Charge 6 HR to Nordictrack VR21

[AdrianUK]

I can't get my 6 to broadcast HR to my VR21 bike. When I press the connection button on the bike it displays a pairing code but I can't see anyway to enter that on the 6. The HR broadcast on the 6 is just a toggle.

Is my bike too old to work with the 6 or am I doing something wrong?

[Triletics]

@AdrianUK it's more like the implementation of broadcasting is not exactly up to standards. It connects only to a very few devices which support BLE encryption handshake (and probably 99% don't support that because then all other HR monitors like chest straps and other sensors would stop working). I haven't managed to get broadcasting working with any gym equipment or my bike computers.

[AdrianUK]

The documentation said it had been tested with Nordictrack machines so I was expecting it to work seamlessly. It's not a deal breaker for me but just seems odd that they explicitly says it works with that brand hence why I'm wondering if I'm missing a step somewhere.

[Triletics]

It also says it has been tested with Concept2 rowers and didn't work for me. Unfortunately, Fitbit didn't specify actual models. Giving just a name of brand isn't particularly useful when there are tens or hundreds of models of the equipment.

[LZeeW]

@AdrianUK   The Exercise and Heart Health chapter of the Charge 6 manual says the equipment must support Bluetooth Heart Rate Profile and mentions "latest" models.  I think the fact that your bike displays a pairing code means that its too old to connect.  Is there a Nordictrack Support site that can answer your question?

[Triletics]

@LZeeW Nordictrack won't be a help here because they do everything as they should. If you take any chest strap, or HRM arm band or any watch that broadcasts it will just work. I'm not sure if you ever tried to use HRM with any gym equipment but the process is very simple. You stand on machine, machine finds the HRM, you connect and done. No other interaction is needed (and it's even simpler for ANT+ sensors because you don't need to pair at all). It works very same way for watches that can broadcast HR. The reason for that is that the machines expect users most likely to be using HRMs than broadcasted HR from the watch and external HRMs have no buttons or displays, no interaction during pairing is possible and they don't implement encryption. Fitbit saying that you need "latest" model is a very lazy statement because the latest model never guarantees support this kind of handshake for BLE device. This is uncommon thing for this kind of connectivity. It usually works when the heart of the machine electronics is Android (pretty much embedded tablet display) but for other solutions that most likely won't work. The problem is Fitbit implementation of broadcasting that prevents 99% of machines that can connect to external HRM over BLE from connecting. Unless Fitbit modifies implementation and follows market standards this feature will be a nice buzzword but rather dead on arrival for majority of users.

[AdrianUK]

They told me to ask here...

I expect it is because it's an older model as I suspected. No biggie, it was a nice to have rather than a must. I'm very happy with my 6 overall.

[mikey_pdx]

I have a NordicTrack s15i and it will "see" the Charge 6 once I turn on "HR ON EQUIPMENT" in the quick settings on the Charge 6. I tap "Connect" on the bike's screen and it says "connecting...", but it never connects. Bike firmware is up to date, as is the Charge 6. 

[v2.0]

I have the exact same issue as mikey_pdx's on my Nordictrack 2450 treadmill. Spent 2 hours trying to connect but it never did. 

[N8teGee]

Yes as @Triletics says, this seems to be a poor implementation on Fitbit's part.

Why they couldn't have just gone with ANT+ and allowed for broadcast and receiving is just another half baked solution. 

[Triletics]

@N8teGee it's even worse than I thought. Yesterday, pushed by one of the posts in the forum, I gave a go to Zwift running on my Android mobile. I expected the broadcasting to work the same as it did when I paired Charge 6 with the Strava app but apparently this is app-dependent. So my assumption (after testing with Strava) that it will pair with a mobile phone is wrong. It will pair with some apps, but won't with others. Here's the Zwift issue:

Got it eventually working with Rouvy but there is a bit of a problem when I want to reconnect it a second time. Rouvy does what bike computers do and shows "Connected" instantly even if I'm not broadcasting HR. So unpairing from BT is the only way to get it working again.

I tried to see whether I could pair it with Zwift Hub One directly (this smart trainer can connect to HR sensors directly) but no go (not a surprise).

[mikey_pdx]

I actually got it to work today!

After the failure earlier this week, I thought maybe having my phone's Bluetooth on (and thus the Charge 6 connected to it) might be causing trouble. So, I turned BT off on the phone and gave it a shot. First attempt at connection failed (no error, just went from "connecting..." to "connect" on the bike screen just as before), but it connected immediately the second time I tapped 'connect' on the bike's screen. Hooray!

The connection dropped about 27 minutes into my ride, but I was able to reconnect it via the bike's screen quickly and easily. Once I stopped riding, I stopped the recording on the Charge 6 and it disconnected from the bike automatically.

Only thing that was kinda dumb is that it recorded the exercise in the app as simply a "Workout", so I guess maybe there's no logic to determine that I was connected to a bike (maybe device info is limited to the BT connection type and OS?) and automatically categorize it as "Spinning" or whatever. Easy enough to just re-categorize it in the app, though.

I turned my phone's BT back on with a few minutes left in the ride (after the disconnect/reconnect event I mentioned earlier), and it stayed connected, so I'm not entirely sure if having the Charge 6 connected to the phone was the problem the other day or not. Entirely possible it was more related to having rebooted my phone earlier this morning, so I might give it a go with the phone BT turned on next ride.

[Triletics]

@mikey_pdx for me it didn't work. Might be different hardware. If you establish connection swipe up to change type of workout:

You should be able to change it to Spinning (there is only subset of all workouts available).

[mikey_pdx]

@Triletics I always forget about swiping up on the start screen. 🤦‍:male_sign: I'll try it next time. 

[Triletics]

@mikey_pdx this part of implementation is also weird. All watches I used so far did broadcasting in the background. So you could start broadcasting and then do usual stuff with the watch (and start tracking any workout). Fitbit usually implements everything "up-side-down".

[v2.0]

@mikey_pdx mine also finally connected yesterday! I did not do anything different from when I tried and failed for 2 hours the prior days. It just worked for some reason. Was excited to connect today but it took me a few tries today before it connected. So no clue yet why it's very inconsistent.

And it is annoying that it defaults to "Workout" exercise type. You need to change the exercise type once it connects, before starting the workout. 

[mikey_pdx]

And now this has stopped working. The bike "sees" the Charge 6 once I turn on HR On Equipment, and it *says* it's connected to the C6, but no indication on the C6 that it's broadcasting. I've tried starting an exercise on the C6 to see if that's how it's supposed to be done now, but it never starts broadcasting. 

Really a bummer, because this used to work consistently. I'd had probably a good 4-5 months or so of it connecting first time, every time.