Does the Xert app get bored?

Sometimes I’ve had catastrophic results while using the Xert Android app (on a Samsung Galaxy Note 4) to control my Tacx Neo Smart in ANT+ FE-C mode with power match against my Verve InfoCrank Classic power meter, set up according to . I’m not sure, but it feels as if long periods of static resistance will make the app loose its concentration, as if it gets bored or something…

Yesterday I did a recovery/endurance workout where I was targeting 195 W for the first hour, then two 2 minute efforts in zone 4 twenty minutes apart and then back to 195 W again. It was spot on for the first 20 minutes, when I decided to gear up to the large chain ring and lost some power while revving up again. After that it was constantly undershooting power, having me output about 180-185 W instead of my target of 195 W. It ought to aim for 200 W for a while in order to get me back on target.

But then after an hour, I was about to do my 2 minute effort and that’s when it really messed up. It beeped saying it wa s time to do an interval, but kept me riding at 180-185 W! Nothing happened. I stopped pedaling, ended the activity, closed the Xert service, restarted the app, opened and restarted the workout, skipped the first hour of the workout and got back into the 2 minute effort and… nothing! No difference. So then I forced the power up by pedaling like crazy for a while, but it forced me back down until gradually increasing the power and after about a minute it felt like the resistance was about right. At the end of the 2 minute effort, it beeped and resistance dropped immediately to 195 W and kept me there for the next period of about 20 minutes. Spot on, as I recall. Then the second 2 minute effort came up and… nothing! No difference, no reaction. I did the same thing, I pedaled like crazy and it forced me back down, but after a while realized that it was way off and gradually and slowly increased the resistance for about a minute. At the end of the 2 minute effort, it immediately adjusted resistance to 195 W again…

This is not good, you need to have a look at this! Do you have some kind of drift or does the software lock up in some kind of loop and is unable to adjust resistance?

Hmm… Suspect it might be the powermatch algorithm. Are you able to try with powermatch off?

Previously I did use Xert app without PowerMatch and only using power data from the power meter (not the trainer), but then I read the blog post and did it that way instead. What would happen if I would receive power data from both but disable PowerMatch? I’m not sure how it works, but I’m thinking that if the power meter reads 200 W and the trainer reads 192 W, while Xert is aiming for 195 W, you would tell the trainer “give me 195 W” and I would end up on 205 W on my power meter? Correct? Not the result I’m looking for… No offense, but I’m more in the line of asking you to check your algorithm for bugs.

The algorithm automatically calibrates your trainer with your power meter. The calibration is quite involved as it looks for both the slope and the offset to make both power and transitions more accurate. It relies on variable data in order to establish the slope and offset. For the time being, I would suggest you turn Powermatch off if you are still experiencing any issues until we have an opportunity to test and investigate some more and then to address the issue. Thank you.