The RP can’t go at infinite pace since the riders in front can only break the wind they can’t pull the RP
They can’t pull the RP past a certain point, but they can pull the RP to the point that its wattage keeps it in their draft. I saw this happen in the Festive 500 group ride on Tempus. I started with the Maria group, some of us went off the front and somehow caught up with Coco near the beginning of the second lap. (BTW, was this old-school Skinny Coco in the Rapha rides? We weren’t going anywhere near as fast as new-school Thicc Coco - just slightly quicker than Maria.) Coco got absorbed into our blob and we held 160-170w, 39-40 kmh average for most of the lap. Toward the end of the lap, most of the riders in the group drove up the pace to 42-43 and Coco got dragged along with them. I held 160-170 (2.2-2.3 w/kg) and got dropped.
I stuck with Coco for the entire Rapha ride on Island Hopper even though most folks ditched her (making me think they should add the drops game to the pace partners in events like this to help keep a bigger blob together for the advertised pace, but I digress…). A team of riders from the C pen joined Coco later in the ride as well, then there was a bit of a bigger blob.
That said, my average power was 190W for the ride, and normally with Coco my average power is pretty similar, so it was consistent.
Edit: Hard to tell for sure of course because of power fluctuations on the hills, but at least the average was consistent.
Zwift Insider found that with a line of four riders, lead rider at 300W, draft savings were 17%, 25%, and 29% for the three following riders. In the study cited above for a similar configuration of four riders the savings simulated through CFD were found to be 41%, 50%, and 54%.
My “seat of the pants” estimate is that in Zwift the maximum draft benefit reduces your effort to about 70% of a rider in isolation, no matter how large the group or your position within it. No where near the 5% effort deep in a peloton as shown in this study.
That 5% is the percentage of wind speed that the rider at the back feel not the power savings, cda is only a small factor in calculating speed from power.
How do you know?
That Zwift insider article is specific to TTT therefore he used the pictures for 4 riders in a small group. The pictures that Eric (Zwift Insider) used is from the same article that I sighted.
The numbers are drag. The colors in the lower two charts show wind speed and pressure coefficient.
Because when riding with a fast moving blob, the difference in power between being on the front vs. being in the center of the peloton is not 95%.
As stated in your second Zwift Insider reference.
“The size and strength of the draft also increases the more riders you have. If there are just two riders, the Zwifter behind can get away with outputting around 25% less power than the first rider. If you have a bigger group, that saving can increase to about 35%.”
That’s 65% of the effort of an isolated rider, not 5% as shown in the Eindhoven University of Technology study.
“Fig. 22. Estimate of revolution-averaged drag of every cyclist in Peloton A as a percentage of the drag of an isolated cyclist riding at the same speed. Background of the
figures (b) and (c) are contours in a horizontal plane at 1m height of mean wind speed (m/s) and mean pressure coefficient, respectively.”
You are correct. I had to read a bit more. Thanks for correcting me.
The point that I wanted to make regardless of the numbers (your seat of the pants feeling seem good) is that the Zwift draft look like this. I should have used this picture, that would be a lot better than numbers.
The red area looks awfully wide especially towards the back, I wonder if some artistic licence has been taken there to make the visualization look more clean… I think there might already be a few riders in the picture who would see their own avatars in the non-drafting riding position.
It look like that is developer mode in Zwift. Have a look at the picture below taken in “draft viewing mode” (the developer-only mode with rainbow streaks):
All the same, I refuse to believe that someone in the bottom left corner of the picture would still have a massive draft as indicated. Sounds like you are assuming that Zwift code contains no bugs…
Are you saying that the other riders always appear in their drops (out of draft).
I’ll pay closer attention.
I’m sure I’ve seen other riders sitting up and dropping down.
This came up from a group ride.
I dropped back to help sweep and I was trying to position myself as a just bearly drafting stepping stone so once stragglers got in the draft, they could just move up to the next helper.
I too have seen others sitting up but I think it is simply power-related, same as if you were riding without others around you. In a blob, all the others are (practically) always in the drops.
The speed has dropped a bit since the Rapha 500 is done so maybe it’s just people going back to normal riding, though the pace groups are still having big numbers on any flat course (Tick Tock or Tempus) and less numbers if the course has any hills at all.
