Forum search & shortcuts

Zwift does it under...
 

[Closed] Zwift does it under measure FTP?

Posts: 2795
Full Member
Topic starter
 
[#11164286]

Just wondering I know about the “weight doping” but there seems to be loads of people who can bang out 3,4 5w/kg no bother! Is that normal?


 
Posted : 28/04/2020 8:50 pm
Posts: 3008
Full Member
 

I reckon it overestimates mine. I just put in my true weight as I don't see the point in trying to cheat it as I'm trying to keep it as realistic as possible.


 
Posted : 28/04/2020 8:53 pm
Posts: 953
Full Member
 

The sandbagging is a bit much, did a C race so 2.5-3 wkg, winner was pushing out 5.9 wkg and the first 120 odd were over the upper limit, don't see the point.


 
Posted : 28/04/2020 9:12 pm
 beej
Posts: 4216
Full Member
 

I'm not sure I get the question in the title vs what you've put in the post.

FTP is measured on Zwift from the power recorded on a ride, or FTP/ramp test. It just calculates FTP from the power numbers. If the input power is wrong, it'll give a wrong result. I think they use the .95 of 20 min average power as their general calculation.

3,4,5 w/kg is power to weight at a point in time, not FTP. Are you asking if it over measures power to weight?


 
Posted : 28/04/2020 9:16 pm
Posts: 13594
Free Member
 

Everybody is 45kg on Zwift!


 
Posted : 28/04/2020 9:41 pm
Posts: 2795
Full Member
Topic starter
 

Yeah sorry not very clear! I think I was looking to give the benefit of the doubt that people’s quoted FTP, and or w/kg are higher in zwift than in the real world due to the programming as opposed to anything else.


 
Posted : 28/04/2020 9:42 pm
Posts: 0
Free Member
 

What makes you think 3 to 5 w/kg is wrong?


 
Posted : 28/04/2020 9:43 pm
Posts: 28712
Full Member
 

Just a lot of liars I think.

I've never seen so many 5w/kg racers outside of pro ranks but you get 4000 a day racing in D on Zwift lol.

Last C race I averaged 303w for the race and for smashed into pieces by riders averaging 5w/kg.


 
Posted : 28/04/2020 9:44 pm
Posts: 28712
Full Member
 

What makes you think 3 to 5 w/kg is wrong?

It's not wrong, for some riders, sometimes, but day in day out that many on Zwift? It's fishy


 
Posted : 28/04/2020 9:46 pm
Posts: 3323
Full Member
 

Zwift doesn’t measure power, it gets the measurements from whatever device you are using. There is a lot of info of accuracy of different devices on line if you care.

For weight, well of course some people are optimistic. For example I can say mines accurate because my scales are linked to zwift, but in reality I weigh myself in naked instead of wearing riding kit, so it’s going to be under.


 
Posted : 28/04/2020 9:54 pm
Posts: 0
Free Member
 

I have a Stages power meter on my zwift setup and one on my road bike and I find that my FTP from Zwift sets tough zones on the road.


 
Posted : 28/04/2020 10:19 pm
Posts: 0
Free Member
 

My tested FTP is about 25W lower on Zwift than it is outdoors, so I’m pushing lower w/kg on Zwift than I could in real life. But I figure I’d still get shelled out the back even if I had my outdoor numbers. Plenty of people doing it legit on Zwift, and Zwiftpower does a good job at sorting out the sandbaggers if you’re interested in seeing how you really stack up.


 
Posted : 28/04/2020 10:21 pm
Posts: 291
Full Member
 

There seems to be a lot like

This chancer

Who seem to just make up their power (and who no doubt weighs no more than 12kg too)


 
Posted : 28/04/2020 10:27 pm
Posts: 39735
Free Member
 

I'm no pro and 3-4w/kg isn't really a challenge.

Case in point just did over unders with the club on Alpe duzwift alternate corners doing 3w/kg easy efforts 4w/kg hard efforts

When I race for an hour it's 3.8w/k average with some extended efforts in the high 5s low 6s

Output correlates with my 4iiii on the TT bike when doing IRL racing.

And im carrying about 10kg extra. @85kg. Which my FTP works out at 3.8w/kg If you put my output in 75kg you'd be at 4.2. 68 kg is not unimaginable at my height. ....

Once you start getting beyond. 5.5 w/kg for an hour I'd start to get suspicious. There are alot of fit people out there and alot of gifted people. -i know a guy who can run a sub 19min 5k on spec and doesn't run at all for training


 
Posted : 28/04/2020 10:32 pm
 beej
Posts: 4216
Full Member
 

Generally the output of an FTP test would be lower indoors - some coaches recommending having indoor and outdoor zones. Indoor is harder (no micro rests) and hotter.

So basically, Zwift is full of liars.

Even me. My Zwift weight is 69kg, I'm 70 at the moment in reality!


 
Posted : 28/04/2020 11:04 pm
Posts: 6949
Full Member
 

Seems a bit bogus to me - not even talking about the jokers with fantasy set-ups, but guys on zpower with supposedly accurate data. FTP of 5+ W per Kg on an amateur rider is not the club strongman, that's a straight beast who could mix it in a national level race. Guess there's a lot of national-level guys on zwift!

Depends on your build / absolute power I suppose - really slight fellas can hit 4 W kg without being considered unusually strong riders, but a big lad pushing 400 W hour power but would be quite rare ISTM.


 
Posted : 28/04/2020 11:10 pm
 feed
Posts: 932
Full Member
 

But Zwift recalculates your ftp based on actual riding, I put mine as 256watts as this is what I got from a Sufferfest 4dp test and EXACTLY the same from a trainer road ftp test over a year ago. After 2 months on Zwift at a high usage rate including some cat C races (where I was finishing mid pack) it recalculated my ftp to................. 261 watts 🙁

People who should be cat B and want to stay Cat C would be overstating their weight to keep their ftp\kgs lower.

Prob frustrating if you're the competative type, I just race against me. Do enjoy doing Zwift races. Sure have a look at Cat D results. Bet you get some real bangers in there 🙂


 
Posted : 28/04/2020 11:14 pm
 J-R
Posts: 1179
Free Member
 

In Zwift, as in life, no matter how good you are there is always someone better.

So in reality the only person you are racing is yourself - are you riding as hard as you can? If some people want to drop their weight to hit silly W/kg figures, they are only fooling themselves.


 
Posted : 28/04/2020 11:18 pm
Posts: 39735
Free Member
 

But Zwift recalculates your ftp based on actual riding, I put mine as 256watts as this is what I got from a Sufferfest 4dp test and EXACTLY the same from a trainer road ftp test over a year ago. After 2 months on Zwift at a high usage rate including some cat C races (where I was finishing mid pack) it recalculated my ftp to…………….. 261 watts 🙁

That barely even registers as more than measurement drift after all you can change your chain lube and win 5w

but equally you'll push harder racing than testing. That's a highly studied phenomenon


 
Posted : 28/04/2020 11:19 pm
 feed
Posts: 932
Full Member
 

but equally you’ll push harder racing than testing. That’s a highly studied phenomenon

That's very true, I peel myself off the bike after a race, and it's not like I'm threating the podium, just trying to pass a rider, not get dropped off the back of a group, not get passed by too many but realistically just not finish last.


 
Posted : 28/04/2020 11:34 pm
Posts: 2795
Full Member
Topic starter
 

Some good points here thank you! It’s a great training or entertainment tool at the moment been enjoying the training programmes! I think being able to see the W/Kg just got me thinking what was normal what was above that. Previously W/kg was just so thing I read about with relation to the pros the infamous 7w/kg for the tour etc. There just seemed to be a lot of people chucking out 4-5w/kg on a regular basis. It’s all a fun activity I’m only interested in getting fitter and hopefully will be able to ride further faster etc. I was just interested to see so many able to push what I assumed would be a high output.


 
Posted : 28/04/2020 11:34 pm
 feed
Posts: 932
Full Member
 

Now that I think about it, my ftp is 261watts and weight is 84kgs which puts me at 3.1 w/kg. I'd consider myself reasonably fit as in I can do a 5hr cycle but would be no racer. As stated I'm very much a mid pack finisher in Cat C on Zwift and would consider that to be correct for me given the Cat I race and where I finish in real world XC races (I've never done a real world road race of any description). And when I say "race" XC I use the term in it's loosest definition 🙂


 
Posted : 28/04/2020 11:40 pm
Posts: 39735
Free Member
 

Another thing to think about is. The trainer.

We had a local lad show up to our club organised Wednesday ride.

Handed us all our arzes by a long way .....averaged 7w/kg

Turned out he was running speed and cadence sensors on a turbo that wasn't on the list.....just picked a close one.

Even with legit trainers no two read the same ..... Wheel ontrainersxjust introduce a whole new level of inaccuracy and power curves a third level
That's before you start weight doping.

I'm reliably informed a tacx neo is worth a few watts


 
Posted : 28/04/2020 11:41 pm
 feed
Posts: 932
Full Member
 

I’m reliably informed a tacx neo is worth a few watts

Don't they also have a motor that kicks in on the downhills to enhance the real world experience?

The other thing I discovered (for myself) after my first race on Zwift when I did about 10kms solo is that drafting makes a big difference.


 
Posted : 28/04/2020 11:46 pm
Posts: 25943
Full Member
 

I was a mid-pack B on zwift last year and I'm a mid-pack crosser (V50 though, not open) in real-life. Might be a tiny bit better at something a bit more constant as I don't have much above "diesel".

err, what was the question again ?

I reckon if you're a genuine upper-half A on zwift you'd possibly be a pretty decent racer (depending on the mix of your skillz - certainly isn't all about FTP unless maybe you're a 25 mile TTer)


 
Posted : 28/04/2020 11:54 pm
Posts: 4892
Free Member
 

Go watch Alex Dowsett on YouTube

He’s been Zwift racing and TT’inh during lockdown and he’s getting beat in every race.

His Mrs rips the Michael out him also while he’s doing it so it’s an interesting watch.

But good insight into what numbers a Pro can put out and the interesting thing is it not massive so it kinda shows the issue isn’t maybe Zwift but people lying to themselves.

If you’re running a wheel off decent turbo then the power is the power no-matter what you’re weight is.


 
Posted : 28/04/2020 11:55 pm
 Haze
Posts: 5445
Free Member
 

Weight synced to Zwift from Withings scales via TrainingPeaks every couple of days or so, I’m just under 63Kg at the moment so 250w for 4w/kg is easily attainable.

Everyone wants their numbers to look good so nibble off a bit of weight here and there and squeeze another step out on the ramp test and you’re soon 4.2


 
Posted : 29/04/2020 12:06 am
Posts: 0
Free Member
 

I’m reliably informed a tacx neo is worth a few watts

Your havin’ a laugh. Check out the Dc rainmaker or gp llama reviews. They’re supposedly the most accurate trainer you can buy and don’t require any calibration. I’d trust someone on a Neo more than any other trainer.

Are you sure your not confusing it with a Vortex?


 
Posted : 29/04/2020 12:23 am
Posts: 8332
Free Member
 

From the events I've done on zwift watts per kilo is kind of irrelevant, it's all about how many watts you can put out. I have an ftp of 4 watts per kilo (at 66kg) and I get absolutely smashed in zwift. Gave up the group rides as I'm ruined after 5 min, and in the tts I'm usually well down my group results, despite usually having one of the higher w/kg


 
Posted : 29/04/2020 12:53 am
Posts: 28712
Full Member
 

From the events I’ve done on zwift watts per kilo is kind of irrelevant, it’s all about how many watts you can put out.

NOt so much, it's really both... but within certain limitations. Watts are watts and high watts bring high speed... but only on flat courses. On hilly courses you can have the watts but the 70kg rider will stil blow out the 100kg rider usually.
But again, if you can't put out the watts, you won't be in the game anyway.

Overall it's quite frustrating at the moment and the reason i'm doing STW social rides not racing currently, i don't mind racing ANYONE who's a fair racer, but someone putting out 5w/kg in a C race, is just pathetic. Sadly in a Crit race at the moment, the top 15 on the road will all be high 4's in C..... if not more. It spoils it for racing as you try and go with the lead group, knowing you can hold a 'fair' lead group, but then find out the lead group are all enough to win As...


 
Posted : 29/04/2020 7:59 am
Posts: 39735
Free Member
 

Your havin’ a laugh. Check out the Dc rainmaker or gp llama reviews. They’re supposedly the most accurate trainer you can buy a

Spoil my fun why don't you the latest gen neos are reporting -2 to -5% out on dcrainmakers tests. Basically exasperating the issue the op is experiancing.

As for w/kg not coming into play. I assume you only ride flat. On the flat it's power power power. Up a hill it's w/kg

Dowsett got pumped in the TT because zwift doesn't account for the fact be was altitude nor does CDA - basically zwift proves IRL -position is a vast majority of time trialing.


 
Posted : 29/04/2020 8:05 am
Posts: 2434
Free Member
 

I don’t bother racing anymore. I’m a B, 69kgs and 271ftp. Was getting battered by most B before lockdown, but it felt reasonably fair. Flat courses I’d get dropped and hilly courses were very hard but I’d do ok and only get dropped later in the race.
Since lockdown the races I’ve done are crazy. Gave up racing B so did a C to see how I fared. 281 watts average and 4.1w\kg. I finished 15th.
I also did a D group ride, was meant to be a nice easy ride at 2-2.5w/kg, not a race, but I finished it in 43rd place at 3.7w/kg average. My 20 min average was 4.0w/kg and that’s just a D group ride. I wasn’t in the front group, tried to bridge across thinking they won’t be holding 4.5w/k for long but they did.


 
Posted : 29/04/2020 8:16 am
Posts: 39735
Free Member
 

Those feeling they are getting pumped by the flats try an alpe d'huez race.

I'm seeing alot of the low power coupled with low weights giving high w/kg. That metrics only good for climbing.

Fwiw I'm 320 @85 kg.

I have no top end. Comparing power curves on ZP after events is funny. You see all those that give it beans at start putting out waaaaaay too much power for their ability to try and hold on and get shelled out the back.

My power curve it's pretty flat. Even come the end sprint I have to wind up for the finish from about a 1km out have any chance of a decent finish and ditch those with a good sprint but who are in the limits of their endurance

Race your own race don't be trying to *stay* with the front pack.

If the race is anygood it'll be on zwift power anyway and they will be expunged.


 
Posted : 29/04/2020 8:43 am
Posts: 26891
Full Member
 

I gaveup on on Zwift after a few week, just to hectic and people flying around at twice my pace. Switched to Road Gran Tours. Did Stelvio yesterday didnt see a soul apart from a couple of bots!! I have noticed on a group ride with a few people that are much quicker than me on the road I was able to mix it with them quite well. My knackered hips mean I have a very unaero position in the real world but it doesnt hinder me online. Anyway I can smack out 8w/kg (for about 10s). RGT doesnt estimate ftp like Zwift so not done a test imagine its about 3-3.5


 
Posted : 29/04/2020 9:01 am
Posts: 8103
Free Member
 

I’m reliably informed a tacx neo is worth a few watts

The Neo has historically *underread* very slightly, but outside of an independent dual-sided power meter is about as accurate as you're going to get.

Using the road feel (motor etc) actually makes it harder to hold onto the pack downhill because you have to get it in top gear and pedal like crazy, whereas a normal trainer will just take any power input and increase your speed. On top of that, road feel robs power over cobbles and gravel sections.


 
Posted : 29/04/2020 10:34 am
Posts: 4892
Free Member
 

At the end of the day it’s a game, take it a face value which is it’s a great way to distract from the fact you’re on a turbo which let’s face it, a turbo is dull as flip.

What I’ve rediscovered with Zwift is I can lose an hour on the turbo, work hard and enjoy it 😳😳

For me just that is brilliant. I’m not an athlete, I’m a 44 year old fat git and so is my avatar.

My avatar does now have grey dreads. (I don’t 😀)

I have an Elite Direto, i keep it calibrated in the app and it’s supposed to be +\- 2% accurate but I’ve nothing else to compare against. I’ve seen a few posts where people track a Direto against other PMs such as cranks and pedals and it seems to be similar.

Before the Direto I had a tyre driven wheel on Tacx and it was far from accurate and when o switched to the Direto I lost about 100watts overnight.


 
Posted : 29/04/2020 10:53 am
Posts: 39735
Free Member
 

The Neo has historically *underread* very slightly,

that was the joke.

+1 what tiger said. we did a 3 hour 100km club ride on sunday , We have a whats app group running along side and one of the lads sorts out a spotify play list and we have a good old time since we cannot get out on our group rides on a sunday morning.


 
Posted : 29/04/2020 11:16 am
Posts: 2048
Free Member
 

I tend to only do the big 'official' zwift races, like the Tour of Watopia etc. Which appear to be slightly more casual, until you get spanked from the start. Thankfully I use it as a tool to push myself, rather than getting disappointed with only finishing in the top half.

Although since signing up to Zwift power, I can see that I am clearly too 'strong' for Cat D races, despite only cracking the top ten once or twice. So any future events I will enter Cat C and enjoy coming in the bottom 10.

I can only assume those that do cheat get some sort of thrill from top, despite it being fraudulent?!


 
Posted : 29/04/2020 11:23 am
Posts: 5171
Free Member
 

Zwift are in the process of introducing anti-sandbagging rules which are being beta tested in some selected races. Although quite why people want to enter races they are clearly too strong for beats the hell out of me.


 
Posted : 29/04/2020 11:28 am
Posts: 11472
Full Member
 

Go watch Alex Dowsett on YouTube

He’s been Zwift racing and TT’inh during lockdown and he’s getting beat in every race.

I was going to mention Dowsett. It's kind of hilarious. To be fair he is at altitude which puts him at quite a significant disadvantage to start with, but he's getting some serious virtual kickings.

More generally, there are plenty of very strong riders in the world, and right now pretty much all of them are going to be on Zwift, but as above, it's the guys putting out a steady 6 w/kg who aren't pros that I'd be more suspicious of than folk riding at 4 w/kw.


 
Posted : 29/04/2020 11:36 am
Posts: 41874
Free Member
 

Also possibly an element of confirmation bias?

You're looking at the 6W/kg numbers, which people are maintaining for a minute at the front, then dropping back, and someone else pulls up so the leaders in the group always seem to be doing 6W/kg. Whilst you're hanging on at the pack doing a consistent 4W/kg.

Doesn't Zwift DQ you if your FTP exceeds the class? So it's basically geared towards sprinters as anyone capable of a so breakaway will be forced to race against people with a similar FTP, who can then sprint to the line.

My trainer estimates my FTP at 325W (I wish!), Strava's equally inaccurate but less optimistic average power on a 2h road ride is ~190W, with ~220-230W being a reasonably consistent number on longer segments up hills (i.e. where you'd expect it's guesstimate to be most accurate).

Don't take it seriously. At best it's a game! Go ride a sportive if you want to do some pretend racing after a lockdown 🤣


 
Posted : 29/04/2020 12:02 pm
Posts: 0
Free Member
 

Quite an enlightening thread - I’ve been getting quite depressed with how poor my ftp is on zwift - using a cheap tacx thing on virtual power (Bluematic I think it is on a resistance level 3 as zwift recommends). Even if I wreck myself I can’t get past an ftp of about 160. Now thinking I might just need a new trainer 😀


 
Posted : 29/04/2020 12:12 pm
Posts: 39735
Free Member
 

do you use zwift tinas ?

no zwift doesnt DQ you - ZP does if the race org has enabled it .

when yu look at end results you often see people who hold 6 w/kg ave.

More OFTEN than not i notice they dont have a lightening strike next to their name meaning they are on estimated power from sensors and an estimated curve rather than actual power.

seems somewhat pointless to me.


 
Posted : 29/04/2020 12:20 pm
Posts: 953
Full Member
 

As I said earlier C category race 2.5-3wkg, winner was over 5wkg for the full hour. I'm not that fussed as never going to be troubling the top spots but when you're pushing out pretty much double the acceptable figure I don't understand what the attraction is.


 
Posted : 29/04/2020 12:28 pm
Posts: 0
Free Member
 

Not sure if many of you have seen this chart from Trainer Road, showing the distribution of w/kg of their users.

null


 
Posted : 29/04/2020 12:36 pm
Page 1 / 2