I am a smaller rider (161 cm/54-55 kg), and I’m wondering if Zwift makes adjustments to bike weight based on frame size. For example, I just bought the Specialized Tarmac SL8 on Zwift, and according to the Specialized size chart, I’d be on a size 49. I have a very tall friend who rides a size 61 Tarmac in real life. Obviously a size 61 would be heavier than a size 49 (maybe a couple hundred grams). I feel like it wouldn’t be too hard for Zwift to make some calculation about which frame size would be most appropriate based on height, and then scale the bike weight accordingly. They already scale CdA based on height. I’m also happy that Zwift removed the hard 45 kg minimum weight, but in all fairness, I think they should still have a minimum weight, perhaps based on BMI, so that a tall man over 6’ can’t lie and say that he weighs the same as I do.
I don’t know for sure but I doubt that it does.
I’m not sure that it really matters since almost everyone’s weight on Zwift will be likely more than a few hundred grams out due to various factors - weight not being updated recently, rounding errors, etc.
The best power meter have ±1% accuracy. Couple (or triple 
) hundred grams don’t matter.
This is what really matters. I was once racing against a senior man, 140 cm and 30 kg.
No, there was a data dump a while back which showed the actual bike weights. No adjustment for bike size, but each component does have its own weight. The figures may have changed when they reassessed the bikes a year ago but there’s no sign of changes with bike size.
As Steve mentioned the difference is less than the rounding error on most people’s self-reported weight.
Regarding fairness, height makes a significant difference to and it’s not accounted for at all in any of the categories. That hypothetical tall man would get a big performance boost out of lying and saying they’re the same height as you, and doing so wouldn’t force them to race in the elite category.
For those who don’t use a Zwift Ride, are we allowed to deduct our real bike’s weight from that of the Ride and subtract from our in-game weight?
You’re allowed to do whatever you want, where “allowed” means Zwift will take no notice of it. You could take the square root of your bike’s weight and subtract that from your in-game weight and it would make just as much sense.
Emma,
Unfortunately, there’s lots of shenanigans’ going on in Zwift when it comes to users reporting their height and weight. I sort of laugh at how many people only change their weight and not both height and weight. Ran a race several months ago and while looking over the results noticed a number of people obviously under reporting their weight. Saw multiple people that supposedly had world class cyclist weight (65kg / 140lbs) while reporting a more normal male height of 180ish cm / 5’10” height, which is basically cloning Tadej. And when you look at their profile pictures, you can readily tell that they don’t weigh 65kg 
.
While you may be honest about your spec’s, don’t sweat the 100g difference between large and small bike frames, you’re racing against people who suddenly lost 20kg Fri night 
So, race the race for your own sense of accomplishment and hope that karma balances out the rest.
Absolutely right, that’s exactly why I don’t race on Zwift.
I personally don’t understand why Zwift would allow people to decrease their height on their profile. I definitely think we should allow increasing height because kids/teens also use Zwift.
A little real decrease does happen when you get older, I used to be 178cm and I’m now 177cm, the wrong side of 50 years old.
You do know that people can use whatever profile pic they want and that it says absolutly nothing.
Or do I have to change my weight and height to that of the Red Bird as shown in my profile pic ?
Hahaha that’s true. They could even put a picture of Tadej himself on their profile 
Right there with you Steve, wrong side of 50, spine is compacting a bit, posture is slacking a bit, was nearly 6ft, probably closer to 5’10” now 
Would be nice if they could add some sort of integration with a smart scale to help people record their correct weight
Well aware that people can use any picture they want, I don’t use a selfie for any of the boards I’m on.
In this particular case, the guy’s profile pic was from a random club race of a guy that was closer to 220 - 230 than 140lbs; so highly likely it was a picture of them (do any of you use pictures of your favorite racer from the local Sun club race as your avatar picture???).
Point being, it’s not hard to find people in the race results that don’t have realistic height / weight ratio’s. I understand why this may be happening, but I can still be sad that it is.
And Pete, if you’re going to troll with a false equivalency question, try to come up with something better.
Cheers
I wasnt trolling. I just pointed out that no conclusions can be made from looking at profie pictures.
Depending on which leg I put most of my weight on, I can be taller or shorter by a few cms. The results of a crash and my left leg healing back shorter than my other one. It’s quite noticeable as well and caused a lot of problems with bike fit (eventually solved).
You are right that massive changes in height are doubtful and should be blocked.
Same as if someone goes from 70kg weight to 800kg or 1000kg and then goes to reduce their weight miraculously by a huge amount again. That has happened before.