like

Yup i left Zwift a while ago… i got frustrated with the programers. Everybodys asking them to fix the issues and make it more realistic but instead of making it better all i get are excuses.

Switched to RGT cycling wich has a much better drafting algo, also you can fly on the downhills without much effort. I think they nailed it much better than zwift.

No im seeing the TOUR (virtual) on the tely, i think they fixed all these problems for the pros, you can watch them stop pedaling on the downhills and they are still flying, you can also compare watts when they are in the peloton and figure they nailed the drafting algo. So im pretty sure it can be done right. I jiust dont understand why they dont do it for the mortals on zwift?

Im not comming back to zwift until they fix it.
I hope they do especially now in Covid times

2 Likes

To add to this, they should add corning physics to the draft/speed algorithms. A large group descending hairpins should not be doing 80km/ph! Riders should be slowed through corners, and larger groups slowed even more. This means an attack over the crest of a climb can be sustained, like in real life. At the moment it is pointless pushing hard on a climb when the pack behind will swallow you up at ridiculous speeds on the descents. RGT slows you through corners and the overall physics model is far more realistic.

6 Likes

I would say that it’s not perfect but it’s pretty close to doing a UCI race. Averaging 30ish MPH on the flats. A little less if there is some good climbing. If you get dropped you’re not coming back. If you sit in the draft you can nearly get pulled along all day. Maybe there isn’t enough headwind or their virtual CdA is too low since there is no wind.

The speed of a pack might be reasonably close to reality. But I’ve got to disagree that the draft in a Zwift peloton will ever pull you along, even at 30 MPH. Zwift’s group draft is not even close to the strength it is in real life.

Or are you saying that IRL you can sit in the draft and nearly get pulled along? That, I’d agree with!

Try a race on RGT Cycling and see what you think of their group draft physics.

Agree with the draft being off. There’s never a breakaway with pack speeds.I would accept a few draft experimental races. Try cutting the draft down. Double draft, I feel, has been a bit of a disaster.

What do you think of the RGT draft physics? They do have a power penalty for moving up thru the pack which is clearly more realistic. They also have defined lateral position (on Zwift it’s improvised by the client) so if you’re @ the edge you might get less draft. But I’ve never used it except for a brief experiment riding solo (ride suddenly terminated when I tried to switch to my music app).

2 Likes

That would seem the logical solution, right? But it doesn’t seem to work. The default Zwift draft is already cut down to 50% - apparently it’s 50% of a single rider. Every Zwift race is basically a TT. And I agree that Double Draft only makes things worse, and the group draft is still way too weak.

Have a look at this race on RGT where the group draft is MUCH stronger.

https://www.youtube.com/watch?v=LEcTa0FVY4U

A three rider break forms at about 9:50, and stays away to the finish.