Why would you want to change the physics to avoid cheating. Why have physics in the first place.
i don’t see the point of it either… cda and height aren’t strictly related and unlike in real life there’s nothing you can do in zwift to alter it. if the air in zwift is entirely static then i don’t see why everyone’s cda shouldn’t be identical either
ok, but the point is that if you’re 180cm there’s nothing you can do to make your cda better than a person who is 165cm on zwift, when IRL that person can absolutely have a better cda by working on their mobility, making positional adjustments and so on.
apologies but at 165cm and 55kg i am very firm in my belief that exceptionally light people have plenty of leeway in zwift racing as it is thanks to the scuffed category limits. i sympathise with guys who happen to be 180cm tall if they’re really taking a frankly insane 15w penalty over me that they have no control over. if consider that difference in reverse then adding 15w onto my FTP would add up to probably an entire .5wkg on my 20min
I am 183cm and I don’t think it is a penalty. It is just Life. It is the same as IRL I have to get super low to cut thru the wind but the smaller guys can also get low, they even have smaller bikes so they can really hide. IRL small guys can hide in my draft with less power.
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When I go riding (IRL) with my 52kg 165cm wife this is very obvious. I hardly notice when she’s in front of me, I look straight over the top of her 
I don’t think it is really controversial that zwift tries to estimate cross-sectional area using height and weight. What else could they do? Assigning everyone the same CdA would give a huge benefit to larger (heavier, taller) riders. I’m not a great cyclist but my long legs and 80+kg of mass provides vastly more power than my wife is ever going to manage.
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Doing some very quick math based on Training and Racing With a Power Meter Journal: Estimation of CdA from anthropometric data and Cycling Physics Calculator, the height difference works out to 1–1.5 W/cm at 40 km/h 
@S_A_ccc there’s nothing the taller person can do to be more aero that the shorter couldn’t. It’s not 1:1 because drag is quadratic and bike size isn’t linear, but on the other hand there’s also a floor to how low you can get.
If you’re losing a group on descents, it’s not the height that gets you.
And if you’re worried about cheaters then worry about the cheaters.
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Does Zwift go so far as to calculate draft differences based on the sizes of individual(s) in front or behind each other? That is, providing less benefit for a larger rider behind a smaller rider than it provides if the front rider was also larger?
Blockquote You ABSOLUTELY DID say that ^^^!
You’re incorrect and took the wrong quote.
I was responding to where you stated: “So just punish small people instead…”. And the quote you did use was taken (slightly) out of context - I was proposing to ‘adjust’ height calc’s not eliminate them.
And also, in regards to punishing people, the game, as-is DOES punish smaller people, smaller slimmer people that is. For example, an ex-swimmer with really broad shoulders would have more drag. I mean I’m splitting hairs now… but my route argument is very valid: Height isn’t the ONLY factor in determining a riders drag coefficient.
After some thought I realize that it would be VERY hard to adjust the game because it would screw up everyone’s records/personal bests, etc… None the less I think my points were very valid: Riding position (as well as other factors) have a relatively greater affect on drag than height alone, and height/weight greatly plays into the hands of people who decide to cheat - less than 1% of Zwifters ACTUALLY weight under 50kg and have an FTP of 300+. Probably more like 0.1%.
The solution is probably better dealt with via category enforcement opposed to modifying the game physics.
There is a whole thread on this.
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