Noob question about Watts / FTP / and uphills

Hi! Im new to Zwift (and to biking!). I have a question about how watts work.

When I am on a ride, and going uphill (7% or higher), my watts decrease to about 50 and I cant get my MPH above 2mph - no matter how fast I pedal (120rpm). When on any kind of ride, I fall pitifully minutes behind everyone else on the uphills and there seems to be nothing I can do. I understand I am going uphill and shouldnt expect speed, but I am working really hard, and arent Watts supposed to measure the power I am putting in? My FTP is only 130 - is that the issue here?

I wondering if maybe I am calibrated wrong, or perhaps need to do another FTP test…

I see it’s been a while since your last forum post, welcome back!

If you are in SIM mode (not workouts, basically) and pedaling at 120 RPM on a 7% grade, I can only assume you should be putting out a lot more than 50 watts.

Check for firmware updates and trainer calibration. It’s best to calibrate through a first party app if possible, so the Wahoo Fitness app if you are using a Wahoo trainer, or which ever for the trainer you are using.

Also checking for interference in the area may help. All wireless communication can potentially cause it, and it’s often the cause of issues like this.

thanks. so you’ve confirmed the behavior is weird! I am on a Tacx Vortex and do a spindown test before every ride. Firmware updated. Are there other calibration tests I can do?

Not sure what mode I was in. If I am on a ride - i was on Herd Racing HBR12 this morning - would that typically put me in ERG or SIM mode? Ill check next time.

ERG should only turn on during workouts. The Tacx Spindown is the only calibration you should need to do. Make sure to unpair from the app and close it before pairing with Zwift so there are no issues with the signal trying to pair to both apps. If the issues persist, contact our support team so we can provide more in depth assistance.

Hi @Chris_Volinsky

What trainer are you using? I looked at your last ride and I see what you mean the road went up and your power dropped.

Do you change gears on the trainer also what bike do you have on the trainer?

Sorry for all the questions.

Im using a Tacx Vortex with a Specialized Allez bike. I typically do not change gears on the trainer, although I did try it today after seeing the low watt output to see if it would help. It did not.

Are you sure your wheel is not slipping on the trainer. Your cadence also seem high.

If using ANT+ make sure to pic the paring option with FE-C

dont think the wheel is slipping because the watts during level and downhills seem fine. only uphills are weird. Im using Bluetooth, so looking into if there are some kind of interference issues.

Thanks for all of your help. Seems like maybe my tire WAS slipping, I adjusted the trainer so I was now on the tight end of the acceptable range for the spindown test - it seems to have fixed the problem. Wont know for sure until I take a significant ride, but it looks like my watts are now behaving as expected.