Accessory weight

Hi, has anyone done the calculation to figure out what number Zwift uses for the weight of equipment that is not bike/wheels? I.e helmet, shoes, bike computer, water bottles or whatever. Is this number zero?

We don’t even know whether the bikes that are in game have alloy components or whichever groupset, so pretty sure there is just one arbitrary weight factor added onto the participant’s entered weight based on the bike frame model chosen – which fwiw also has a separate CdA factor assigned to it.

Seems you’re suggesting the accessory weight is zero but I am curious whether that’s true. Seems fairly easy to calculate, but not sure if I should waste my time doing it, or if it’s been done. Just need to ride up a steep hill at 200w with a rider weight of 150kg, and try again with a rider weight of 200kg. Plot these dots on a graph, connect with a straight line, check y intercept. Using the lightest bike and wheels in the game, which I assume come out to about 6kg, y intercept - 6kg would be the accessory weight.

Ok, but how do you run simulations wearing no socks or no water bottles (for the same bike frame), or how do you add a GPS computer in game and then measure by taking it away? How do you know that for the lightest bike in the game, that zwift is using 6kg before accessories?

I’m suggesting that they probably tack on the same margin onto every bike (eg. 1kg or something simple along those lines). I doubt they’d give you a weight penalty for wearing an earned new helmet or pair of sunglasses. Now you could also wonder if taller riders get larger frames and more bike weight?

It’s not like I can do anything with this information anyway. Obviously there’s not a choice to virtually leave water bottles in the bushes to tackle adz. But this is more entertaining to investigate than just joining coco for some laps. If the non rider weight number comes out to something like 6kg then we can conclude zwift is just not counting other equipment at all, whereas if aethos+lightweight wheels come out to 8kg then it more or less makes sense.

I have a sneaking suspicion that Zwift marks accessory weight to something unrealistically low and am looking forward to having another thing to complain about on these fora.

i doubt it has any weight ingame. it used to be the case - i think the process is a little different now since the wording of the rule has changed - that for a professional virtual race, the rules stipulated that a weigh in must be done in “full cycling kit”, and your weight had to match whatever the scales said for the event. i’d be dremelling the sh*t out of my cleats if that was still a rule. so from that alone i would guess the ingame kit itself carries no weight

if there are any premier league/zgp riders reading this thread now or in the future, sorry if that actually is still the rule and i just blew up someone’s hustle

Or for that matter smaller riders get smaller, lighter frames.

From what I can see there is no real difference visually between the frames (that would be difficult work for the 3D artists). But it would be interesting- 51cm frames are always a bit lighter than 58cm of the same frame.

I wonder if @Eric_Schlange_ZwftIn has done any tests to see if the new body types make any difference? Now that you can choose the giant beefcake avatar or a little skinny one, does it make any difference on CdA?

We know component CdA’s for the frames, wheels front/rear, along with weights of individual components as well; such as forks, frames, cranks, derailleurs, handlebars, etc. All of that is very much encoded.

And to answer your question Mike, highly unlikely; as it’s based on weight and height calculation; not visual (which is something Eric discussed in his posting about the height disadvantage; back when shorter people got the beefcake avatar)

Helmets and other cosmetics make no change (nor should they IMO).

Also looking at said weights, it’s a safe assumption that no, bidons are not part of the CdA and weight as “ballast.” (as not many bikes have the bidons anyway)

To add about frame weight, this was discussed on FRR about weight bias for categories.
The reality is, with modern frames (“modern”), the weight difference between an XL and a XS is rather insignificant; not enough for it to matter, but to answer that question, no there is no indication a shorter rider gets a lighter bike; as again, weights are encoded, see first sentence.

Also to answer a question that wasn’t asked…
wheel weight encoding appears to be determined by real-world object weight + tire weight.

I don’t think there should be a difference between in-game helmets, but the helmet, shoes, etc should weigh more than 0 grams, IMO. This opinion is subjective but it’s informed by real world experience. To a 200kg rider, the helmet weight is fairly negligible, but to a flyweight it’s less so.

The bidons are trickier to deal with bc obviously pros finish races without them, but also IRL we spend most of our lives with bottles in our bikes. So I’d just as soon they add 1KG as an allowance for water, maybe 3kg for all accessories in total.

Some of the ways Zwift could be made more realistic are impractical to implement with current technologies (e.g. using real world rider position to calculate CdA), but this one seems like a pretty low hanging fruit…

Personally I just fail to see why it matters or has any importance; the bikes that have bidons are usually far less aero in the first place.

It seems a bit silly to me personally to nerf the already less aero bikes even further because they have a fake bidon that your avatar sips from every time you enter Z1

Reality is, this isn’t low hanging fruit because it’s not a thing on all frames, and note even some bikes like the ConceptZ1 doesn’t even have a standing animation (that’s more important than all bikes having bidons)

Alas the point remains, a few hundred grams here and there genuinely makes no difference when we have no real life comparisons in the first place; so adding 156g on each person is meaningless if it’s something everyone has.
And then the people with fake weights or not updated weights will find out about this, and lower their weight to counteract it anyways because why not…

Meanwhile, most of us are thankful helmets don’t alter your area / CdA, because then everyone would put the aero helmet on and leave it; that’s … not fun, and it’s also ugly (ugly if everyone has it on).

If anything we want to push for more neutralized stuff; so we can have more customization without the risk of subjecting ourselves and trying to hit a “meta” like all multiplayer games suffer.

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do you think a 30kg child or a 100kg adult will have an easier time carrying a 50kg backpack up a hill?

now scale that down to a few kg for sundries, and the point stands.

Nobody suggested that different helmet choices should change your in-game speed. That windmill is purely a figment of your imagination.

If your point is that nothing matters because there is cheating in watopia, then why even log on?

I think it doesn’t matter because the standards don’t matter (because they’re neither written nor enforced)

People already lie about their weight; there is no written standard as to what your weight should include (should it be dry or wet weight?, shoes, no shoes? etc.)

Meanwhile you’re talking about <1kg worth of weight here.
That’s not going to matter…

It doesn’t matter because if it were an addition in-game, it would affect everyone equally; thus “everyone” would be “slowed down” by one whole kg, which for the record, means less than being able to steer the short way around turns if you were able to hold a perfect bot-steady pace on any route Zwift offers.

Therefore no, I really don’t think it matters; because nobody is carrying a backpack up a hill in Watopia.

And again, the reason why none of this matters, is because Zwift does not replicate real life physics; they’re altered.

The “this isn’t real life” cop-out that people always fall back on when discussing Zwift is really boring and obviously misguided. If it isn’t real life/physics, then why does it ask for my IRL height and weight? Why does it model CdA? etc. Zwift is obviously trying to simulate real life as much as possible.

Likewise, the attitude of “I won’t answer the question, but the answer to your question doesn’t matter” is again, quite insipid. Have you no intellectual curiosity? If you have nothing useful to add, it’s quite acceptable to just move on to the next thread.

I guess I shouldn’t be surprised that the zwifter who is trying to shut down this discussion weighs under 60kg. 1kg is well over 1% system weight for you, and in this “sport”, 1% is greater than many winning margins.

It’s hardly a cop-out, and it’s not a “fall back” it’s literally just the way it’s programmed.

If you don’t believe me, go sit at any w/kg or power on Zwift, and tell me you can go the exact same speed at the same gradient outdoors… I’ll wait for your reply.

Everyone else here is willing to agree here on this subject, which is why it isn’t a fall back point; it’s a statement of fact…

Zwift had to come up with a way to program physics; using some IRL standards… sure, why not test some theories? (That said we have no idea if things like area calculations have changed once since the public release of Zwift; [and for the record I don’t think anyone cares, because again it hardly matters if everyone ends up being X kph slower or faster… except remember, Zwift’s own motto is literally “fun is fast”]).

Zwift is not trying to simulate real life as much as possible… take a look around at the competitors who are if that’s your thing.
Zwift is a workout platform, and came up with a physics system that works for group riding to keep people of massive variances, together… which again, most everyone else on the forum here knows these people could never ride together outdoors comfortably…

Perhaps spend a little more time reading up on Zwift’s physics and how things function; as you seem to be confusing a workout / group ride software to something trying to replicate real life; which is, for the record, not stated anywhere by Zwift; perhaps by other competitors… but not here.

Also I’m not sure I follow what you mean by trying to shut down; I came in here with facts about the software and what is actually coded in the game…

Lastly, please spare us of your attitude because nobody else here has one but yourself.


nothing obvious about it. there’s no wind, barometric pressure, or (thank god) collision detection. the physics model is based on real life but realism is not the goal. gran turismo is based on real motorsport, but is not a simulation … the colloquial term for that in gaming is “simcade”

if you want a definitive answer to your question, DM a staff member who posts in the racing forum, they know how the game works. everyone else, myself included, just be guessing.

I’d say follow the money.

Bike companies have paid for their bikes to be in Zwift, right? So they’re invested in the performance of their bikes in Zwift. If I was Company X, and they put my bike in the game, and the art department rendered it with a bottle and bottle cage that made the bike slower, I’d be sending some emails :slight_smile: Dear Zwift, please remove the entirely extraneous hydration system from our bike in your game, as it makes our bike slower than the competitor’s bike that you rendered without a bottle and cage."

There would be no motivation for Zwift to do this. They aren’t shooting for 100% correlation with IRL–the bikes don’t even have pedals. And the fact that we can easily choose to ride without a helmet means that they aren’t going to bother factoring in helmet weight relative to rider size, etc.

IRL, different paint jobs will make bikes heavier or lighter, and I don’t think the color slider changes that at all :slight_smile:

I would be very surprised if Zwift had put any thought into the weight of cosmetic things like bottles, cages, lights, etc.

There is a reason I’m often going back to Fulgaz for rides now. The speeds in that are much more honest.

You don’t just get your default 39km/h average at coco group watts/kg. But actually I use it only for riding up the big climbs we don’t have in Zwift and won’t have (because most people don’t like hills).

Group speeds are a complicated topic, I do think the mega coco and yumi groups are too fast, but if we look at Constance group, for the power put out (riding Tempus fugit course) 43km/h average does seem reasonable. That is with a group of about 10-15 people.

It’s funny to me to this day that we have a whole slew of bikes, some with features and others without; and you look at the “meta” frames, and you end up with the Spec Aethos, the meta climbing bike… which is one of like 3 or 4 bikes in the entirety of Zwift that has a bidon and animation on it.

Which is the last thing you want on a climbing bike / an animation you want to see while trying to do an effort, go around a bend… and your avatar sits up and takes a sip from the bottle :rofl: “ez”

Personally the way I see it is; neutralize a huge majority of this stuff and then nobody has to worry about it.
Every bike is equal opportunity (within reason / purpose that is [ie aero bikes are a grouping, climbing bikes are a grouping, training wheels are a grouping, disc wheels are a grouping, etc.]), and in theory more could be onloaded without that question coming down the pipeline of “why is X bike faster than mine in your video game.”

At least then we’d see more bikes on Zwift…

You can’t tell me someone at ZHQ if they were to ever watch one of the actual livestream races, sits and thinks to themselves “yeah, that 5 year old gray Spec Venge SWorks sure looks great with literally everyone else on it…”

Can you imagine watching a tour race, and everyone was forced to wear the same color and all the bikes had to look visually the same?
Now imagine if that color they had to wear was white… :upside_down_face:

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i just use the tron. i dont want to see my guy doing a julian alaphilippe impression when i’m sat like the :moyai: emoji irl

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