Would like to see a place to input my Circumference of Wheel to calculate Zpower. Currently riding a old Steel Bike on my trainer with a 27 x 1 1/4 " inch rear wheel .Thanks . You guys rock , awesome software !

+1 for me.

+1 from me as well but I am sure its already on the to do list at Zwift HQ

I have two options on my trainer

  1. an old 26 inch wheeled MTB with a trainer tyre
  2. my road bike with 700C

I would rather not use my road bike as I don’t want to wear my road tyre prematurely.

Although I don’t actually notice a huge difference in speed/power seen on Zwift but that’s probably because I am not that quick/consistent at the moment.

hmmm, in some highly un-scientific tests, I produce more power on my 700c 28mm Defy in Zwift than I do on my 26inch wheel Rockhopper with a trainer tyre on. Although there is not a lot in it.

I was expecting the MTB with its smaller wheel and skinny trainer tyre to fool Zwift and produce higher power.

Maybe its the geometry and ergonomics of the road bike that is making me more efficient compared to the road bike.

+1. Wife (650c road bike) wants to try Zwift and who knows one day even kids with 600c or 26" bikes will give it a go. I am sure there are lots of 650c and 26" wheels out there.

I use a Lemond RevMaster Pro to exercise and I mounted both the Minoura Speed & Cadence sensors on it. The Cadence works great, but the speed is off. 

I dialed in the speed on my Garmin Forerunner 920XT by manually entering the wheel circumference.  Can you please either add the ability to add wheel circumference in the Zwift setup or read the data from the Garmin?   Love the app but its not challenging when I zoom past everyone.