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W/Kg units, why this metric?

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W/Kg units, why this metric?

Old 01-25-21, 12:14 PM
  #26  
La Tortue
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Originally Posted by himespau View Post
Because of the 95% thing, you'd be consistently in the 3.3 range and not really at risk of moving up.
I'm confused, if he thinks a FTP test will bump him to 3.3 then he should be performing at this level now. This means his latest three races should be close right now and this is what is used for his category rating. His FTP test will have no bearing on his ZP category. I can go into zwift power right now and manually move my FTP to 600 but it will not change my category rating. ZP category goes by performance in races. (I think it might have recently included events but not sure)
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Old 01-25-21, 01:14 PM
  #27  
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In my riding on Zwift I have learned that many of those riding the roads are ghost riders. Meaning they are people that where on the ride at some time in the past. They are not actually riding at the same moment of time.
Once I understood that and realized many people ride on whatever equipment they piece together to get on the platform. I just ride the best that I can for my self.
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Old 01-25-21, 01:27 PM
  #28  
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Originally Posted by Ed Wiser View Post
In my riding on Zwift I have learned that many of those riding the roads are ghost riders. Meaning they are people that where on the ride at some time in the past. They are not actually riding at the same moment of time.
Once I understood that and realized many people ride on whatever equipment they piece together to get on the platform. I just ride the best that I can for my self.
What? Source please.
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Old 01-25-21, 01:35 PM
  #29  
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Originally Posted by spelger View Post
I am not fully clear regarding this metric used. i don't race but i do see the race categories in zwift and they are separated by a W/Kg range. i get that it is power divided by weight but it seems a bit abstract to me...
What metric would you propose?

It is physics based. Think of the equations of motion, particularly going uphill and then descending. There's your answer. Since the bikes are physically captured inside of trainers, the handling and technical differences between riders are negated. This is power/weight is all that remains, beside the psychological elements of tactics and pain threshold.

Originally Posted by spelger View Post
while riding zwift (and i know it is imaginary and rife with cheaters) i occasionally see someone blow past me with a much lower W/Kg that myself, it is puzzling at times.
I think that you answered your own question right there...
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Old 01-25-21, 01:58 PM
  #30  
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Originally Posted by Phil_gretz View Post
What metric would you propose?

It is physics based. Think of the equations of motion, particularly going uphill and then descending. There's your answer. Since the bikes are physically captured inside of trainers, the handling and technical differences between riders are negated. This is power/weight is all that remains, beside the psychological elements of tactics and pain threshold.
..
I don't think the discussion is whether watts/kg can be used to describe how one individually does in Zwift; the conversation is more about why it's used to categorize riders for events. A 100kg rider doing 4 watts/kg will be putting out 400 watts, right? A 50kg rider also doing the 4 watts/kg will be putting out 200 watts. On flats, the 50kg rider, says a simple calculator I have, will be doing approx. 20mph. The 100kg rider will be going about 25mph. Yes, it will equalize on the hills somewhat, but unless the event itself is only upward, then whatever Zwift category is built for the 4 watt/kg folks will likely have inequities.
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Old 01-25-21, 02:00 PM
  #31  
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Originally Posted by Phil_gretz View Post
What metric would you propose?

It is physics based. Think of the equations of motion, particularly going uphill and then descending. There's your answer. Since the bikes are physically captured inside of trainers, the handling and technical differences between riders are negated. This is power/weight is all that remains, beside the psychological elements of tactics and pain threshold...
watts per CdA is king over most reasonably quick speeds.

I propose a more aggressive calculation of rider size and CdA. Ain't no way 220lb boys getting THAT aero on a road bike in real life to hammer around at 25mph at those powers. Just take a group picture of a typical A-group hammer ride, local crit top 10, local time trial top 5.................it will not look like the people powering around the flatter parts of Zwift worlds.
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Old 01-25-21, 02:10 PM
  #32  
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Originally Posted by burnthesheep View Post
watts per CdA is king over most reasonably quick speeds.

I propose a more aggressive calculation of rider size and CdA. Ain't no way 220lb boys getting THAT aero on a road bike in real life to hammer around at 25mph at those powers. Just take a group picture of a typical A-group hammer ride, local crit top 10, local time trial top 5.................it will not look like the people powering around the flatter parts of Zwift worlds.
I think you make an excellent point except I would say take the speeds used around Zwifts flattest Tempus Fuget and compare big boys data to one of the many Bike calculation apps that are available. Don't guess like you are doing. I believe you will find the numbers very ballpark similar. Zwiftf formula isn't made up. They are using H/w/cda etc. My speeds are pretty ball park.
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Old 01-25-21, 02:29 PM
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Originally Posted by Phil_gretz View Post
What metric would you propose?

It is physics based. Think of the equations of motion, particularly going uphill and then descending. There's your answer. Since the bikes are physically captured inside of trainers, the handling and technical differences between riders are negated. This is power/weight is all that remains, beside the psychological elements of tactics and pain threshold.



I think that you answered your own question right there...
no, i don't think so, i did not answer my own question. i understand that zwift is the land of make believe but i only used that as an example due to my limited knowledge of the units in question. I've seen that big chart (where my cat 6 or 7 self sits comfortably at the bottom):

https://www.cyclinganalytics.com/blo...he-power-curve

so i assumed that this is a prevalent metric used for...something like racing. that is what the original question was about. this thread sort of diverged to a "why does zwift use that metric for categories" thread. it is not the intent of the question that i was asking but due to my limited experience with racing (i did mention that i don;t race) zwift was all i had to compare between me and other riders. i don't mind the divergance because it is still quite educating.

and i don't have a better metric to use...thinking out loud perhaps zwift should auto categorize a rider based on past performance. yet, as another poster mentioned today's cheaters may drop their subscriptions if they could not continue to cheat. but then go where i wonder...?
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Old 01-25-21, 02:37 PM
  #34  
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Originally Posted by La Tortue View Post
I think you make an excellent point except I would say take the speeds used around Zwifts flattest Tempus Fuget and compare big boys data to one of the many Bike calculation apps that are available. Don't guess like you are doing. I believe you will find the numbers very ballpark similar. Zwiftf formula isn't made up. They are using H/w/cda etc. My speeds are pretty ball park.
This is pretty much the same response I see very often on Zwift forums about this topic, what you wrote there. That may be the case. I don't debate it, you might be right. Probably are.

I just don't see it reflecting real world results of people riding "flattish" land on their own in real life. My opinion. I see soooo many people rolling courses less flat than Tempus Fugit at over 20mph, over 21mph avg speed that NEVER even sniff that pace in real life. Out of 150 or so folks I follow on Strava, maybe 5 routinely crack 20mph avg pace on something with about 40ft per mile elevation.

Other issue on Zwift is the "semi infinite draft" on the road bike with sooooo many people on the courses. You can just pop from one group to the next and go crazy fast. So that has something to do with it. If you play the game of bouncing along those groups by upping the power in the gaps then recover while floating up through the group.......you can go pretty darn fast.
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Old 01-25-21, 02:56 PM
  #35  
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Originally Posted by spelger View Post
...thinking out loud perhaps zwift should auto categorize a rider based on past performance. yet, as another poster mentioned today's cheaters may drop their subscriptions if they could not continue to cheat. but then go where i wonder...?
They do this already, sign up for ZwiftPower.
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Old 01-25-21, 03:07 PM
  #36  
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Learn all the tricks Zwift has to offer. A TT bike doesn't allow you to draft. If you want to free ride with no riders unplug the app ride on your computer or set up a group ride with just you and you can ride any course any time solo. I think having a good grasp of Zwift will turn many of these issues into non-issues.
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Old 01-25-21, 03:09 PM
  #37  
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Originally Posted by unterhausen View Post
Maybe they should have watts based racing and avoid the possibility of scale doping.
Wouldn't that just advantage big guys?
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Old 01-25-21, 03:29 PM
  #38  
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Originally Posted by Sy Reene View Post
Right. So Zwift has your power output. But they also have, if you have any past history on the platform, how you performed using the power you had. I guess I'm wondering why Zwift just doesn't assign each person a category based on that?
Not sure what you mean by this. Your power is the thing they use to calculate your speed through the 'world', based on your submitted height and weight, and the equipment you've chosen. Your power IS your performance.

Zwift Power logs all your performance data in races and assigns you a category when you sign up.
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Old 01-25-21, 03:37 PM
  #39  
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Originally Posted by wgscott View Post
My biggest problem is in the denominator.
Yes, but that large denominator you have means that on downhills you'll blow past those with little denominators, since you overcome wind resistance better than they do. At least that's my plan.
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Old 01-25-21, 04:01 PM
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Originally Posted by burnthesheep View Post
I just don't see it reflecting real world results of people riding "flattish" land on their own in real life. My opinion. I see soooo many people rolling courses less flat than Tempus Fugit at over 20mph, over 21mph avg speed that NEVER even sniff that pace in real life.
I see this, too.
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Old 01-25-21, 04:24 PM
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Originally Posted by Riveting View Post
Yes, but that large denominator you have means that on downhills you'll blow past those with little denominators, since you overcome wind resistance better than they do. At least that's my plan.
Except I have an irrational (?) fear of going much over 35 mph downhill.
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Old 01-25-21, 04:29 PM
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rocketing the bicycle over 40 mph is my goal each time I ride a certain route.
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Old 01-25-21, 05:34 PM
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Originally Posted by wgscott View Post
Except I have an irrational (?) fear of going much over 35 mph downhill.
You're wearing a couple ounces of lycra, depending on two tiny contact patches to keep you from terminal roadrash. Seems rational to me.

Still, there's something to be said for the feeling of flying downhill at >40 mph. Usually I say something like "That stoplight at the bottom of the hill better turn green soon!"
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Old 01-25-21, 05:37 PM
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Originally Posted by Riveting View Post
Yes, but that large denominator you have means that on downhills you'll blow past those with little denominators, since you overcome wind resistance better than they do. At least that's my plan.
I accidentally discovered that the way to go downhill faster in Zwift is not extra weight, but rather less height.

(I accidentally reset my height from 6 feet to 3 feet, and bombed down the back side of the Epic KOM at speeds >67 mph. I'm curious what a 3 foot tall, 205 lb cyclist would look like IRL)
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Old 01-25-21, 05:59 PM
  #45  
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Originally Posted by La Tortue View Post
What? Source please.
watch the bikes go by screen and no screen
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Old 01-25-21, 06:09 PM
  #46  
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Originally Posted by spelger View Post
i'd agree with better categorization for races in zwift. i tried one once. i put myself into cat C because i was border line C/B. when i did the race i was dropped almost immediately, it was really quite ridiculous, not fun at all. have not tried it since. i also think the cats are too broad.
So you tried a Zwift race one time, got dropped, and are now making generalizations about problems with the platform? Hmmm...okay. You might consider that there is a learning curve to racing effectively in Zwift that is a little different than IRL (many people have done videos discussing things to expect, tactics, etc.) Just like racing in IRL, there are subtleties to being efficient and effective that come from experience.

The typical pattern for Zwift racing is an all-out sprint from the gun before setting down after a few minutes of complete suffering. If you go out of the gate easy, or even at a solid tempo pace, you probably won't ever see the front of the race again. Knowing this ahead of time will make a big difference.

If you don't enjoy that kind of insanity, try group rides or one of the pacer bots. They're good places to get familiar with the pack-riding skills of Zwift, which aren't quite the same as IRL.
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Old 01-25-21, 06:20 PM
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Originally Posted by Ed Wiser View Post
watch the bikes go by screen and no screen
Are you talking about the riders that have what looks like a TV screen in front of their bikes? Those are people doing structured workouts. It's an indicator to the rest of us that they aren't just free riding. The color of the screen also indicates the intensity of their current effort.
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Old 01-25-21, 06:26 PM
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Originally Posted by Eric F View Post
Are you talking about the riders that have what looks like a TV screen in front of their bikes? Those are people doing structured workouts. It's an indicator to the rest of us that they aren't just free riding. The color of the screen also indicates the intensity of their current effort.
I notice a lot of people look at it to see if it's a good choice of someone to latch onto. Free ride folks often will latch onto someone doing LONG z4 workout sets so they can cruise at a high speed on their wheel for a long while and not worry about surges.
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Old 01-25-21, 06:40 PM
  #49  
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Originally Posted by burnthesheep View Post
I notice a lot of people look at it to see if it's a good choice of someone to latch onto. Free ride folks often will latch onto someone doing LONG z4 workout sets so they can cruise at a high speed on their wheel for a long while and not worry about surges.
Especially on Fuego Flats, it's not uncommon for groups of people free-riding to build around someone doing a long steady effort structured workout. I know some people get ruffled by it. If I'm doing that kind of workout, it doesn't bother me at all to be someone's pace bot, if that's what they want to do.
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Old 01-25-21, 07:10 PM
  #50  
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Originally Posted by Eric F View Post
Especially on Fuego Flats, it's not uncommon for groups of people free-riding to build around someone doing a long steady effort structured workout. I know some people get ruffled by it. If I'm doing that kind of workout, it doesn't bother me at all to be someone's pace bot, if that's what they want to do.
Yeah, I hooked onto a pair of riders going down the other side of the Innsbruck climb yesterday. Made for a really fast descent, since they were putting out something like 2.5w/kg or more.
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