Done both and went about 8 mins faster indoors, without having to focus on conditions I pushed a lot more power indoors(ANOTHER 20 WATTS) . I went looking at my zwift times to find a similar performance. Used 25 watts less and was still 30 seconds faster. 35 watts less and I was 25 seconds slower.
Rode it yesterday actually. (Sept 14). It was windy when I rode it. On some of the longer stretches I had a headwind which sucked. And not much help otherwise. I felt like it compared pretty good in terms of the pitch Finished in a time of 1:01:01
Very nice video, great approach to the experiment. To replicate the effort, and not have to trouble yourself with other factors, you can stick simply to wattage. By this, I mean you can take the file from your Garmin/Strava, break it down to only have the section for the climb itself (so you would need only to know when you had start/stop signs on the FIT file). Then you can upload it to Zwift as a Custom workout, approach the bottom of Alpe d'Zwift and start the workout there. At most you would lose like a second, in terms of wattage synchronization, and saves the hastle of all the other calculations. I did it a long time ago with Ventoux, it worked pretty well (apart from the fact that I broke down in tears inside, because I forgot to turn on the fans and it got REAL hot, REAL fast haha). Take care and ride on!
I've always wondered about the climbing comparison to Zwift and outdoors! As someone who lives nowhere near any sort of mountains, it's nice to know that Zwift translates well. This was such a a great idea for a video! Seriously impressive work, Adam! Also, love the pup making a cameo 😂
Great video. Love the graphs and great to see that the time difference is so little! Also you have chosen a perfect day for this comparison ride. When I did the alpe it was the heat that got me, it was like cycling in a oven. :D
Great comparison - for those of us that don't have the real thing in easy reach, it's great to know that AdZ is a decent enough emulation in terms of effort to be able to do it and still feel some sort of achievement.
Bravo to you! Great job comparing, and I always wondered when doing this on Zwift. You are lucky to do the real climb! Thank you for all the hard work!
Well done! Of course when I got the chance to ride the real Alpe, I had a difficult time pacing because I was so excited to be riding the actual legendary climb. Doing it in the basement isn’t quite the same.
Amazing work and very interesting ! This is always a question I asked myself regarding the representativeness of an effort on a virtual platform (Zwift or rouvy for instance) ! Thanks a lot !! 🚲🙏
Never ask chatGPT to do calculations :). The problem is that 7.3 kph refers to speed at a 10 meter height. At ground level there's ground sheer, and wind speeds are much less. Also as you point out the wind comes from different directions. So you should average the effect of cross-wind, headwind, and tailwind, with appropriate weighting factors. The end result is that that amount of wind has only a small effect.
@@djconnel Like I said - I know it's not an absolute test of the accuracy (I don't even have a way to verify the validity of the wind data). My aim was to assess if AdZ is reasonably close. There are just too many variables to do a scientific test.
Managed a 1hr15m on the climb (on borrowed road bike) after a morning of Mega Practice back in July, Zwift on a Wahoo Kicker Move + Climb and I’m around 1hr25m WFH + Zwift really help me train, but the real world always give me that extra push
GCN did the same, I believe on Zwift with 2 different riders. Zwift they were on average 5 minutes quicker but they did mention on calibration on Zwift correctly.
You get a very good feel for the gradient, means you know you can do it. The rest is not comparable IMHO. Done it 43 times on zwift, twice in real life. Real life is best!
@@RoadtoA you're correct, you really can't compare indoors with outdoors, basic/rough is all you can fo, too many variables outside, more than you did well to compensate for.
Great video. But I have a question. What was your "trainer difficulty?" Default 50% or did you set it to 100%? I haven't climbed anything really big on Zwift since I did the Alpe a couple years ago, so I don't know if they've made any changes. But when I first started with Zwift I set it to 100%, thinking that would give me the most realistic experience. What I found was that climbing seemed much harder at the same gradient than it did in the real world. I then set it to 50%. To me that seemed much closer. So what was your setting?
@@Enigma71559 Trainer difficulty is irrelevant, lower TD only makes the climb feel easier but you still need to produce the same watts to go up. But for what it's worth, I use 100% trainer difficulty because in my opinion that gives me the closest feeling to the real thing.
Nice video and it was interesting, however, I think there is a fatal flaw in your argument. I believe that you asked the wrong question of ChatGPT. I think that the answer it gave to your question was the power lost to all air resistance. Zwift calculates the power lost to air resistance as we know when we try to cycle fast. What you wanted to know was only the power lost that was directly attributable to the 7.8kn wind: which as you correctly state, is not included in Zwift's algorithms. Furthermore, your ChatGPT answer says that it assumes the worst case i.e. it has made its caculation on a constant headwind of 18.3km/hr which is completely wrong. I'm sure that the wind would have an affect on your time but it would be much less than the 10% you state. Wind direction would also be a very important factor. I do agree however, that the road surface would be important, perhaps more than you have accounted for.
Oof, there's a lot to unpack here. I think your argument is fundamentally right, it makes sense to me. That said, it was not meant to be a perfectly precise test (which would be impossible to design really, there's too much variables that you cannot account for (when was the wind blowing and where, if the wind data on Strava was correct, road surface, line taken in the corners, draft on Zwift etc. etc.). More than that I was attempting to do an experiement if these climbs are reasonably close (in other words, if someone who does it on Zwift can really honestly say "I've done that!"). I tried to account for all the possible things that I could think of but it was never meant to be 100% perfect. Thank you for your comment, love discussions like this!
@@RoadtoA thanks for your respose. I recognise that you attempted to address the variables but I do think that this error should completely change your conclusion. I think that the wind effect is would be near zero at your bike speed in light winds however, I don't know the local airflow conditions. Therefore, I think you should really repeat the Zwift Alpe using the actual power figures then compare again. It also gives you an excuse to make another video 😏and get more vertical metres toward your concept bike 😛
“Climbing” on Zwift without elevating your front wheel or using a Kickr climb is just like riding on the flat in a headwind using your same non climbing muscles. I think you dropped the ball by not engaging more of the upper hamstring. This would affect your power.
While that's true, it would affect only my maximum power, which I wasn't doing. Similarly how the altitude would affect my maximum power. And I wasn't doing max power. That's besides the point of this video though - here I was merely comparing the two climbs - my performance is irrelevant.
Have you considered fluid loss during the effort? I normally would lose 1-2 lbs of weight by the end of an hour effort. Curious to know if that effected the latter portion of the climb
@@ralzalychhoeng7893 Might have had a little bit of an effect, good point. But it wasn't like a crazy effort for me, so I wouldn't say it was this whole difference.
Very interesting well done. I would like to know though how it felt to you as you rode the real climb out side like for effort and leg feel etc compared to Zwift. For myself I can put out more power outside and feel less fatigue than when I am on Zwift. Like to hear your thoughts on this. Thanks for your effort here with this Video.
@@barryhambly7711 I didn't ride in a maximal effort so take this with a grain of salt but the feeling is fairly similar, IMO (obviously, besides the air being fresher etc.). I myself can also produce more power outside but in my case it's probably due to insufficient cooling indoors. Do you have powerful fans?
@@RoadtoA Hi thanks yes I have three small turbo fans so I am OK for that / 2 in front and 1 behind the bike. With me I just feel fitter and stronger at push the power through the Peddles out side and less fatiguing
Great Video. If Riders want to replicate a Real Life climb they do need to consider bike weight, clothing, water bottles, etc. Zwift only uses your body weight and that means you are outputting far greater w/kg than you would IRL
I think you missed one variable - air density. Not for resistance, but for oxygen intake. The Alp d'Huez is ascend is between 600 and 1860 meters altitude. Not altitude acclimatized you would loose from 1 to 11 % power at these altitudes compared to sea level. (I have no data on the altitude of your indoor cycling....) * data from a TrainingsPeak coach blog article.
I kind of wrong of course - and I should have waited to the end of the video, instead of reacting to your intro. The altitude affects the power that you can put out, not the power that is needed for the climb. But if you go by feel, it should be 10% easier on Zwift at the top. At the speed you ar traveling air density should not make enough difference to matter for the resistance.
i would to see changes in heart rate during your workout. Well if air is thinner and you are going faster then how heart rate is reflected. please if you have this data it would be perfect to add them to table
@@AutoRitYLNX add me on Strava (link in bio) and take a look at the activity - it was on August 12 - all my data is accessible there. To compare it between indoor and outdoor doesn't make sense as there's too many variables.
Have you really stopped there? I mean, it's a great comparison to Zwift, but the official Tour de France finish line is two more kilometers to go. Hope, you did it the (full) climb (again) for your records.
@@Bradbajc I should have clarified better. The adjusted power is the Zwift power to which I added the power I would need to do to overcome the wind that was outside - so the two attempts are comparable as just climbs.
@@Bradbajc you didn't watch the video, did you?;) I go into detail how I came up with it in pre-test section of the video so it is probably better if you watch it rather than me trying to describe it in the comments.;)
@@charliegalliher people get that impression because they compare the climbs as they are. But your equipment in game is really way lighter, which plays a role on such a climb.
@ $20/month. No, no i cant experience the fake sensation of turning my TV into nature video that only shows roads, but only when i pedal my bike on some overly convoluted contraption. Ill take a real breeze thank you, even if the wind presents quite a challenge for my novice patootie. Maybe in 20 years when some phenom makes all this software free I'll enjoy retirement cycling indoors. Im certainly not paying more than a paramount+ subscription, so im @ like $5 a month. If a company's price is 400% more than my willingness to pay, I cant get sold on the idea. All i can do talk about it.
Have you done the real thing? How was it? How did it compare to Alpe du Zwift for you? Let me know in the comments! ⬇
Done both and went about 8 mins faster indoors, without having to focus on conditions I pushed a lot more power indoors(ANOTHER 20 WATTS) . I went looking at my zwift times to find a similar performance. Used 25 watts less and was still 30 seconds faster. 35 watts less and I was 25 seconds slower.
Rode it yesterday actually. (Sept 14). It was windy when I rode it. On some of the longer stretches I had a headwind which sucked. And not much help otherwise.
I felt like it compared pretty good in terms of the pitch
Finished in a time of 1:01:01
@@TheTurdFerguson nice! Hope you at least enjoyed the scenery!
You've went in great detail the weights, wind etc. You've probably done it the most scientific of everyone who does Zwift. Well done
@@scottmccann4509 thank you!
Very nice video, great approach to the experiment. To replicate the effort, and not have to trouble yourself with other factors, you can stick simply to wattage. By this, I mean you can take the file from your Garmin/Strava, break it down to only have the section for the climb itself (so you would need only to know when you had start/stop signs on the FIT file). Then you can upload it to Zwift as a Custom workout, approach the bottom of Alpe d'Zwift and start the workout there. At most you would lose like a second, in terms of wattage synchronization, and saves the hastle of all the other calculations. I did it a long time ago with Ventoux, it worked pretty well (apart from the fact that I broke down in tears inside, because I forgot to turn on the fans and it got REAL hot, REAL fast haha). Take care and ride on!
Holy hell, that didn't occur to me at all! That would be actually easier!
I've always wondered about the climbing comparison to Zwift and outdoors! As someone who lives nowhere near any sort of mountains, it's nice to know that Zwift translates well.
This was such a a great idea for a video! Seriously impressive work, Adam!
Also, love the pup making a cameo 😂
Thank you, glad you liked it!
I was wondering of someone notices him! 😂
Great video. Love the graphs and great to see that the time difference is so little! Also you have chosen a perfect day for this comparison ride. When I did the alpe it was the heat that got me, it was like cycling in a oven. :D
@@RideWithGerben thank you! It was pretty watm on the day but I did it late in the evening so the climb was in the shadows a lot.
Great comparison - for those of us that don't have the real thing in easy reach, it's great to know that AdZ is a decent enough emulation in terms of effort to be able to do it and still feel some sort of achievement.
@@robtempest8900 thank you!
Excellent video, well done to put down that much work for other zwifters. You deserve more views !
Thank you very much!
Very cool what you did, congratulations!!
Thank you very much!
Bravo to you! Great job comparing, and I always wondered when doing this on Zwift. You are lucky to do the real climb! Thank you for all the hard work!
Thank you!
Outstanding video, thank you. Reassuring too, for those of us who haven't been lucky enough to ride the real thing ... yet!
@@TheRmr23 thank you!:)
Really good analysis on something I've been curious about since joining Zwift.
@@sgp7975 thank you!
Well done! Of course when I got the chance to ride the real Alpe, I had a difficult time pacing because I was so excited to be riding the actual legendary climb. Doing it in the basement isn’t quite the same.
That's true, the excitement is real'
Very interesting, impressive all the time and thought you put into this. Well done.
@@NeonGrayEdits thank you! 🫡
This is an amazing video comparing the two
Thank you!
Amazing work and very interesting ! This is always a question I asked myself regarding the representativeness of an effort on a virtual platform (Zwift or rouvy for instance) ! Thanks a lot !! 🚲🙏
@@sylvaina.2455 thank you!
Never ask chatGPT to do calculations :).
The problem is that 7.3 kph refers to speed at a 10 meter height. At ground level there's ground sheer, and wind speeds are much less. Also as you point out the wind comes from different directions. So you should average the effect of cross-wind, headwind, and tailwind, with appropriate weighting factors. The end result is that that amount of wind has only a small effect.
@@djconnel Like I said - I know it's not an absolute test of the accuracy (I don't even have a way to verify the validity of the wind data). My aim was to assess if AdZ is reasonably close. There are just too many variables to do a scientific test.
Managed a 1hr15m on the climb (on borrowed road bike) after a morning of Mega Practice back in July, Zwift on a Wahoo Kicker Move + Climb and I’m around 1hr25m
WFH + Zwift really help me train, but the real world always give me that extra push
@@mattmace9917 It really is motivational! Glad you enjoyed it!
What a great video. 👍
Thank you!
Amazing approach!
Thank you!
GCN did the same, I believe on Zwift with 2 different riders. Zwift they were on average 5 minutes quicker but they did mention on calibration on Zwift correctly.
@@davidcarino6500 I'll watch their test!
Nice work & cool video!
@@JohnMueller thank you very much!
You get a very good feel for the gradient, means you know you can do it. The rest is not comparable IMHO. Done it 43 times on zwift, twice in real life. Real life is best!
It's not meant to be an ultimate comparison. Just basic, rough, "is it close enough" thing.:-)
I agree that outside it is incredible.
@@RoadtoA you're correct, you really can't compare indoors with outdoors, basic/rough is all you can fo, too many variables outside, more than you did well to compensate for.
Nice job!
Thank you!
Great video. But I have a question. What was your "trainer difficulty?" Default 50% or did you set it to 100%? I haven't climbed anything really big on Zwift since I did the Alpe a couple years ago, so I don't know if they've made any changes. But when I first started with Zwift I set it to 100%, thinking that would give me the most realistic experience. What I found was that climbing seemed much harder at the same gradient than it did in the real world. I then set it to 50%. To me that seemed much closer. So what was your setting?
@@Enigma71559 Trainer difficulty is irrelevant, lower TD only makes the climb feel easier but you still need to produce the same watts to go up.
But for what it's worth, I use 100% trainer difficulty because in my opinion that gives me the closest feeling to the real thing.
Nice explanation
@@frannyyarina
Nice video and it was interesting, however, I think there is a fatal flaw in your argument. I believe that you asked the wrong question of ChatGPT. I think that the answer it gave to your question was the power lost to all air resistance. Zwift calculates the power lost to air resistance as we know when we try to cycle fast. What you wanted to know was only the power lost that was directly attributable to the 7.8kn wind: which as you correctly state, is not included in Zwift's algorithms. Furthermore, your ChatGPT answer says that it assumes the worst case i.e. it has made its caculation on a constant headwind of 18.3km/hr which is completely wrong. I'm sure that the wind would have an affect on your time but it would be much less than the 10% you state. Wind direction would also be a very important factor. I do agree however, that the road surface would be important, perhaps more than you have accounted for.
Oof, there's a lot to unpack here. I think your argument is fundamentally right, it makes sense to me. That said, it was not meant to be a perfectly precise test (which would be impossible to design really, there's too much variables that you cannot account for (when was the wind blowing and where, if the wind data on Strava was correct, road surface, line taken in the corners, draft on Zwift etc. etc.). More than that I was attempting to do an experiement if these climbs are reasonably close (in other words, if someone who does it on Zwift can really honestly say "I've done that!"). I tried to account for all the possible things that I could think of but it was never meant to be 100% perfect.
Thank you for your comment, love discussions like this!
@@RoadtoA thanks for your respose. I recognise that you attempted to address the variables but I do think that this error should completely change your conclusion. I think that the wind effect is would be near zero at your bike speed in light winds however, I don't know the local airflow conditions. Therefore, I think you should really repeat the Zwift Alpe using the actual power figures then compare again. It also gives you an excuse to make another video 😏and get more vertical metres toward your concept bike 😛
“Climbing” on Zwift without elevating your front wheel or using a Kickr climb is just like riding on the flat in a headwind using your same non climbing muscles. I think you dropped the ball by not engaging more of the upper hamstring. This would affect your power.
While that's true, it would affect only my maximum power, which I wasn't doing. Similarly how the altitude would affect my maximum power. And I wasn't doing max power.
That's besides the point of this video though - here I was merely comparing the two climbs - my performance is irrelevant.
great comparison, what trainer difficulty level? Also you should have done the downhill, you'd expect Zwift to be quicker but maybe not.
100% trainer difficulty.
Zwift downhill is WAY faster - no cars, no need to break, no risk of death.:-)
Have you considered fluid loss during the effort? I normally would lose 1-2 lbs of weight by the end of an hour effort. Curious to know if that effected the latter portion of the climb
@@ralzalychhoeng7893 Might have had a little bit of an effect, good point. But it wasn't like a crazy effort for me, so I wouldn't say it was this whole difference.
1-2 lbs in hr? I'm lucky if a lb. I'm pretty lean.
Awesome video.
Thank you Ryan!
for the algorythm :) Nice comparison btw!
Thanks!
Must have been a massive pain in the arse putting this together
@@matt99is I like editing. But it was quite complex, yea;)
Very interesting well done. I would like to know though how it felt to you as you rode the real climb out side like for effort and leg feel etc compared to Zwift. For myself I can put out more power outside and feel less fatigue than when I am on Zwift. Like to hear your thoughts on this. Thanks for your effort here with this Video.
@@barryhambly7711 I didn't ride in a maximal effort so take this with a grain of salt but the feeling is fairly similar, IMO (obviously, besides the air being fresher etc.).
I myself can also produce more power outside but in my case it's probably due to insufficient cooling indoors. Do you have powerful fans?
@@RoadtoA Hi thanks yes I have three small turbo fans so I am OK for that / 2 in front and 1 behind the bike. With me I just feel fitter and stronger at push the power through the Peddles out side and less fatiguing
@@barryhambly7711 I have the similar feeling outside!
Great Video. If Riders want to replicate a Real Life climb they do need to consider bike weight, clothing, water bottles, etc. Zwift only uses your body weight and that means you are outputting far greater w/kg than you would IRL
@@daveoram7249 exactly!
I think you missed one variable - air density. Not for resistance, but for oxygen intake. The Alp d'Huez is ascend is between 600 and 1860 meters altitude. Not altitude acclimatized you would loose from 1 to 11 % power at these altitudes compared to sea level. (I have no data on the altitude of your indoor cycling....)
* data from a TrainingsPeak coach blog article.
I kind of wrong of course - and I should have waited to the end of the video, instead of reacting to your intro. The altitude affects the power that you can put out, not the power that is needed for the climb. But if you go by feel, it should be 10% easier on Zwift at the top. At the speed you ar traveling air density should not make enough difference to matter for the resistance.
@@EJD2012 Exactly! :) But if I did this test all-out, that would absolutely be a factor. Great point regardless!
That was amazing, a really creative idea to do it side by side and I loved the idea of using Chat GPT to do the calculus.
Keep up the good work 👏
Thank you! :)
If you need to use 240 watts to avoid falling over while climbing, you need better gearing.
Not really to not fall over but to keep a comfortable cadence.
i would to see changes in heart rate during your workout. Well if air is thinner and you are going faster then how heart rate is reflected. please if you have this data it would be perfect to add them to table
@@AutoRitYLNX add me on Strava (link in bio) and take a look at the activity - it was on August 12 - all my data is accessible there. To compare it between indoor and outdoor doesn't make sense as there's too many variables.
ChatGPT can't really do math - its just very convincing. So unless you can get someone to verify the calculation, I would assume it's false.
I read through its calculations and it made sense to me.
Does bike weight matter indoors?
@@wm.b.bowman2634 yep! That's why some bikes on Zwift are better climbers than the others.
Have you really stopped there? I mean, it's a great comparison to Zwift, but the official Tour de France finish line is two more kilometers to go. Hope, you did it the (full) climb (again) for your records.
@@macx yup, I did the full thing, I stopped here because this is the 'Zwift finish' :)
What about altitude? Wouldn't you lose 10 to 20% power there?
Only off your MAXIMUM power. If you are going in submax power (as I was in here) it does not matter (it is just a little harder in terms of feel).
Do Rouvy next?
I've got virtual shifting, so I believe I am locked to Zwift for now.
@@RoadtoA Rouvy is more realistic that the Zwift climb. Too bad you locked yourself into Zwift. All the climbing is on Rouvy
@@edwiser for now...:) Doesn't mean I won't try different platforms in the future.
@@RoadtoA As I work with all the platforms I can tell the answer is no.
How do you convert "zwift power" to "zwift power adj." ? - power is power.
@@Bradbajc I should have clarified better. The adjusted power is the Zwift power to which I added the power I would need to do to overcome the wind that was outside - so the two attempts are comparable as just climbs.
@@RoadtoA How exactly do you calculate this? How can you possibly know how much power you need to overcome the wind?
@@Bradbajc you didn't watch the video, did you?;)
I go into detail how I came up with it in pre-test section of the video so it is probably better if you watch it rather than me trying to describe it in the comments.;)
Q.I. 👍
@@Nial_Q 🤜🤛
I'm surprised - I thought zwift would be a lot faster....
@@charliegalliher people get that impression because they compare the climbs as they are. But your equipment in game is really way lighter, which plays a role on such a climb.
No. End of video. 3sec
Aight.
I hope you don’t wear those ear buds when you ride
@@karenjones3051 of course not;) I had the bone conduction headphones in the past but the last year I don't wear any.
Lee Amy Jackson Anthony Davis Elizabeth
@@madisonoldman6772 I'm trying to decode this message but so far I am out of luck.
@ $20/month. No, no i cant experience the fake sensation of turning my TV into nature video that only shows roads, but only when i pedal my bike on some overly convoluted contraption.
Ill take a real breeze thank you, even if the wind presents quite a challenge for my novice patootie.
Maybe in 20 years when some phenom makes all this software free I'll enjoy retirement cycling indoors. Im certainly not paying more than a paramount+ subscription, so im @ like $5 a month.
If a company's price is 400% more than my willingness to pay, I cant get sold on the idea. All i can do talk about it.
I respect that.
Oh yeah I did that in realty:) Good job to you! I did create my own take on the experience, check it out if you feel :) Kudos and Ride ON!
dudeee😂😂 youŕe one crazy mofo
joking aside, that was hilarious
@@RoadtoA Thanks! Was hell of a fun experiencing and creating it too :)
@@NoStarCyclist ye and I think this fun-style is niche that really is missing in the pool!
@@RoadtoA Let's see if it even is a "niche":)
@@NoStarCyclist everything is a niche if you are stubborn enough 😅
Cool idea. I was interested to know about it. Thanks for this work 🫶🏻
@@lukasmobus3024 thank you!