Forget all of this.
Zwift is a business.
As that, they prefer people happy and paying for subscriptions.
Happiness comes when people go fast at climbs, and at the same time are the best allrounders and descenders.
They only have to be small and light, so then will fly in EVERY terrain, not only uphill as IRL, because in Zwift they will kill everybody at ITTs and even downhill because the “almost zero” CdA which will make them faster in descents with 55kg bodyweights… 
Sure in Zwift every kid around there with measures as 155cm tall and 47kg weight will detroy him… 
Almost every recreational rider can beat UCI World Tour pros in Zwift.
Ask them, the joke is that they never can have an option (by far) to win a race, NEVER.
Meny of them said never had a top 10 in Zwift.
So, you say almost every Zwift racer can even hold a UCI World tour in real life Gerrie?
Tell the pros, that they have to take in account that they are racing against the whole world of recreational riders than can actually destroy them also IRL…
I was trying to express it in a more convoluted way, but I tend to agree. Fun is fast!
Nothing will change at Zwift.
Take it as a videogame, fantasy only.
You can control the frustration thinking that when you finish 67th, the lighter and smaller people that beat you, have nothing to do IRL in a flat race, and that was only the “Zwift’s reality”. And being satisfied with that 67th.
Or you can do as everybody: Erase your Zwiftpower account and “re-born”.
Set up your measures at 155cm tall 47kg weight, start flying and taking fun with the “Matrix” wonderful cyclist life.
I was going to post this when the hidden weight/height change was going to happen but as that has been postponed I thought I’d post it here.
A few days ago I thought I’d test to see how much faster I could ride if I changed my height from my normal 180cm to the minimum you can set in Zwift, 91cm.
The course was the Fuego Flats Reverse segment, 7.1km of flat terrain. I recorded the time it took to ride southward (not the official segment, you could say it was the reverse of the Fuego Flats Reverse segment), had a brief rest to recover then rode back on the official segment recording that time separately. I did the southward and northward segments both at 180cm then changed my height to 91cm and repeated the course giving me a total of 4 times to compare.
The bike was the Canyon TT bike (to avoid drafting effects) with Zipp 858/Super 9 wheels. Rider weight 80kg and average of 240 watts (3.0w/kg) +/- 1 watt.
The results:
Southbound @ 180cm : 10min 58sec
Northbound @ 180cm : 11min 1sec
Southbound @ 91cm : 9min 11sec
Northbound @ 91cm: 9min 13sec
Around 117 seconds faster at 91cm. I guess the northbound course is ever so slightly uphill which explains the 2-3 seconds longer it took.
The conclusion:
My speed was around 20% faster with the shorter height. I noticed in the first set at 180cm that I was riding at around 39km/h. After starting the second set at 91cm I immediately noticed I was flying along at 47km/h. I was kind of embarrassed at how fast I was passing people.
A quick bit of work with one of the online speed calculators (Bicycle Speed (Velocity) And Power Calculator) shows that at 180cm in height I would need to ride at 400 watts to match the times I was able to set with a height of 91cm. Incidentally a quick check with that same calculator shows that adjusting my height would only have made me 1.6km/h faster and not 8km/h faster according to the formula used in that calculator.
To put this into perspective, riding at 240 watts and 80kg is C category w/kg. To match someone doing 240 watts and only 91cm I would need to do A+ category watts (400 watts at 80kg is 5w/kg).
Remember, this is just changing the height, weight is also a factor in CdA. Sure, it was an extreme example but I was trying to prove a point about how height doping would become a massive issue if Zwift hid rider height. Cheating by height doping would have had me doing A+ cat speeds while still appearing to be a lowly C cat rider doing 3w/kg.
I knew height doping would provide an advantage but I had no idea it would be so massive. I suppose it helps explain how the little humans are able to keep with everyone else.
The course makes a difference.
Knowing the flats favor raw power and nobody really likes climbing, Zwift has courses like Richmond, Insbruck ring and the original Watopia hilly to even things out.
Titians Grove is great but the dessert flats is too much flat on Sand and Sequoias.
I think a better route is Titians Grove plus Ocean blvd counter clockwise.
What @Tim_Camden_C? Are you saying that uphills act as IRL?
If you’re replying to me, I’m saying if Zwift would tweak the courses a bit and have more rolling hills and short climbs instead of long flats and long climbs, I think racing would be more even.
I thought we were discussing the Zwift algorithms. Not the gradient of the courses. The algorithms should not fit the courses. They should be natural.
To me it seems like they try to change the terreighn to the map.
Maybe without that extreme height, but adding low weight, you could have similar improvements.
Let’s say 160-165cm and 52-55kg as many of the A+ best riders in Zwift.
They destroy UCI World Tour pros in flat ITT courses even with 80-100W less, and are also at the same time as fast as 90kg riders on descents
Good test. It just substantiates the hypotheses that they are using a CdA estimation that is off with regards to the rider height (the extremes) (see. thread “Fix physics simulation on the flat”). The impact of rider’s weight on CdA in Zwift could also be off. It would be interesting to see the results from the test with minimum weight vs 80 kg.
I concur with a desire for Zwift to me more realistic. I come in at 105kg and am a slow dog on climbs but I regularly ride with friends and on flat roads I’m often the one pulling at the front. My wife and I ride regularly and IRL she can’t keep up with me on the flats and I can’t keep up with her on climbs but in the Zwift world she has the advantage at all times. It appears that there is little consideration for climbing vs flat roads in the Zwift algorithm used to calculate speed.
No one can 80kg for 91cm
Compared the frontal surface of a 180cm rider and kids 91cm rider 40kg.
“Normal” Men have 1.9m², on bike we take 0.38m² for normal position
Kids = 1.1m², same proportion on bike it’s 0.22m²
According a 0.95Cx
Frontal surface 0.38m²
sCX = 0.36
For hold 40 km/h on flat you need 380W
Now a kids with same power but 91cm
Surface frontal = 0.22m²
sCX =0.209
How many watts for 40km/h ? 255W
And with 380W what speed ? 47km/h
How are you calculating these CdA, out of curiosity?
These are only following estimates of median value
But i think i’m not far from the truth 
Pretty much what I noticed several years ago but still get attacked from a handful of ignorant trolls (whom I’ve hidden) for even daring to suggest it. No matter how much proof we provide, there’ll be those who still believe that absolute watts matter on flat roads more than w/kg or height. 
As I posted elsewhere, I can understand why Zwift would want to simplify their calculations so they wouldn’t need a dozen Crays to calculate real-world dynamics for every rider. However, it does lead to short/light/young riders having a massive advantage over the rest of us that simply does not exist IRL.
It is what it is but I wish some people would make the effort to understand the way Zwift works, rather than dismiss it because it doesn’t dove-tail with their precious beliefs.
I have a feeling that after all this autocat testing we will realize that the problem has never been how categories are determined, but how Zwift computes speed in game. I don’t see anyone talking about how someone with 180W (3 w/kg) can keep up just fine with 240W (3 w/kg) rider in a group. If w/kg plays a heavy role in calculating speed in game, what’s the point of determining categories based on anything other than w/kg? If your time in a course is a function of speed, which is a function of w/kg, isn’t your time in a course a function of your w/kg? Isn’t then, all this seemingly new categorization system, the same crap in a different dress? Glass half empty…
On the flat? I get obliterated.
A light rider sitting in the draft don’t have to put out a lot of watt to stay in the Draft.
I did a outdoor ride with a friend, we attacked the KOM (flattish road). He could not pass me but could hang on just fine doing a lot less watts and w/kg.
A post was merged into an existing topic: Autocategorization Test Events & FAQ