CycleOps SuperMagneto Pro speed issues

Hi. Please help. This is my set-up. I have a CycleOps SuperMagneto Pro trainer with Wahoo Speed and Cadence Sensors. I spoke to some zwifters about my effort levels and they told me something must be wrong.

I have my trainer tire with around 110psi and I am going with road (2) setting.

I am going at about 18mph on my sensor on average but Zwift only calculates about 100 watts on average during the same ride.

Is this ok? Maybe I am just really unfit lol.

But if not, what can I do to adjust it to a more accurate reading?

I found my trainer’s power curve according to the manufacturer:

I know Zwift is probably using different values and I don’t expect a full match with what this curve says but the difference is stark… I should be going at around 160.

Any ideas on how to fix it? It´s really frustrating having to labor so much to keep up on even the slowest of group rides.

I tried using the same trainer using the interval setting. I was gassing myself out and doing around 80 watts in Zwift. I did not try the other settings. I bought a kinetic smart trainer that was on a “covid 19” sale in March for $350. You can try the easy setting but would be better off going with a smart trainer sooner rather than later if you really want to use zwift.

Thanks Gene. A smart trainer is not an option, budget-wise, at the moment. But thanks for replying. .

You say you are using setting 2, so try setting 1 or 3, see if you can get results closer to what the graph says. That’s really your only option.

Hi Ben. Supposedly setting 3 makes it even harder so I doubt that was going to work. So I tried setting 1 and this seems to at least give a bit more realistic reading.

Now, while doing roughly the same effor as before, my speed wheel goes from 17mph to about 20. Thats average off course. And the jump in estimated power is stark. From about 90 to 160. It makes going on rides much more enjoyable.

I get the impression It is overstimating my actual output but I can feel it is more realistic. I will go forward like this until I can get myself a power meter or a smart trainer.

Thanks for your help.

Hi Gene. I would like to ask you. Now with your smart trainer, doing roughly the same effort you did with the dumb trainer, how many watts is it calculating?

The best guess is about 180-200 watts. It’s hard to say though as I have only been doing Zwift courses with all the ups and downs. On the SuperMag I was just doing 30-45 minute steady efforts.

That makes sense with what I am finding. Thanks

The correct setting for Supermagneto Pro is 2 (road). I think something has changed with Zwift’s calculation for this trainer. It used to work really well, i rode on Zwift for over 1 year with guys i ride in real life and we concurred my power/speed relationship was very realistic (they have power meters, i’m using the Supermagneto Pro). But recently (since about July 2021) my zpower wattage calculation has dropped dramatically even though the trainer resistance and function feels the same as before. So i purchased new Garmin sensors (HR, Speed, Cadence) thinking my Bryton’s were dying, but there’s no difference, the power is still crazy low - like half what it used to be at best. I reinstalled Zwift onto my laptop, that didn’t help either. So hmmm… not sure what i can do next.