Help me understand drafting in zwift

Racing
1

For the life of me I can’t figure out drafting in Zwift and find myself off the back most of the time. For example the flat is fast series, my watts per kg shouldn’t matter when being considered a part of the peloton but it has a strong tendency to do so.

Here is an example:
zwiftpower event id: 3362510

I finished 3 minutes off the back in 32nd place of 35, averaging 260w which should have placed me in the middle of the pack, watt for watt.

Compare to real life:
Strava activity number: 7669123393

I got a pack finish of 36th of 74, averaging 200w. I sat in the whole time and didn’t find good positioning for the field sprint.

2

While watts is a big factor on a flat course w/kg is also a big factor whatever you do. Generally i’d say if you are 30kg heavier that others in the peloton you would still need to push 0.1-0.2 less that other others to keep up. You were 2.795 to most riders 3.1 or above 20 mins power today (at 95%)

I assume you are cat enforced into B but still a C on ZP was likely to be towards the bottom end of the Bs in terms of w/kg.

In terms of could you have done more to save draft it’s very hard to tell without fan viewing and the other key point is knowing when the surges come on the course to predict when you have to push a bit more.

You have one stand out effort from the 8th of January where you did 3.4 for 20 mintues that is likely to have pushed you in B but unless you can maintain that performance in most races B cat will be a struggle.

If you go to your feed page and more info down the right it gives you a bit more detail on your cat enforced figures is could be that you’ll drop back to C as CE only looks at 60 days history.

3

Draft in Zwift increases the more riders that you are behind but the number of riders appears to be capped, so if you are in a very big and closely-packed group you’ll find being behind 8 riders gives the same draft benefit as being behind 10 or 12. This means that many riders are all getting a similar benefit and having to put out a similar effort. If you are nearer the back and a gap opens a couple of riders ahead (and that you might not be able to see) then you’ll get less draft benefit.

Then there is something often called “the churn” which causes the pack to go faster than it really should. We can’t crash, we don’t have brakes and in big groups our avatars will overlap and pass through each other. If riders nearing the front are backing off and riders a few rows back are pushing on (because they have to as everyone a few rows back gets the same draft benefit) then those a few rows back often find themselves going to the front by passing through the riders dropping back. This sustains the high group speed. If a rider backs off the power at the wrong time then they will find themselves at the front, no draft, lower power than the group and decelerating rapidly - if they are not careful they shoot out the back and have to sprint to get back on.

Once you lose the lead group, which often happens when things kick-off on quite gentle climbs, it is very very hard to get back on. You’ll average a similar power to the lead group but never see them again as the churn keeps their speed high.

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4

Make sure that you are not using the TT bike in game.

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5

It looks like in this instance most people are around 70kg, whereas I’m pushing 90kg this winter. I’m 199cm, and the leanest I have been in the past year is 85kg. I don’t really expect to have to do a threshold level effort for an event duration to draft in a peloton. ZPower seems weird for things, as far as category enforcement goes, I’m probably a solid B with a 329w/89kg ai ftp from trainerroad.

This is very helpful. I have found myself in packs, but I find myself spit out quickly. The churn is the animal I need to really learn.

6

If the pack is generally moving at an even pace (not climbing or descending), a general technique to keep with the pack that often works well is this:

From In The Pack: downshift, but keep your RPMs high, to the point that you are slowly making your way through the pack towards the front. Because of the draft, you can be moving forward in a lower gear while putting out a lot less wattage than the people on the front. What you’ll find is that other riders from the middle of the pack will also be hitting the front. But you don’t want to be on the front, you want to be a rank or two back :slight_smile: So you want to drop back. But not too far back or you’ll get shot out the back. However, when you hit the front, you’re still in that easier gear and benefiting from drafting. So…when you hit the front, or slightly before you hit the front, shift to a higher gear, and starting putting in some more watts. Not enough that you go off the front–but amp it up a little. What you’ll find is that you start sliding back into the pack again…even though your own wattage is up a little. Because those people behind are drafting and moving forward past you. Eventually, your higher wattage will combine with the draft you’re now getting again, and your backwards movement will slow down. When that happens…shift down again to an easier gear. You’ll start to slide forward again. Rinse and repeat.

The overall effect is like there’s a delay happening in the bunch when you change your own wattage.

So the summary is:
Lower (easier) gear, higher RPM but keep the wattage low enough so you are just moving forward in the pack.
When you hit the front, shift to a higher gear, slightly increase wattage. Do it right and you’ll start to slip backwards, but not very fast.
When you stop slipping backwards, shift to an easier gear and spin faster again. Do it right, you’ll start to slip forwards again.
Repeat.

Importantly, downshift before or just as you hit the front. And shift up before or just as your backwards movement stops. If you do it right, you can keep your power changes pretty small, and avoid having to dramatically increase or decrease power. If you increase power too much when you’re in the back of the bunch, you’ll risk shooting out the front only to be reeled back (wasted effort). If you cut power too much when you’re at the front, you risk being shot out the back and needing to pour on the power to catch back up. So, paradoxically, you end up reducing power when you’re at the back, very slightly, and increasing power when you hit the front, very slightly :slight_smile:

I’m no racing mastermind, but this is a general way you can work on bunch placement.

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7

You’re getting a pretty big penalty for being tall. I don’t know if that explains everything you experienced, but it is a significant factor in Zwift physics.

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8

I’m similar to OP, 193cm and 90ish KG. The flats are never as easy as lighter riders seem to think they should be for me :smiley:

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9

sit last wheel. don’t space out and lose it though because… well, you’re last wheel. but the draft is best there

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10

I can never manage to do that well, which is why I do what I do above. I also need to be near the front for the start of climbs (the short climbs, the ones I stand a chance of sticking with the lead group on), and at the end of the race so I can choose the move to follow. It’s probably more effort to drift around like I do, but it minimizes my chances of spacing out and paying for it :smiley: Last race I did, I missed the move in the final km because I was at the back of the group at the wrong point. User error totally, but hey–play the cards you know how to play, right?

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11

yeah, knowing when to move around people probably takes some intuition or practise. a simple way to avoid problems is to move up on climbs and let yourself slowly drift back. i like to sit at the back because i can see everyone in front of me and they can’t see me

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12

Probably easier than me having to do non stop 4.5w+ sprints to stay with the super fast Yumi group on Volcano circuit. :wink:

Someone else I ride with is 49kg and she has an even worse time.

I suspect the OP needs to confirm he isn’t on TT bike. I made that mistake by accident and wondered why I was doing 5.0w+ while everyone else was cruising along at easily 2.8w. I quit, changed the bike and rejoined.

The trick with the groups is to always never let off the power totally and never get on the front of the group for any reason at all, go near the front but never get on the front.

No, I’m not getting fitter by much, just better at bludging wheels! :wink: With great difficulty I can stay with Constance group for 35km - but the volcano climb wrecks me.

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13

It also helps to accelerate into climbs. Don’t be slacking right as the climb starts, and also don’t be near the front in the approach. ~100m before the climb begins, accelerate from the back of the group toward the front, using the draft to increase speed.

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14

I’ve already gotten more useful information from this thread myself than from the Andre Greipel Sprint School I signed up for :smiley:

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15

I don’t use the TT. I have been using tron, but am experimenting with other frames and wheels.

16

Have a look at zwifterbikes.web.app to easily analyze the Zwift Insider data for a given route and your level. It won’t help you understand different surfaces such as gravel, but on pavement it will give you a good idea of what’s fastest across the entire route. You may want to pick the lighter options on routes where you worry about getting dropped on climbs, though it won’t make a huge difference. The Tron bike is fastest on many routes that don’t have lengthy climbs.

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17

From your Zwift profile alone it looks like you’re a high C rider, the FTP you have from TR would make you a lowish B. To master the draft in Zwift is difficult if you’re on the limits, which it sounds like you would be in a short B race. I’d give the C races a crack until you’ve mastered this skill. As others have indicated, it’s a matter of sitting at the back until certain pinch points. Before a descent, tuck into the pack and /or be moving forward at the crest. On climbs or if there’s a chase on try to be in the front third of the pack, but always behind someone.

In this video I do a pretty decent example of how to maximise it, though it’s slightly different due to the stupid Burrito powerups being in play

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18

John

I wanted to say exactly the same as Rob but didn’t know how to put it tactfully.
At the bottom of B cat Everyone is just hanging on for dear life with no chance to put any of the great draft ideas above into play.
At the top of C cat there is the chance to move around the pack to get the best draft, physically you are able to put race plans into play.

If I may mention your specific power numbers.

You mention your TrainerRoad FTP of 329w which would make you a B cat on Zwift but as far as I can see your best 20 min power on Zwift is 299.

299w roughly converts to an FTP of 285 which is also the power you averaged for 30 minutes in your best race. At your weight this equates to just under 3.2w/kg so as you can see on ZwiftPower you are a Cat C.

However Category Enforcement (CE) uses a different method to work out your category and also uses all Zwift rides not just those that go to ZwiftPower.

I’m not sure what your zFTP & zMAP figures are, they are on your Zwift.com profile page.

What I can tell you is that your 2 min, 3 min and 5min power numbers (on ZwiftPower) are too low relative to your 20min 299w figure. The way CE works this will most likely increase your FTP figure and put you in CE cat B.

I would recommend you have a good warm up and then really knock out the best 3 minute effort you can. Seems ridiculous to say it but that effort might put you back in C cat which is probably where you should be racing until you can get your FTP on Zwift back nearer to your TrainerRoad 329w.

You may decide to remain a CE cat B and push yourself at a higher level. I’m no coach but your power numbers suggest to me that your 5 min power max is too low to hang with the B Cat on short fast races. A few good workouts concentrating on 5 minute intervals like the link below will both improve your 5 min power and also confirm whether your Zwift FTP is set correctly.

To play with the benefits of draft you first have to be able to sit comfortably within the pack.

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19

If they are low compare to his C assessed 20 min power I doubt CE would up him to B?

20

I think you might find a few people on this forum who have found increasing their 3 min power changes the position of the CE curve and actually brings zFTP down.

The Category Enforcement side of CE has been fantastic in my opinion. Races seem to be ‘fair’ without obvious riders racing well below their ability.

The category calculation side of CE appears to be ‘iffy’ and has caused most of the CE comments we see on this forum.

I was greatly in favour of using short term power numbers to arrive at a more sensible 20 min power number for those racers cutting their power deliberately at 18-19 minutes. I just don’t think it is working quite as well as anticipated (for all riders).

EDIT - I think he is CE B cat as that is what he is racing but of course I don’t know his non ZwiftPower efforts. He may of course be choosing to race up a category !!

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