Last week Zwift began rolling out updated firmware to Zwift Hub owners. The big feature of the latest firmware (version 4.0.1) is auto calibration, and that’s big news since the only auto-calibrating trainers on the market are the premium-priced Tacx Neo 2T, Wahoo KICKR, and Elite Justo!
How Auto Calibration Works on the Zwift Hub
Once you’ve updated to firmware version 4.0.1, your Zwift Hub will automatically calibrate throughout your ride whenever you coast for at least 5 seconds from a speed of at least 15kph/10mph. Essentially, auto calibration is the same as a manual spindown calibration… it just happens automatically every time you coast.
So whenever you supertuck down a hill, or hop off your bike to hit the loo between your warmup and race, the Zwift Hub will calibrate itself, optimizing power readings automagically.
Note: since calibration is sensitive to internal temperatures, auto calibration will not occur until you’ve ridden for at least 1 minute and gotten the internals of your trainer warmed up a bit. Additionally, auto calibration will not occur while you’re in ERG mode.
Installing the Firmware Update
One Zwift Hub advantage is its direct integration with the Companion app. Updating the Hub’s firmware is easy within Companion! Make sure you don’t have Zwift running with the Hub already connected. Then just go to “Zwift Hardware” under your “More” menu in Companion and walk through the steps:
The update took ~2 minutes to install.
Does it work?
Yes. I’ve ridden on firmware version 4.0 and now 4.0.1 for several weeks, and everything seems to be working well. It just works.
For example, in this Zwift Fondo ride I took a short break at two different times, hoping to trigger an auto calibration. If you compare the power numbers before and after the first break, the Hub’s numbers are measurably closer to the Assioma pedals. I assume this is due to auto calibration occurring (although there are no messages which pop up or logs I’ve found stating that an auto calibration occurred).
In the end, I’m of the opinion that auto calibration is always a good thing. It’s too easy to neglect manual calibration, and it’s even possible to cheat manual spindowns on some trainers. Auto calibration makes those cheats harder to pull off, requires no work on the user’s side, and ensures a trainer is as accurate as its hardware allows.
Don’t just take my word for it, though. Listen to the Lama:
Rollout Schedule
Firmware version 4.0.1 is available if you are already using v4.0.0.
For everyone else on older versions, Zwift began rolling out 4.0.1 to the first cohort (10% of Zwift Hub owners) on Monday, March 27. Their goal is to complete the rollout at the latest during the week of April 10th, so if you don’t get an alert on your Companion app, just be patient – your time will come!
More to Come
In chatting with Zwift’s hardware team, there are clearly more improvements to come in terms of Hub+Zwift game integration. Watch for more updates in the next few months!
Questions or Comments?
Post below!
Will these features also roll out to JetBlack trainers (as the Zwift Hub is a rebranded version I believe)
That’s up to JetBlack. Zwift engineers work with JetBlack’s on some firmware features, but the firmware was “forked” some time ago so they’re totally separate.
I believe JetBlack released autocalibration months ago…
I would very much like to see Zwift roll out some sort of validation process for Zwifters competing in the races to justify the numbers and w/kg that they are producing. Ideally all racers should be riding with the smart trainer as the power source but many ride with the PM as the source because it reads higher (then even post duals that clearly show this). Variations between power meter readings can be huge, especially if the output is manipulated (ie using wrong crank length). I had an old second Gen Stages that was often close to reading 10% more… Read more »
I left ZRL for that reason. It was just absurd what power numbers were needed even in the lowest division. On my Quarq I had a 20 minute power of 5 W/kg but on my kickr I got dropped like a bag of potatoes on every climb in ZRL.
Totally agree Roger, we are seeing this more and more riders putting out crazy numbers 10wkg for 1min and nearly 6wkg for 20mins. Riders using power meters as primary source, that are obviously being manipulated to over read needs to be stopped! This needs to be addressed and having a conversation about it has to be a starting point. How can we, as race organisers put on fair races, when you see all sorts of numbers. We can request a dual record but then what? Who can we report these “special talented riders” too? It feels Zwift doesn’t want to… Read more »
WTRL won’t remove obvious cheaters either. Sad.
Within my club, we are firm believers of clean and fair racing. We are starting a process to get all A+ riders and those with a race ranking of below 125 to show IRL data for efforts of 15s/1m/5m and 20m with a HRM and Powermeter. I appreciate that not everyone has a 20m safe stretch of road but everyone should at least be able to find a small safe hill climb to do a 5m effort. The power meter reading can be corroborated using weight and speed metrics, (there are a few websites to do this) so it gives… Read more »
I don’t race, but when I started riding Zwift with a new Zwift Hub, my watts started really improving a lot, to the point where I was suspicious of my “improvement.” At that point, I didn’t even know I was supposed to calibrate the Hub regularly. Eventually, I figured it out and calibrated and my watts went way back down. But I’d guess there are people out there who race and would just take advantage of that situation.
I just went to updat my zwift hub but even though the companion app shows I have firmware 3.9, it says I’m up to date. Is there something need to do in order to get the update?
From above…
Rollout Schedule
Firmware version 4.0.1 is available if you are already using v4.0.0.
For everyone else on older versions, Zwift began rolling out 4.0.1 to the first cohort (10% of Zwift Hub owners) on Monday, March 27. Their goal is to complete the rollout at the latest during the week of April 10th, so if you don’t get an alert on your Companion app, just be patient – your time will come!
I’m french.
The companion application displays that I have firmware 3.9, and that I have the latest version available.
However, versions 4.00 and 4.01 are available.
How can I get these updates please ?
From above…
Rollout Schedule
Firmware version 4.0.1 is available if you are already using v4.0.0.
For everyone else on older versions, Zwift began rolling out 4.0.1 to the first cohort (10% of Zwift Hub owners) on Monday, March 27. Their goal is to complete the rollout at the latest during the week of April 10th, so if you don’t get an alert on your Companion app, just be patient – your time will come!
I just tried to update the Zwift Hub firmware (4.0.1). During the update process, my phone screen went off though. After that the ZC app told me the update failed but my phone still showed me the ongoing update process. Once finished, the ZC app now tells me that I’m on the latest version. When I start the Zwift App, my computer can’t get a Bluetooth connection to the Zwift Hub though (no other Bluetooth devices in the area, not connected with the ZC app anymore). Maybe I have to undo the latest firmware update and try it once again… Read more »
a few months ago I bought a Sterzo Smart but I’m unable to make a connection to it. I do get the message “A firmware update is required for the latest version of Zwift to fully communicate with the hardware named STERZO”.
Any ideas to get this working?
Update the firmware! 😃