Zwift and the power conversion for the Erg.

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Carl Watts
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Zwift and the power conversion for the Erg.

Post by Carl Watts » November 24th, 2021, 10:24 pm

Okay so I have been using a bit of Zwift using the Concept 2 Erg and the RowedBiker App.

Overall its a great experience however the power conversion really isn't great with just some fixed percentages to use.

So far I have only done 80Km on Zwift using the 50% power boost option which would appear to be about right but only for a narrow range of pace at around 2:00 on the Erg.

What I would be really interested in is have you looked at your peak power on the Bike trainer compared to the peak power on the Erg ?


You would need to have a decent bike trainer not a pile of crap. Something like a WattBike or Tacx NEO or Wahoo Kicker or the likes.

The fixed wattage percentage conversion doesn't seem great, I suspect that it needs a correction curve. Ideally you would do a test on a bike, look at your peak Watts and then jump on the Erg and look at your peak Watts and whack the correction factor into the top of the curve.

I'm picking that at 1:20 pace on the Erg you need about a 100% increase in the power on the Erg translated to get to the equivalent effort on a bike.

At the other extreme say 2:40 pace on the Erg you may need as little as a 5% Boost. Its clearly not a linear function as a conversion.

If anyone has the time to jump on both the Erg and the Bike and post the results here with your height and weight it would be interesting to discus it.

Unfortunately I don't have access to a bike at present but I suspect that for a maximum power test, most people are going to be able to put out twice the power on a Bike as they can on a rower.
Carl Watts.
Age:54 Weight: 108kg Height:183cm
Concept 2 Monitor Service Technician & indoor rower.
http://log.concept2.com/profile/863525/log

MartinSH4321
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Re: Zwift and the power conversion for the Erg.

Post by MartinSH4321 » November 25th, 2021, 3:48 am

I think you overestimate the difference.

Looking at world-class-performances:
max watts on a bike: 2378W for 5 seconds
max watts an the rowerg: not 100% sure, but some guys came sub 1:00 pace, so propably around 1700W

hamish bond, world class on both bike and erg, for 1h:
bike: about 480W
erg: about 400W

Some very strong erger on both rower and bike said that 2k is about break-even-point, shorter distances better for the rower (except 100m) and longer distances better for bike.

I use the C2 rower and a Daum ergobike 8080 which is high quality, some comparion:
around 70% of MHR I can row around 180W and bike around 220W
30' PBs are around 270W row and 330W bike
5x1500m/5'R on the rower around 300W
5x6'/4'R on the bike (so ca. 1' longer and 1' less rest) around 320W
1983 Austria 1.86 103Kg
LP: 1:04.6 100m: 13.6 1': 392m 500m: 1:21.4
1k: 3:05 2k: 6:43 5k: 17:53 30': 8237m 30R20: 8088m 10k: 36:39
60': 16087m, HM: 1:19:42
Insta-Training log/vids: @martin.stoeger

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Carl Watts
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Re: Zwift and the power conversion for the Erg.

Post by Carl Watts » November 25th, 2021, 1:16 pm

I do agree that longer bike rides (which can be typical in Zwift) are easier than longer rows. A couple of hours on a bike can be quite normal, a couple of hours on the rower is not as common.

Yes its impossible to come up with some generic conversion, it needs something you can put your personal results into to make it a bit more accurate.
Carl Watts.
Age:54 Weight: 108kg Height:183cm
Concept 2 Monitor Service Technician & indoor rower.
http://log.concept2.com/profile/863525/log

Claudius
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Re: Zwift and the power conversion for the Erg.

Post by Claudius » November 26th, 2021, 4:09 am

I also have written on the FS Page a small summary about rowing on Zwift.
https://www.freespiritsrowing.com/forum ... f=7&t=3779
The Powerdata values changes - they are volatile - even if just been viewed out of perspective of one sport - cycling only - if compared to another sport things get really fast out of hand. I had a cycling FTP in summer measured outdoors with Shimano 9100P of 333w- now with focus nearly on rowing this is more @305-315w compared to rowing 280w. If i would refocus on cycling the 333w would be back in 4-5w. If you want to race on Zwift with the rowerg (seriously racing in terms of competing against others), you quickly realise that this is absurd- because it is simply not cycling. For this reason a virtual water world on zwift could make sense in terms of competing rowers vs. rowers. But if the majority of your training is low intensity, it is just fun having a cycling avatar (thats not me then, i am rowing, the avatar is cycling) cruising around.

Yesteday Eric Min on his Thanksgiving ride: " I think rowers would have more fun being a cycling avatar. Maybe we just need to give them some handicap."

My journey with that avatar was also supposed to be a friendly provocation to Zwift reminding them to integrate rowing...but turned out to be something completely different to me.When you play a game in which you take on the role of someone else,then you are also training the right hemisphere which interacts then with the left...and puts some dots together.

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Carl Watts
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Re: Zwift and the power conversion for the Erg.

Post by Carl Watts » November 26th, 2021, 4:49 pm

I guess another problem is the level of "Training"

Imagine only a well trained or even an elite level cyclist switching to rowing and getting a power result comparison and they had never been on a rower. If they were in RowPro they would most likely be in trouble in producing a decent result.

So now go the other way where someone in Rowing has not got on a bike for 30 years and your in Zwift trying to ride with trained cyclists.

I guess its impossible to get a decent power conversion and hence thats why Zwift was going to bring out rowing but unfortunately it died.

For now I will just run the 50% power boost option, this looks to be about right for a range of pace on the rower from about 1:58 to 2:04 when I consider the rating is 16 to 20spm for me.

This allows me to chase 300W for up to an hour.

Even after using Zwift for only 80Km the only major problems seems to come at the flat out sprint pace.
Carl Watts.
Age:54 Weight: 108kg Height:183cm
Concept 2 Monitor Service Technician & indoor rower.
http://log.concept2.com/profile/863525/log

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