Phone cradle with Garmin Quarter turn mount

Making a custom mobile phone cradle with Garmin Quarter turn mount to use with the bike on the smart trainer at home

Garmin mount phone holder

I have been using Zwift with my first generation Wahoo Kickr bike trainer for several months now, firstly due to bad weather over the winter months and now due to the current Covid19 lockdown in the United Kingdom.

I run the Zwift software on my desktop computer via an ANT+ dongle and have been using my iPhone to control the software when cycling but I have always had the phone on a nearby table or chair which isn’t very easy to use.

I wanted to be able to mount the phone into my existing Garmin bike computer mount using the quarter turn locking system which all Garmin computers use but I couldn’t find anyone who made a suitable conversion bracket.

KOM Cycling make a product called “KOM Cycling Garmin Edge Universal Phone Adapter” which is a small plastic mount which goes into the Garmin quarter turn mount and fixes to your mobile phone with a 3M adhesive pad. Amazon UK link:

Garmin mount

As I don’t want to keep the mount fitted to my phone all the time, making a phone holder which then has the KOM mount fitted seemed to be the best solution.

Cutting on the mill

We had an offcut of 10mm thick clear acrylic in the workshop and Andrew designed a cradle for the phone in Autodesk Fusion 360 and this generated the G-Code for our CNC mill to cut the acrylic sheet.

The cut holder

The phone cradle is designed for an Apple iPhone 10x and iPhone 11 pro with the phones in the official Apple rubber or leather case. The design can be modified to fit other phones and can be 3D printed if you do not have access to a milling machine.

The design files can be downloaded in a ZIP archive which contains the following formats: .iges, .step and .stl files.

Once the acrylic sheet had been milled, we sanded the edges to remove any sharp corners and fitted the Garmin mount adapter using the supplied 3M adhesive pad.

Phone holder on the bike

The phone fits into the cradle and seems to be very stable and doesn’t move around when using the bike on the trainer.

On the bike

Please note: This phone holder is not designed to be used on your bike on or off road outdoors as it does not have any clamping system to hold the phone in place.



04 September 2020 at 2:40 pm
Instead of creating the phone case yourself, I suppose it is also possible to attach the KOM adapter to any kind of phone case that is available for purchase in a store/online. ..?
30 September 2021 at 4:03 pm
Man, this is what I've been searching for online. I want to clip my phone into my Garmin mount without permanently attaching something to it. Ideally something I can just clip my phone into for Zwifting. How does this not exist??? You should manufacture and sell these!

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