Same TDZ stage 1, same Watt, 5min difference result on 27km?


I’m using Zwift since a few months and was only riding single rides with no reference to group rides/races… However, with the TDZ stage 1, I found out that my colleague who did the same race and distance was significantly quicker with having the same Watt.

I red some Zwift articles about weight, drafting, stage type and bike. We do have a slight different weight, but finishing 5 min later with identical watt and only 27km is really guessing for me?

TDZ stage 1 Flat:
my result
Time:46:06 min
ave Watt: 216W
Distance 27km

Time: 41:16 min
ave watt: 215W
Distnace: 27.8

Thanks for helping!

Two things come to mind.

1 - We don’t know the weight difference between you and your colleague.
2 - He could have been in a much bigger group which would naturally go faster because of the draft benefit.

  1. I’m 8kg less than him
  2. I do understand the draft benefit, but I’m really surprised how much delta this brings on just 27 km. I mean I was also not on my own during the ride.

The draft is huge in TDZ. I averaged 44kph at 3.2w/kg (217w) in a big group.

Hard to know accurately without having been there.

Also, TdZ has Double Draft switched on. So the drafting effect is absolutely massive.


Also I believe that where you spent the watts over the course can have a lot of impact. eg. going above your average on uphills and less than your average on downhills will likely net a faster avg speed over the course than spending the average wattage on both uphills and downhills.

Probably a bad illustration, but whatevs. If you put out consistent 200 watts on a course that goes 10km up a 5% hill and then down again at -5%, it will take roughly an hour. OTOH, if you put out 300 watts on the uphill and then 100 watts on the downhill and still ‘average’ ~200 watts over the full 20km, you’d shave somewhere in the ballpark of 10+ minutes off your time.

on a flat road the heavier person putting out the same watts would go faster (I think)

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Do you and your friend use any other training platform where you could compare Normalized Power (Zwift doesn’t show this metric)? HIs might be much higher.

For the same absolute # of watts, on flat or uphills, the heavier person will go slower (all else equal like aero). I think you meant ‘putting out the same watts/kg’ – in which case the heavier person will be going faster (I think) on a flat.

No watt/kg I can understand.

Thx for all the feedback, it seems I underestimated all parameters in Zwift that influence the watt vs speed overall

Maybe bike choice?

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