Control smart trainer's resistance with external power meter - important for Workout Mode

(A Simashin (B)) #101

Nah… Spring is comming.


(Brian Dixon) #102

Zwift team: do you have an update?

(Peter Schindler MGCC) #103

I think this is a very important feature and I hope that you move on it quickly. The workout functionality has a lot of potential, but without being able to use an external power meter, it’s not good for doing truly targeted workouts.

Can you provide us with an update on progress?

(Sunil Savkar WBR (C)) #104

I am surprised that this has been requested for over a year, but there is nothing further stated by the Zwift team here??

I just recently got a KICKR Snap, discovered Zwift and was hooked.  But then after starting with a basic 6-week workout and deciding I wanted to match up real world rides with Zwift, I got myself some PowerTap P1 pedals only to find out I couldn’t use the P1 pedals as the power source while keeping the Snap as the controlled trainer in ERG mode.

Seems like a major issue that really needs to be fixed.  Else like others have noted, I suspect I will end up swapping to another option like Trainer Road to get a better experience with consistency in workouts and measured power levels/output.

Can someone from Zwift explain what the issue is?  Sounds like early on the concept had been implemented but then was later removed, which is strange to have done without any explanation?

(A rider) #105

Welcome to Zwift Sunil… hey at least we got a LAVA course. Thanks Eric!

(Sunil Savkar WBR (C)) #106

Ha ha!  Fair enough.

Actually reading around a bit more, I think there was another thread where more was stated as to why there were difficulties getting this re-implemented.

Though oddly other programs (Trainer Road in particular) apparently figured a way through.  Though even there i understand it isn’t perfect and some have complained about lag issues between readings at the pedals and response time on KICKR.

Anyway, with the advent of so many power meter options, seems like a really important item to try to address if possible - suspect smart trainer manufacturers like Wahoo and then powermeter companies like PowerTap should be more than willing to work with Zwift to help them figure out how to match up at least certain products to start.

Like the KICKR/Snap and the P1 pedals.  :slight_smile:

(Brede Arntzen) #107

Without ERG mode with a separate power meter input Zwift is a toy. I use PerfPro to control my tranier with PowerTap input and use Zwift as a fun-to-watch thing in parallel. PerfPro receives power readings both from my trainer (Tacx Bushido) and PowerTap and the trainer varies between 5 and 10% off. I dont care to calibrate it either as it not needed as long as PowerTap and PerfPro are in charge. PerfPro is a one time charge of $99 - take one month off with Zwift and you have all you need.

(Sunil Savkar WBR (C)) #108

I am a tad confused how you do all of this.  So curious, when on Zwift, are you not letting Zwift control your trainer at all?  So does that mean essentially you are relying solely on power readings from your p1 pedals to determine based on the terrain how fast you then go?

I presume then that you use ERG mode with PerfPro and have it control things while simply being in “read mode” in Zwift.

Interesting.  Seems like I should be able to do that with a bunch of programs, right?  Even Trainer Road?  You prefer PerfPro?

Feels though that this gets a tad bit complicated no?

(Greg Hilton ARCC) #109

Sunil, you can set your P1 pedals as the power source, and your smart trainer as a controllable trainer. Zwift in ride mode changes the resistance based on the power readings given by the P1 pedals.

The issue is in workout mode where it turns off ERG if you have a power meter as the power source.

(Brede Arntzen) #110

Sunil, Greg answered your question. 
I only do preprogrammed sesions in PerfPro which controls my trainer and just make Zwift read the power meter (if paired with the smart trainer I unpair it not to get conflicts). So Zwift really du noting else than showing speed and W/kg.
I have not used Trainerroad but found $99 for one-time pay for PerfPro to be a cheap investment compared to monthly payments for Zwift and/or Trainerroad. 

(Greg Hilton ARCC) #111

there is no need to pay for Perf Pro, you can pair some of the Garmins to control the power using FE-C mode and use their workout creator, or Golden Cheetah can also do workouts and is free.

There is detail here

(Artak Sukhudyan WBR (B)) #112

I was using zwift more than a year and waited for more than enough, and just because of this switch to trainerroad.
It is 99$ annually as weel but 12$ monthly if you go month by month. Trainerroad is fantastic both structure workout plans and podcast as well. I was running zwift on my phone on parallel while running trainerroad on PC but later I found
I am not paying attention to zwift at all, thus cancelled my zwift at all. Very happy with trainerroad. The only time I found zwift is usefulll for me is to do races using my external PM.

(A rider) #113

So much traction on this today - my hope is for a flood of people telling Zwift to get their act together and prioritize their work flow.

It is boggles my mind that some people have some sort of “love” relationship with Zwift. They feel some sort of ownership and in a sense that they are a partner with Zwift on this “crazy ride” that is beta testing for payment.

I have gone through TR, PerfPro, Zwift, and CycleOps - used Golden Cheetah also. And honestly my demographic is more representative than any pro racer or high level rider out there. But, we are the most consistently ignored.

Zwift was the most “fun” for me, but I am cancelling my subscription because of the run around that is Zwift.

It is seriously like an Origin or Ubisoft video game except I am paying more.

Release Beta software, promise the moon, give you the finger. Constantly truncate the product to appeal to some micro demo - (VR as an example - really? VR?)

Oh well, at least I won’t feel compelled to read the fake upbeat, millenial tweets, derped out youtube videos, and FB posts - so intensely annoying and patronizing when I cancel.

“But Zwift is a community and we love them, they are us, we are a united ecosystem that thrives based on good vibes and harmonious relational interactions” you say.

Zwift is a brand that you pay money for, it owes you services, and accountability.

What I hope and “it may be happening”, is that a big player such as Garmin will just buy out Zwift and get stuff done (please not Garmin, please not Garmin). Maybe ICON Fitness - that would be a mess also. Oh well.

Or maybe Zwift should just hire some people and get it done and quit blowing wind up everyone skirts or pants or whatev.

(Brian Dixon) #114

A few comments:

Once you’ve used trainer road’s smart ERG mode you will ask yourself why Zwift hasn’t done this. In my experience its been a joy to use and is a great work around for “smart” trainer’s power accuracy problems. 

I think people are quick to point the finger at Zwift when this problem is truly a smart trainer problem. My “new” Wahoo Kickr is horribly inaccurate despite them claiming +/- 2% and saying they’ve fixed the problem with the new generation once and for all. I am talking 15% off compared to my Stages. Completely unexceptable for a $1,200 piece of equipment.

I think Wahoo and others should build “smart” ERG mode into their trainers hardware. Have the smarttrainer “read” your ANT+ power meter and use that data to drive ERG mode instead of their numbers. If trainer road can do it I dont see why a company like Wahoo, with nearly 100 employees, cant.

Everyone is quick to voice their frustration with Zwift to fix a problem caused by Wahoo and others. If Wahoo could actually achieve their accuracy numbers there wouldnt be anything to talk about!

(Brede Arntzen) #115

Bian. I think its is perfectly OK to point the finger at Zwift and not the trainer manufacturers. Most power meters like Stages, Power Tap and others do nothing but measuring the power exactly and stil they cost more than many smart trainers. Thus I dont find it too strange that the accuracy of smart trainers are worse than power meters.

Regarding Neo and Kickr that costs about the same as a smart trainer pluss a power meter I agree - they should be accurate.

(Erwin Kuipers) #116

Hi All, 

I have been using both TrainerRoad en Zwift for the last 2 months now. I have to say that I like Zwift the most because yeah, it’s fun and the time spend on a turbo goes by so much quicker. Combine that with my Strava addiction and there you have my bias! 

I am using a Stages Power meter for the last 3 weeks and I think I don’t fully understand the issue at hand, so please help me out here on the below best practice. 

First my setup:

  • Tacx Bushido Smart Trainer 
  • Stages Power Meter + cadens 
  • Wahoo Tickr
  • Using ANT+ dongle on a mac laptop

I have a trainer and I am using Today’s Plan to seriously manage data and planning. (Strava is just for fun). I love the export of a workout from Today’s Plan into Zwift, it works seamlessly and it strengthens my bias for Zwift. :slight_smile:

The best practice:
The other day I had to do a 3x 14 minute interval at around 95% of FTP (higher end of sweetspot). I figured let’s do it on Zwift instead of TrainerRoad and connected my turbo and Stages PM. 

You can see the results in the image. The “P” stands for power. It was 3 times spot on based upon power output. (Maybe I was a bit enthusiastic during the first interval).

So my question is, in regards to the topic at hand; was this an effective training yes or no? Can I be satisfied with the result or was it maybe ‘to easy’ because the Tacx Bushido doesn’t take the Stages power numbers into account during the workout in term of resistance? I mean, down the line I did 3x 95% FTP, right?

Let me know! I am curious in what you have to say!

PS: It’s regardless to say that I think that Zwift definitely need to fix this issue. The use of power meter will rise in the market due to the fact that powermeter will keep becoming more affordable for common riders just like me. Otherwise Zwift will still be a ‘fun cycling game’ instead of a serious training partner.

The Netherlands - Amsterdam 




(zzz Reeve GGCC D) #117

Hi Erwin.

Is the green line the stages power meter?

(Erwin Kuipers) #118

Hi there… yes, the green line is the stages PM.

(Clifford) #119

Still nothing … If you want cyclists to take your workout mode seriously, this is a must have feature! +1!

(Ben Conradi (BCC)) #120

You now have ‘Intensity’ arrows under the list of workout intervals on the left hand side but if your powermatch facility required is more than 10% it’s not much good as what Zwift call the ‘FTP bias’ (those arrows/adjustment on the companion app) is limited to 110%.