Hi All,
Please bear with me as this is a bit of a long post but completely relevant to this thread…
I’m really glad that I found this thread as I just started on Zwift a month ago. I’m not a cyclist (at all), and I’m using a Bowflex C6 and having tons of fun paired with Zwift. I have Crohn’s Disease and only Zwift 2-3 times a week for cardio as I don’t need to be burning tons of calories. I’m in really great shape otherwise, but was a little surprised by how well I was doing on Zwift. However, I didn’t think much of it as I’m not in it to compete with others, I usually just ride by myself and pedal as hard as I can for an hour, until I did one of the Tour de France Discovery Stage group rides the other day…
I had registered for the A group using the metric that Zwift had given me for my w/kg, not knowing that this was severely skewed where it’s just a virtual number they calculate. At the beginning of the ride a couple of others that were in the group started talking about zpower and people cheating using trainers. I wasn’t sure but had a bit of feeling that they might have been referring to me as I was out front so I politely asked who they were talking about and what was zpower. Another person in the group politely replied and said to google it and I asked a legit question on my behalf: “If I’m using a Bowflex C6 and my w/kg is anywhere between 5-6w/kg, is that not an accurate assessment of my power rating?” The guy replied that it wasn’t unless I was an elite athlete. As I said, I’m in really good shape, but definitely not an elite athlete, hahaha.
I think this is a bit of a problem for a couple of reasons, the first being that it seems to generate a bit of angst among some “real” cyclists who feel like they’re being cheated by people using spin bikes/trainers that over-exaggerate power ratings - I’m sure there are others in the same boat as me and have no idea that this is the case, and that the power rating that Zwift gives you using the C6/IC4 is only a virtual number. The virtual power rating given to me by Zwift is so far off what the actual number seems to be is a little crazy. Thanks to Matt Larson for posting the image with the calibration process. The C6 connected with Zwift so easily when I did my first ride that I had no idea anything was off in terms of power rating and other metrics. I followed the calibration process that Matt posted and I think it worked as my average w/kg is now anywhere from 2-3.5 w/kg when riding. I’m still passing some people, but I’m not winning any jerseys anymore, lol.
This doesn’t seem to be an issue with Zwift at all. I’m no expert, but is it not possible for Schwinn or Bowflex to have the computer properly calibrated when it leaves the factory so it’s set up properly for use by consumers to give a sane measurement of power, speed, etc? If the bike is not calibrated properly then it makes sense that Zwift will give you an insanely high power rating and all other metrics will be off. If it is calibrated properly then the power rating seems to be more realistic. As I said, I’m not a cyclist and have no idea about power ratings and what not, and obviously using a power meter is the best way to get a true number. Maybe Zwift or Bowflex could give people a heads up that this is the case and avoid some of these issues. I didn’t read anywhere in the Bowflex manual about calibrating the C6 after assembling it, and in reading some of the info about “your first ride on Zwift” I did not see this issue come up at all.
One quick question about the calibration process: after I calibrated the the C6 I found that cranking the resistance up to level 20 was super hard, would that make sense? I had been setting the resistance between level 40-50 in most cases prior to calibrating, and it was nowhere near the resistance that I’m now getting, even at level 15. As someone else said above only being to calibrate the computer/bike 3 times does seem a little crazy, could this be fixed with a software update? If I did the calibration process incorrectly and had to do it again then I would be on what the computer says is the third calibration process. Any info on this would be greatly appreciated. Cheers!