Guess I don’t understand the focus on the word “promises.” According to DCRainmaker July 2021 review of the JetBlack Volt it had good accuracy:
"Overall, I’m pretty darn happy with accuracy here. While there were some early firmware reports of very small amounts of drift, I don’t see that at all on current firmware, or during any of my testing. Accuracy appears to easily be greater than the claimed +/- 2.5% figure that the company has for their tech specs, and seems to be closer to the +/- 1% variants we see on many higher-end trainers.
As with any trainer, there are some minor quibbles that I discussed above. But I can find those same quirks on a Tacx NEO 2T or a Wahoo KICKR 2020, and don’t even get me started on the $2,500-$3,200+ smart bikes that have worse accuracy quirks. So for $850USD all-in, accuracy is really strong here."
A firmware update changed that, as the latest Zwift Hub hands on said this:
“Then, just a few hours ago (yes, today), they sent over an e-mail confirming they found two items that contributed to the accuracy issues I and others were seeing on recent firmware, and believe they have them fixed for the next firmware update. That firmware version isn’t yet available to me, but likely will be within the next few days. Once I get that, and go back and put it through its paces over the course of a number of rides, I’ll circle back with a full in-depth review.”
Having worked in the embedded software industry for 30 years, have seen over and over and over and over again that regressions can slip into releases. And then they get fixed.
Power accuracy was working well in 2021, so I guess the promise is they are going to fix it? Why wouldn’t they? Are they lazy and want bad reviews? 