The calculated CdA of a rider in Zwift depends on the riders weight, height and equipment, which is all good. However, how the CdA is affected by the riders height is completely unrealistic and unfair. This issue has been discussed on a number of other threads here on the forums, aswell as zwiftinsider also posting a article about it. Here are some examples:
There is a youtube video called “Why riders Height Dope on Zwift | Tall vs Small”
This is a test where a 70kg rider holds 300W on a course 4 times with the only factor changing being the riders height. 155cm 170cm 185cm and 200cm. In short, the results are:
40:28 for 155cm
41:15 for 170cm
42:09 for 185cm
42:40 for 200cm
Comparing the 170cm guy with the 185cm guy there is a difference in speed of 2.3%, running the numbers in a bike speed calculator gives a difference in speed of 0.77% with hands in drops and 0.86% difference with hands in hoods.
The person writing this forum post comes to the same conclusion: how-should-zwift-calculate-rider-speed/547828/25
So, there is no doubt that taller riders are heavily punished in Zwift.
Zwiftpower wants to avoid displaying riders height and weight because this is personal information that should not have to be displayed publicly in order to participate in racing on zwift. This was postponed however because of the fact that it will be easier for riders to cheat and the racing community did not like that. To me it is strange that Zwift does not adress the core issue of why people are height doping in the first place, which is that people are frustrated that they are unfairly punished for being tall.
Zwift also wants to become a serious competative platform, with the goal of being a olympic sport. It will be alot harder to attract serious competative riders if there is no place for them as a top level racer on the platform, why would a strong big rider want to commit racing on zwift when smaller riders will be faster than him/her on the flats anyway (even if they are not IRL). One of the beautys of bike racing is that there is something that suits everyone, bigger riders with a strong engine can specialize as a TTer for example. High level racing on zwift is pretty much just small punchy riders.