Zwift Chat

[<Tommy>]

According to the articles in Feltet. dk, draft in Zwift is only half of that in the real world.

Im interested in the science behind their conclusion. What protocol did they use Lars? Maybe if you link it I could see how I get on with google translate.

 

[<Tommy>]

My main ‘issue’ with zwift accuracy is something they can’t do much about. It’s the lack of real world conditions.

No change in weather and perfect tarmac make it directly incomparable to my outside riding experience. Using a power meter bridges the gap but comparing speed averages is a non starter. In that regard zwift is very flattering. That’s partly why I’m highly skeptical about anyone claiming to recognise the precise level of difference between the two with any accuracy without science to back it up.

 

[bridgy]

Im interested in the science behind their conclusion. What protocol did they use Lars? Maybe if you link it I could see how I get on with google translate.

I think it's just that "standard" draft in Zwift is - and always has been - about half the effect of drafting measured IRL. Zwift then added Double Draft as an option for race organisers which some use and some don't - "double draft" or "full draft" in Zwift is meant to be closer to the real life draft effect.

 

[LBHIFI]

Im interested in the science behind their conclusion. What protocol did they use Lars? Maybe if you link it I could see how I get on with google translate.

No science, just a mention by Alex Rasmussen who is the Zwift ambassador in Denmark.

[edit]
Found the article: https://www.feltet.dk/nyheder/alex_rasmussens_bedste_zwift-tips/?test=2017

Google translate
"In a large field, however, there is certainly less draft in Zwift compared to in reality. In a huge field on the road, you only have to step 100 watts to run 45 kilometers per hour, but the power is halved in Zwift, so you can get a good workout out of it. After all, that's what it's all about in the end."

 

[Norry1]

I think it's just that "standard" draft in Zwift is - and always has been - about half the effect of drafting measured IRL. Zwift then added Double Draft as an option for race organisers which some use and some don't - "double draft" or "full draft" in Zwift is meant to be closer to the real life draft effect.

THIS ^^^^

 

[<Tommy>]

I think it's just that "standard" draft in Zwift is - and always has been - about half the effect of drafting measured IRL. Zwift then added Double Draft as an option for race organisers which some use and some don't - "double draft" or "full draft" in Zwift is meant to be closer to the real life draft effect.

THIS ^^^^

Then that tells us what zwift set the draft level at relative to their calculation of the draft effect. But it would be nice to know how they came to that calculation. How it is effected dependent on the number of people in a group. And probably most relevant how accurate it is to reality. I wonder if anyone has tried to put it to a proper test.

 

[Randyberlin]

I 'd like to see the science behind the drag created by the dreadlocks. My baldness had given me some comfort thinking it's more aero.

 

[bobinski]

Actually if you look at Zwiftpower most races don't use double draft.

It's indicated on ZP by a picture of a van on the events list

👍
I didn’t know that. Where do you see it Paul? Just tried ZP page on my phone and also via companion app and cannot see where it would show.
edit
I kept scrolling and eventually found one. Learn something new every day😁

 

[bridgy]

Then that tells us what zwift set the draft level at relative to their calculation of the draft effect. But it would be nice to know how they came to that calculation. How it is effected dependent on the number of people in a group. And probably most relevant how accurate it is to reality. I wonder if anyone has tried to put it to a proper test.

I expect Zwift's actual algorithm will be as secret as the recipe for Coke so I doubt you'll find the answer you're looking for!

But there's lots of data that's been gathered on this sort of thing over the years - same with rolling resistance, wind resistance, the affect of weight etc etc - it's just physics and experimentation I suppose. But yes obviously any algorithm they settle on will have to take certain assumptions of course. And averaging out a whole bunch of measured data

 

[CXRAndy]

According to the articles in Feltet. dk, draft in Zwift is only half of that in the real world.

Nah Nah

I wish it was just a little more realistic. Ive been wafted along in packs in real life and pacing behind a solo rider. I go from Z2 to Z5 HR from drafting to leading a pack. That never even comes close in Zwift.

 

[bridgy]

Nah Nah

Yeah but that's got nothing to do with your claim that it disadvantages bigger riders more Andy 😉

 

[steverob]

Lars does that include rides that use double draft? I think most probably do now.

I think that not long after Double Draft was launched, most races did seem to be using it for a while. But then as people realised that with it switched on, it meant it was so much more difficult to launch a breakaway from the blob and even if you did manage to, nigh on impossible to make it stick (unless it was on a long climb), so it then started falling out of favour and now only a handful of races continue to use it.

 

[CXRAndy]

I think that not long after Double Draft was launched, most races did seem to be using it for a while. But then as people realised that with it switched on, it meant it was so much more difficult to launch a breakaway from the blob and even if you did manage to, nigh on impossible to make it stick (unless it was on a long climb), so it then started falling out of favour and now only a handful of races continue to use it.

That's what it is like in real life. Solo riders always find it difficult to break free. I would have thought that having more, closer together at the end would make for an exciting sprint finish

 

[<Tommy>]

I expect Zwift's actual algorithm will be as secret as the recipe for Coke so I doubt you'll find the answer you're looking for!

But there's lots of data that's been gathered on this sort of thing over the years - same with rolling resistance, wind resistance, the affect of weight etc etc - it's just physics and experimentation I suppose. But yes obviously any algorithm they settle on will have to take certain assumptions of course. And averaging out a whole bunch of measured data

What I’m most interested in in this debate isn't how zwift calculate draft to be fair. But the difference between zwift and reality.

 

[bobinski]

I think that not long after Double Draft was launched, most races did seem to be using it for a while. But then as people realised that with it switched on, it meant it was so much more difficult to launch a breakaway from the blob and even if you did manage to, nigh on impossible to make it stick (unless it was on a long climb), so it then started falling out of favour and now only a handful of races continue to use it.

so, peeps didn’t like it being a little closer to real life 😂
Come back bkool- everything is forgiven and forgotten