Zwift iOS, PowerCal, and a Spin Bike


(Bob Venturi) #1

We have a few spin bikes in our gym at work, and it was kinda of cool to be able to use them with Zwift this morning.

I have a BLE PowerCal which provided the Power and HR numbers to my iPhone 6 Plus running the Zwift iOS app.

The combination worked pretty well for a quick 40-minute ride at lunch on a rainy day.  It certainly beats mindlessly staring at the wall.

Although the PowerCal is pretty suspect accuracy wise, it really is nice that it along with your iPhone will allow you to use Zwift anywhere you have a gym/spin bike.


(G reenfritos(SVCG)) #2

I’ve wanted to try this during a spin class actually, zone out the annoying tiny 20-something instructor who keeps yelling “tap backs!!” even though I’ve yet to figure out where in my outdoor (or indoor cycling) tap backs will help me.  

I think at some point I may test my PowerCal vs. my pedal based PM.  What is your experience with using just the PowerCal?  On a bike outside, I’ve noticed the power readings via my Garmin head unit varies in the short term, but overall power averages seem to smooth out fine.  I’d think that fluctuation would cause your avatar to be jerky in the game.


(Bob Venturi) #3

No, it works fine. I think Zwift smooths the power somewhat over time also, so you don’t really notice any jerky movements.

It does take a little getting used to though … for instance if you take it easy and your HR starts dropping quickly, your power will drop to zero and you’ll start to coast, at that point I just start pushing it a bit and the power comes back up as my HR does.  I have been able to hang with group rides without much of an issue although drafting with the PowerCal as the power source takes a little practice.

Overall, at the end of the ride my power/speed numbers are almost identical to what I get with my Tacx Vortex Smart.  

I rode the spin bike today in our work gym with the PowerCal and Zwift and it worked fine.  

It’s nice to be able to use Zwift anywhere with any type of bike … only issue is that the experience is no where near as engaging looking at my 5.7" iPhone screen vs. my 50" TV … 45 minutes is about all I can take.