Resistance Increase ERG Mode Issues

Tonight during the SST Med workout the resistance increased progressively towards the end of the workout. The target wattage stayed the same, but the resistance at the trainer noticeably increased well past the target wattage.

Here’s how I can best describe it: To get back to what felt like the target wattage resistance, I would have to increase cadence so much that it would put me well above the target cadence. And when the workout was done and I was in the cool down sections, the resistance was so high that even at the target of 180w I was barely able to push the pedals. To hit the target 180w I had to drop my cadence to below 50rpm.

One interesting note: During the cool down block I paused the workout so that I could do my own cool down at a decent cadence. When resuming the workout after approx 3-4 min of easy spinning the cool down block resistance seemed much more manageable. 

It’s almost as if the flywheel in my Hammer builds up an amount of resistance over the course of the workout and the beyond-ERG resistance came to a head at the very end.

I’m up to date on firmware, and I did notice the same problem (albeit much less pronounced) when I did the “McCarthy Special” workout in ERG mode last week.

Any recommendations besides turning off ERG? Thanks.



Have you done a spindown for your trainer? I believe that’s possible through the CycleOps Virtual Training software.

We aren’t aware of any issues with Zwift sending the wrong ERG commands to a trainer, so aside from making sure you’re using it as recommended - the areas I’d recommend checking are trainer related. Usually, they’re either missing commands due to signal dropouts or having problems due to calibration or hardware issues.

Hope this helps point you in the right direction!

I calibrated two weeks ago, so I don’t believe that’s the issue. And I don’t believe I’m losing signal because I don’t have wattage drops. Plus, as I stated, the resistance went back to normal when I paused the workout.


I am having this same issue with the Hammer, I either spin at 130 cadence or below 50, the resistance builds up so much I actually had to get off due to how hard it was to move the pedal.


I’ve found that, when doing workouts in ERG mode, if I keep my cadence slightly higher than 95rpm I don’t feel a resistance build up.

Personally, I don’t mind spinning that high, even during a hard interval block. If you are literally having to hold 130rpm during an interval I’d say that it’s either a calibration problem, or you should try lowering the FTP. 

Also, I spoke w/ some people at Saris/CycleOps and linked them to the comment threads where users are expressing their displeasures w/ the Hammer and the Magnus. Hopefully that will motivate them to address issues a little faster, but we should all remember that both Zwift and Wahoo have had a few years now to work out the kinks w/ the Kickr (and it’s still not perfect) so we might just have to exercise some patience.