Keiser M3i

Hi all. I have seen the Keiser M3i used to not support zwift in 2018. But I have seen people on other forms mention they use both together. Has the M Series Converter since resolved the issues they were having?


Have you had any luck on this front?

I have a Keiser M3i bundle (including the converter) arriving this week, and plan to try and get Zwift up and running connecting the M3i on a Mac Book Pro and projecting onto a TV via HDMI. Any tips, tricks, or advice welcomed.

We have successfully been using the Keiser M3i on Zwift since October 2019. The biggest problem for me is that the resistance doesn’t go high enough. Level 24 is the brake. We’ve also had connection issues with the bluetooth converter as well as super fast battery drainage. Other than that it works quite well. Make sure you spin on the bike before trying to pair.

Hello - I was going to start a new thread, but see you are covering the M3i topic here. I have recently connected my M3i to a computer running the Zwift app via the Zwift companion app on a Samsung S10+.

My main issue is getting a heart rate monitor signal to the Zwift app. The M3i sends Power and Cadence via the companion, but does not send the Heart Rate which it shows on the M3i computer display.
Does anyone know if there is a pending Keiser bug fix for this? Or a solution to get the HR signal to my computer using non-Apple equipment? This is frustrating due to the fact that many of the events/races require a HRM signal. Thanks for your help!

I bought a newer HR strap which does communicate well.

Garmin HRM-Dual Heart Rate Monitor

Thanks Sebastiaan, I spoke with Kieser today and they are sending me another BT Converter due to my continued dropouts. I told them about the HRM problem and they say it’s the first time they have heard of this issue and will look into it and get back to me. I’ll update the forum with their reply. Heath

They are REALLY GOOD at sending replacements out! LOL. We received 3 handlebars because they were not straight and 2 BT connectors, also because of the dropouts. The replacement never worked, but the 1st one has been doing okay lately. Still dropouts though.

LOL, he was rather quick to offer a replacement BT converter. Let’s hope they can resolve our issues, how can I become a world Zwifting champion with these drop-outs :wink:

Update and reflections, for those searching in the future on this topic. Keiser M3i bundle purchased in December 2019.

What worked for me:


  • Download and run the Keiser updater for the M3i bluetooth converter. Update the converter firmware.
  • Register for Zwift, and install it on your computer. Run it the first time, log in, tell it to connect to devices using the companion App, and close it down.
  • Install Zwift Companion App on cell phone.

Every time I run Zwift:

  • Turn on heart rate monitor.
  • Get Zwift up and running on the computer (I’ve used both a MacBook Pro as well as a homemade Windows 10 PC), connected to a wireless network. Make sure you told Zwift to make connections on the Companion App instead of the computer’s bluetooth.
  • Get the Zwift Companion App up and running on the phone, with Bluetooth on and connected to the same wireless SSID as the computer running Zwift.
  • Pair heart rate monitor, cadence, and power. [after the first couple of times, mine got to where it just does this on its own each time].

It took a few passes to get things locked in, and the first pass, the Converter burned through the supplied battery really quickly. I had to re-install the firmware update, but that, along with a new lithium battery, seem to have things on track.

Things to note:

  • If you do power based workouts with short, high wattage intervals, they are hard to hit reliably and get your “star” for completing those interval segments.
  • My wife uses the Peloton app with the M3i, and it is serving double duty admirably.
  • The M3i is quiet, smooth, quickly adjustable, and just NICE. Riding with it on Zwift is infinitely better than being in a basement on rollers staring at a wall.

I’m coming back into cycling after a LONG time off. The day will come I get a new road bike and a Tacx 2T (or equivalent “smart” trainer). Given my wife wanted a bike for Peloton, and I wanted to get back in shape and try out Zwift, I’m happy with the M3i purchase. It did take some tweaking to get the connections to pair up reliably and without fiddling each time, but I appear to be there now, so it is doable.

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Great write-up Doug. I too enjoy riding the M3i, it’s very smooth, quiet, and consistent. I received a replacement M3i converter yesterday from Keiser and a Garmin HRM-Dual Heart Rate Monitor from Amazon (recommended above).

I updated the firmware on the new converter to the latest version and have completed (2) 1-hour + rides without any drop-outs to the companion App. What a relief…

I was still unable to get the HRM data to the Zwift app using the HRM strap that came with the bike. So, I put on the new Garmin HRM and it connected immediately to the companion App for both rides. This is a minor workaround, but at least I am fully connected now and stable.

I still have a ticket open with Keiser to resolve the HRM, so I’ll still report back on that.

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Any more updates regarding the Keiser M3I?
I am considering purchase. I know I like the bike, but would like to hear if there are any more issues regarding connectivity. Also, if the lack of controlled resistance is a major drawback.


I am in the same boat – Looking at this option because I too love this bike, but riding Zwift is most important to me – And I would love to avoid the Wahoo kickr bike but I will do it if it means avoiding dropped connections. Looking forward to others reports!

I received my brand new Keiser M3i the other day and have connected, using the M Series Converter, to an iPad Mini (which fits nicely in the holder). So far I am still getting used to the platform. I did lose connection once, then it came back on. If that had been during a race, it may have been more disappointing. I am using a Polar HR monitor, which connects to the Keizer computer automatically, but when connected to Zwift it reads a flat 98 bpm and never changes. So something is wrong there and I will research that issue.
The lack of controlled resistance isn’t too bad because I am used to the resistance settings on the Keiser bike already. You just need to think of it as terrain settings, not equivalent to gears on a bike, and focus on power output.
In general, for the real Zwift experience, a smart trainer and a road bike is likely far superior. We wanted the Keiser because we both want to use it without swapping out bikes. Also, we have it on our 3rd floor and didn’t want to haul bikes up and down.
However, if I could have found a Wahoo Kickr Bike readily available, I probably would have sprung for it.

I recently bought a Keiser M3i with the M Series Converter and Polar HR monitor. I am able to use Zwift and have been for the past month. Receives Cadence, Power and HR. Seems to work pretty well as long as you limit the number of bluetooth signals only to the one computer (I use MacBook Air hooked up to a monitor) that is operating the Zwift program. You can use the Companion Zwift app on another device (iPhone) as long as you use wifi (same wifi modem as computer) and disconnect Bluetooth. Simultaneous bluetooth signals cause your ride to stop intermittently during the ride which is frustrating.

Now that I’m over a month in I have also figured out a system that works well. I am using an iPad, with an iPhone running the companion app. Signal has dropped a couple times, but that might have been my wifi.
Make sure you update the Converter firmware using the M Series app. That will save battery power. Also, for me it works best to connect the Polar signal to the bike before opening the Zwift app on the iPad.
Thanks, and Enjoy!

Thanks. Updated converter for better battery.


I have an m3i and have been using Zwift for about 6 weeks and have never had a problem. Sometimes the HR drops out for a fraction of a second - I think that is a converter issue - but it’s not enough to mess up the stats for the ride. Do any of you race using the m3i? I’m curious if you have had any problems or issues with racing.

I’m enjoying the M3i, mostly group and free rides, some training and only a few races (D). Not a serious racer.
The bike computer started glitchy get out, giving me occasional 1 minute rests so it could shut down and reset. Tech support told me there might be a glob of grease in the sensor connector down at the flywheel. There was! Wiped it off, all fixed.

Working well for me as well. group rides and solo. Seems that whenever I update the Converter I either run out the battery or cause some connectivity problems. Dropped out for and electronic flat tire today but managed to catch up.


New user here, (new to biking too).

Just bought an M3i (arrives tomorrow), and was planning on purchasing the M3i converter also.
I’ve never used Zwift at all, but any gamification of riding will help me stick with it, so Zwift intrigues me.

I had hoped Zwift would run on an iPad and that’s all I would need, but I’ve seen some mention in this thread of two devices being used, a tablet and a computer?

Are two devices really needed?