Magsafe Trainer Mount for Garmin or Wahoo

About

This holds a magsafe-capable phone on a head unit handlebar mount (Garmin or Wahoo). A magsafe phone mount is sufficient to hold a phone on a bike while riding an indoor trainer vigorously.

The phone can be charged by the magsafe while mounted. The USB-C cable fits through a slot into the mount. It is sufficiently protected from dripping sweat as the connection is hidden inside the part.

Why

Having a phone accessible during the workout makes it easy to adjust the workout, change music, set "Do Not Disturb", etc.

I've used this setup to do workouts from my phone, connecting to my trainer's Bluetooth for power, cadence, and heart rate data for Trainer Road. It works great - especially for those endorphin workouts where I get creative ideas for other things - because I can just dictate them right onto my phone for reference after my workout.

Safety

This is for stationary use only - not for traveling with a magsafe phone! Don't trust a Magsafe interface to hold a phone securely while riding! Use it indoors only or for warmup on a trainer at your event. 

Related

2025-12-22 Update

Note about the USB-C port: it exists. I've have not yet plugged mine in because it's just one more wire to worry about. For me, it's sufficient that the magsafe holds the phone in place. My 2.5 year old phone battery will hold up for >>1 hour workout. YMMV.

2025-12-07 Update

This minor update adds a "split" model that simplifies the print. This improves:

• eliminates the need for supports from the split model

• allows easier visual alignment of the USB-C charging port in the hole

• provides a slightly larger USB-C hole, so a wider variety of cables will fit

Since the magsafe part is glued in place, and therefore you already have the hot glue out and warmed up, the split version can be glued together with the same glue.

I've also added parts for another magsafe vendor: THREEKEY.

If you are already using the part there's no need to re-print.

BOM

The part is sized to work with specific magsafe chargers. Choose one:

Gejin

USA: https://www.amazon.com/dp/B0DLP157QH

Germany: https://www.amazon.de/dp/B0F62TLP7M

THREEKEY Qi2

USA: https://www.amazon.com/dp/B0DHXNRQV5

Germany: https://www.amazon.de/dp/B0DHXNRQV5

Printing Notes

Print in PETG or ASA, as their flexibility make them more durable for something that should have some “give.” I found that PETG sticks to the print bed very well.

If you use PLA, you'll likely need to add a brim to keep the part on the bed for the duration of the print.

The Garmin mount must be oriented at 45 deg for printing so it has enough strength. The small flat area on the bottom edge of the part is designed to be placed on the print bed, with supports carefully located higher on the part. While making prototypes, this orientation produced the best outcome.

The "split" file was created so that supports could be eliminated. The split part prints faster, but you have to glue it together.

Assembly

Hot-glue the magsafe device into the part. Orientation should be self-evident to align the USB-C port with the tunnel. It doesn't require a lot of glue - just three pea-sized portions.

If you are assembling the split version:

1. glue the magsafe charger in the part, keeping the USB-C port aligned visually

2. glue the "mount" section into the "forked" section, with the mount pointing downwards

3. optional: plug your USB-C cable into the charger

Hot glue works well, but superglue should be fine as well.

Wahoo Compatibility

A Wahoo-oriented version is included, in which the mount is rotated 90 degrees from the Garmin version. This is untested, as no Wahoo devices were available.

One problem with the Wahoo version is that the mount will need supports, at least on the bottom edge. It may be difficult to get the same orientation as used for the Garmin. Let me know if it works for you.

Design

It's designed using OpenSCAD, and VS Code with a little Python.

Adds a magsafe mount that will hold a phone securely enough while riding an indoor trainer.