BT dropouts - FTMS resends

Okay…anyone feeling nice enough to help me finally get to the bottom of my signal dropouts? :slight_smile: I’ll buy you a coffee stop…

  • Win 10
  • Saris H3
  • BT connection
  • Have used both laptop’s BT and a dongle about 1.5 feet from the H3–dropouts with both
  • BT HR strap
  • BT headphones connected to Android phone at front of bike (headphones on head)
  • Mesh Wifi, router 2 feet away
  • Happens independent of my wife and her setup riding next to me or not
  • Would be a pain to use ANT+, hoping to solve the BT problem instead

I’ll get 1-3 dropouts per ride (most often 1 when it happens), but not every ride. No real pattern, sometimes weeks without any, sometimes in back-to-back rides. The cutouts are sporadic enough that it’s very difficult to trial-and-error through fixing the issue, because I’ll try something new and they might not happen for a week, two days, one ride…but they might not happen for a week, two days, one ride anyway.

Ran my latest log through Zwiftalyzer, it told me that I had 27 BT FTMS Message Resends, 3 BT Trainer Resets, and 1 BT Disconnect. The resends don’t lead to a reset unless there’s a bunch of them, and even then it’s only the Disconnect that’s the functional problem when riding.

In that Log, I’m getting a number of

[18:18:27] [FTMS] Resending last request.
[18:18:25] BLE : Protocol error on write -671091976

then a couple of these

[18:18:33] [FTMS] Request took too long, resetting trainer.
[18:18:33] [FTMS] Updated state from 7 to 1 and opcode from 17 to 127
[18:18:33] [FTMS] Updated state from 1 to 4 and opcode from 127 to 0
[18:18:34] BLE : Protocol error on write -671091976

and then a long list of these

[18:18:57] BLE : Sending DEVICE - DATA LOSS [ Name: Power|Cadence|Controllable UUID: 273177005830440 ]

then another reset, and then finally

[18:19:19] BLE : Sending DEVICE - BLE RECONNECT [ UUID: 273177005830440 ] Toms H3

All that over about 10 seconds, and that’s the bunch I was in off down the road :cry:

I have a couple of Windows Event Logs from past dropouts, but I don’t entirely know what to look for in those.

So…if anyone wants to help, feel free to walk me through things from the start if you want. I’ve done a bunch of things over the months already, but honestly I’m at the point where I think it might be best to not assume I’ve checked things properly and to start at 0.

Here’s this:

I feel your pain and as it doesn’t happen every time i’m guessing the testing process can take a long time!
Have you tried connecting via the companion app to rule out device issues? Does everything drop out or just the trainer/heart rate one at a time?

I used to have a weird issue where bluetooth would briefly drop when i started a playlist on my phone, only happened with playlists and phone wasn’t used for anything connected to zwift - was very odd but happened everytime - this doesn’t happen any more though. I also used to have drop outs when i woke up my bluetooth keyboard that had gone to sleep - again I don’t get this anymore.

If i was you (and you may have already tried this) i would hardwire your PC to the router, use wired keyboard/mouse, turn off bluetooth on your phone (wired headphones for a bit!) and not use a HR strap. see if you still have issues, if not introduce one thing at a time to see if one thing does it.

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I’ve just had this too.


Some useful tips here….

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What version of BT adapter is it. I’ve experience where the different supposed revisions cause issue.

Ordinarily the cheap generic ones are fine but on more than one occasion I’ve had to solve an issue by defaulting to a specific brand/version which kills all dropouts.

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update bluetooth drivers?

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I’ve tried going through Comp App in the past, but power response is laggy, so iirc I went back to going through the PC pretty quickly. I don’t think I had dropouts when I did that, though. Good call, I can try that again.

Also good question about the HR–I hadn’t thought of that before (wasn’t a concern as the bunch was racing off down the road ahead of me), but the entire data window up in the top left goes dark when this happens. So it’s a total BT drop, it seems, not just the trainer.

I use this laptop for lots of stuff–watching movies, online teaching, etc. No BT disconnects that I’ve ever noticed any other time. Grrr.

The luddite approach! :smiley: I could just shut off my mouse when I’m not using it. My previous BT mouse I would do that with, and when I powered it back on at any point during the ride, there would be a freeze/hiccup of maybe a second in video. But I could leave it off, go HR free, crappy wired phones, yeah. Worth a shot. The problem always is ‘how long do I have to do that’. If I do it and don’t get a dropout for a week…that’s not unusual anyway. But worth a shot.

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Windows told me last night before I posted this that my BT drivers were up to date (although…when it’s a driver dated 2006, I always wonder). The dongle is nothing special or brand new, don’t recall the specs.

yeah - i wasn’t suggesting any of that would be fun or what anyone might “want” to do!

if it is all connections in game it suggests something is momentarily tripping the bluetooth on your computer so maybe try eliminating non-game devices to see if that helps.

there is an app I use called remote mouse - there is a free version - that turns your phone into a wireless mouse (works over wifi) so could try that to eliminate rouge bluetooth sources. it has a keyboard too. It works fine for just navigating the game.

do you disable the internal bluetooth driver when using the dongle? Just to make sure it uses the dongle for bluetooth.

Ah, no, I don’t disable the internal driver. Need to look into that.

I do shut down most everything else running on the computer that I can (Adobe and MS launchers, that sort of thing).

if you go to device manager and disable the internal bluetooth radio then it will force it to use the dongle.

i usually disable it before plugging the dongle in to make sure i disable the correct one!


I’m thinking one of the first (new first, starting now, lol) steps I’ll take is picking up a new BT dongle. Thinking back into the mists of time, I think the one I have might be…well, old.

Do you think I should prioritize looking for BT 5.0, or something long range, or both? The trainer is only 2-3’ from the laptop. I could also stick the adaptor on the end of a USB cable, but I’m not up on whether that will degrade the signal or not.

Something like this ASUS:

Or something that’s an ‘All Caps’ brand, but has some good (non-amazon) reviews and is ‘long range’:

my laptop in on a cabinet just in front of my bike (about 30 cm from the handlebars) i have the dongle in the usb port nearest the bike (no extension cable) and works fine for me.

I have had most luck with pretty cheap BT 4.0 dongles - unbranded ones from amazon. I tried a few cheapish BT 5 with no joy - but can’t say if that is still the case. The one i have now works and i’m cool with that! If it ain’t broke…

this is the one i have been using for a few years and seems to work with my set up

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That’s where i was going with the BT adapter issue.

I’d stick with a good old fashioned rev4.0 as per the above suggestion. I prefer the TP Link ones but not sure of their availability your way. In every BT dropout scenario I’ve been involved in that’s sorted the issue.

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Okay, so begins the testing :slight_smile:

N=1 with the new BT dongle.
Strange results. Zwiftalyzer says 24 Resends, 0 Resets, 9 Disconnects…but I had zero in-game dropouts. Consistent power/HR connection throughout.

So one take from that is that it might be the Resets, not the Disconnects, that are the problem. So strange results, but a so-far-so-good from the experience.


i’ll keep my fingers crossed for you!

There’s only 1 person i can think of top offer advice on resets, dropouts etc…
R, Tom isn’t using QZ but do you have time to advice him about his issue?

What do resends, disconnects and resets mean?

I’m following this in case you need advice

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Did you review the advice in the Mike Hanney video? The reason to put the USB dongle on an extension is to get it away from the WiFi transmitter in the laptop. It will not degrade the signal.

Have you reviewed the WiFi configuration in the router and put it on a suitable channel? Shut off any 2.4GHz WiFi devices in the environment? Split the 2.4GHz and 5GHz bands into two separate networks so you can force devices to use 5GHz? Tried switching to a wired Ethernet connection to the laptop?

Why do you say it would be a pain to use ANT+? It sounds like you are already well into the pain.