Trainer inflating power on steep "incline"

Hello… apologies if this has been posted elsewhere. I’m training for a long steep climb (~7 miles at 12% grade) by doing a lot of low candence work since I won’t have great gearing. I’m training on my Wahoo KickR using Zwift, FulGaz etc. Yesterday, I used FulGaz on Mortirolo and my power on my Wahoo KickR was too high by ~20 watts (275 vs 255) vs my Assioma’s. I notice this happens in Zwift too when I do the radio tower climb (i.e. if the grade is very high, then my trainer inflates my power vs the pedals). Has anyone else had this issue? I realize I should just set my power to be off my Assioma’s but was wondering what’s going on.


Using a single power meter - your Assioma pedals - is the right way to avoid the problem. I’ve got a Kickr 2017 and noticed that power estimates vs Stages (left) will vary over a 1 hour workout. My guess is that as you virtually climb, the flywheel is heating up and that impacts the accuracy of the Kickr’s optical power estimation. It is just a guess, so ignore that and focus on having a single source of power to avoid the problem.

Power data differences between devices is common and nearly inevitable, unfortunately. There are MANY topics posted here with similar differences. At this point, people should expect them NOT to match, and be extra happy if & when they do match or are close within defined tolerances.

Since you have the power meter pedals on the same bike as you are using on the trainer, using TR PowerMatch is the best option for data parity when you ride outside.

yep understood. the differences are significantly magnified when the trainer simulates a steep gradient (and I didn’t see prior posts on this topic) and only then are the readings between pedals / trainer outside the margin of error.