workout mode adjust resistance

 I would like the ability to set the resistance level for Cycleops Magnus smart trainer in workout mode. In workout mode I prefer to be in the big chain ring, but after the july update, the resistance feel too high on the big chain ring. Now I have to put on the small chain ring and the cassette on 12-14.

Having the ability to set the resistance would let me be on the big chain ring and put the cassette on 13 during workouts.

But workout mode does set the resistance or more accurately it sends a power target to the trainer. Called ERG mode. The trainer will then do its best to hold that power. You can then ride in the smaller or larger chain ring and generally whatever rear sprocket that you want. The trainer internally adjusts the resistance to maintain the target power. I’ve got a Hammer trainer and prefer riding in workout (ERG) mode in the smaller chainring. This feels better to me plus it’s quieter as the flywheel is spinning slower.

This could be an issue you need to get in touch with Cycleops support.

@Nigel - before the July update, it did that correctly with cycleops magnus. After the july update, there seems to be issues with ERG mode. In a different thread, Zwift confirmed there was an issue with the latest firmware and Zwift not working together optimally. In ERG mode, the resistance feels way too high on the big chain ring. I have a compact and on 50x25 at 95rpm, I have to push 225 watts. The last FTP from zwift workout test was 243 watts, so that is a bit too high for my personal taste.

It could be this is just an issue with the latest firmware not working optimally with zwift and will be resolved soon. If not, being able to set a base resistance for ERG mode is another potential fix.

Wasn’t the issue that the spindown done within Zwift didn’t work properly on Cycleops trainers? That’s what I read. You should be doing the spindown from the Rouvy app or Trainerroad if you use that.

I did like 5 different spin downs. It didn’t make a difference. Hence the feature request. I keep thinking “maybe this spin down will fix it.” Sadly it doesn’t and the resistance is still the same, too high

You need to talk to Cycleops.

If I could roll back to the pre-july code that would be better. It used to work just fine. I’m a programmer and know how hard it is to get things to work correctly when someone else controls the code. I believe the other thread mentioned Zwift is actively working on the issue with Cycleops and it’s a known issue. Me talking to cycleops doesn’t actually help. Not unless I want to write my own Zwift, which I don’t.


I’m hoping the issue is resolved before the winter, otherwise workout mode is basically broken on Magnus.

Hi Peter. Your request will go nowhere. What you’re essentially asking for in your first post is when the workout power target is say 200 watts I don’t want the target being sent to the trainer to be 200 watts, I want it to be less. This of course doesn’t make any sense. The issue as I read it is your Magnus trainer will no longer calibrate correctly. Alternatively it wasn’t calibrated correctly before and now it is so previously it may have been overstating the power.

I assume you’ve seen the reviews on the Magnus?

As I mentioned before the issue Zwift is working with Cycleops with is about doing spindowns within Zwift. Until resolved you’ll have to use the Rouvy app, warm up the trainer for 10 minutes then do the spindown. This needs doing every time you use the Magnus. Good luck.


I don’t think you understand the feature request. I’m not asking for manual control of the resistance. I’m asking to set the base level and then let ERG mode handle the rest during workout.

Magnus works fine with cycleops app, but that doesn’t help when using Zwift. I can do spin downs until I puke, but it hasn’t fixed the issue. It worked fine before the July update, so the bug is in the integration. I didn’t update the magnus firmware before the july update. Once it stopped working correctly and set the resistance too high I updated the magnus firmware and did several spin downs. I’ve tested it with just cycleops app, without zwift.

I will try the rouvy app at the start, but again that’s not optimal. If I only have 30 min for a lunch workout and I have to spin for 10min before I do zwift workout, that basically means workout mode isn’t going to fit my needs. On the weekends I have the time to spin for 10 min.

I totally understand integration is tough and often full of difficult headaches. I specialize in integrating enterprise systems where nothing ever goes according to plan. Hopefully between cycleops and zwift, they can workout the issues soon. I’ve been subscribing since the start and really don’t want to cancel zwift. If it doesn’t meet my needs, I have better things to spend my money on like putting my kid through expensive college


I found a solution that works for me. No gaurantee it will work for anyone else with Magnus.


  1. start Zwift on the PC/Mac and login

  2. start pedaling in the big chain ring

  3. start zwift mobile link

  4. when the devices pair with magnus, continue to select the route and workout

  5. start the workout and wait 1 minute

  6. Start Rouvy app

  7. Start free workout

  8. Continue pedaling for a few seconds and the resistance “should” adjust

Definitely do not start rouvy before zwift mobile link. It will prevent mobile link from connecting properly. This is a guess on my part, before I start the free workout session, the resistance was still very high. A few seconds after I started the free workout session in Rouvy, the resistance adjusted and everything was back to how it was before the July update of Zwift.

My guess is Rouvy is sending the correct command to Magnus, with Zwift mobile isn’t doing. I may try to debug Rouvy to see what command it is sending to Magnus.