4iiii connection issues

I’ve got two 4iiii single sided crank power meters and I’ve had connection issues with both. I’m struggling to get either to connect to my phone and their app to calibrate them. After a lot of turning things on and off I’ve had both connected at various points but never at the same time and currently neither will connect.

It connects fine to Sufferfest and to my Element.

I’ve tried asking their support but despite giving lots of details all I got back was a generic doc that didn’t help.

Just wondering if anyone else has one and has any problems or any tips on getting it working.

The phone is a Pixel 3a.

I’ve got two and have had similar problems with their iPhone app, it seemed to get confused that I had two but with the most recent app update I’ve managed to delete them both and reconnect them and works fine at the moment. Pretty sure my GPS was always able to connect and calibrate them though

What GPS did you use to calibrate them? That was going to be my next question to their support, is there an alternative for calibration?

I’ve got a lezyne super gps and a lezyne micro

I’ve just had a look and my Element also has the same option, I didn’t know about that.

Going to give it a try and if it works I don’t need the phone app as that is all I was using it for.

Might just have to keep an eye on the firmware updates but they don’t really matter most of the time.

Hi… I have the same problem with the 4iiii PM.

The only fix for me is turning (Android) phone off and on again, it connects to calibrate the PM then.

It is never a great connection though. Not sure if the problem lies with the PM or phone, but a restart of the phone seems to sort it.

Also, not sure how important it is to calibrate everytime, as doing a session without calibration has made no discernible difference.


Unreliable describes what I’ve seen as well. My phone was connected the other night but refused to reconnect when I tried today.

Suf has had no problem talking to it but I gave the zwift trial a go it rarely named to pick it up and when it did it randomly dropped out quite a few times during a ride.

I’ll give a phone reboot a try.

Don’t know about calibration, some people say it should be done before every ride as the measurements are temperature and condition dependant, others say they do one once a month.

I listened to a podcast with a guy from 4iiii and he very much downplayed the importance of calibration/zero offfset

That’s good to know. I’d still like to know why their own app has trouble pairing with the device even though others can pair without problems.

I had a similar issue when setting up my new 4iiii PM. The old one worked totally fine, but the new one is having some issues connecting to my phone via bluetooth. Had zero issues connecting to my Kickr, so I figure it might be an ANT+ vs BT issue.

I’ll have to do some more digging but honestly, it’s a non issue for me since I’m new using just my phone for this. Definitely weird because the other one was totally fine, as was the specialized power crank i have that’s based on 4iiii tech.

It’s not because your kickr is automatically taking the Bluetooth connection?

Which connection? In my setup, I’ve not told the kickr about the crank so the two shouldn’t be connecting.

In general, I’ve found that the 4iiii and Stages crank based PM’s just do a better job connecting over ANT+. I have 2x 4iiii units, one specialized power crank unit, and used to have a 2nd gen stages unit. I’ve found that the specialized unit is by far the most stable/reliable over bluetooth. I haven’t had any dropouts with any of them with ANT+ when riding the trainer, but its definitely something I’ve noticed when trying to use the wahoo app on my phone to see how the power meter is reading in reference to my Kickr!

Do you have the wahoo app paired with the 4iiii?

No, why? I don’t think I’ve ever paired them.

Everything did seem to work better today when I paired to zwift using the companion app on my phone.

It was just the way I read the last sentence, sounded like you might have paired the two.

I’m pretty sure the Bluetooth signal can be read by multiple devices/programs at once.

I usually use ant+ for one and bt for the other. I’ve been having issues with the 4iiii and bt connection but it worked great with zwift companion so that’s what I’ll likely keep doing!

Most BT will work with multiple but some won’t, don’t know about this one.

Phones don’t have ANT+ so that will be using BT. My 4iiii talks fine to some apps but not others. Will talk to SUF over ANT+ on my PC but not Zwift.

I’ve got a 4iiii single sided and agree that it can sometimes be finicky connecting over Bluetooth. When I calibrate it I always calibrate with my Garmin Edge 520 and rarely had a problem. Until I did. That is, calibration was failing no matter what I did. Mind you this was after a couple of years of solid and reliable performance. Turns out the unit had gone wonky and needed to be repaired/replaced and support had me send them the crank back (Praxis Road Zayante). Since then, all has been good with calibrating again, always via the Garmin head unit. I share this because my experience with their Support has really been exceptional whenever I needed them.

@digininja, I wouldn’t dump the 4iiii app since it is needed in case there are any firmware updates. I know you said it doesn’t matter most of the time, but, and it might just be me but I am obsessed with ensuring all my bits and bobs have the latests tech updates installed. Last thing, and sorry of this is too obvious or you’ve tried already, but have you replaced the battery? It’s something I forget to do sometimes in my obsessions to get everything else connected and up and running.

Hypothetically, BT protocol supports multipoint connections starting from version 4.0.

But so far it barely works reliably with most devices, and I’m not sure if this feature applies to anything other than the headphones connection profile. To be on the safe side, as I know, it is generally recommended to ensure a point-to-point connection for PM devices.