Converting a Garmin Vivoactive 4 to QuickFit

Eddie Zhang -

For the 5 other people in the world that may want to do this mod, I figured I'd write this quick blog to save you about 30 minutes of Googling/scouring Aliexpress. It should also work for other Garmin watches that aren't QuickFit compatible.

Background

I wanted to collect data during bicycle rides using my Garmin watch and pair it with ANT+ cadence and speed sensors. While you can do this out of the box, it can be hard/dangerous to look at your watch while riding so I needed a way to mount the watch onto my handlebars.

For the people thinking right now that I should just get a cheap cycle computer, I didn't want another device to charge, and another app to deal with.

Garmin officially sells 2 accessories to help you mount your watch to your handlebars.

  1. The "Bicycle Mount Kit" - https://www.garmin.com/en-AU/p/11078
  2. The "QuickFit Quarter-turn Bike Mount - https://www.garmin.com/en-AU/p/717689

The Problem

The normal mount kit is ugly so that wasn't an option.

The QuickFit adaptor + out front mount looks really sleek but my watch doesn't support QuickFit!

For the unaware, Garmin's higher end watches use QuickFit bands while the cheaper watches use Quick Release style bands where the bar is embedded in the band.

To adapt our Quick Release style watch to support QuickFit, we simply need to install a spring bar in place of the quick release band and purchase a QuickFit band for normal use as a watch.

QuickFit Conversion

Standard watch spring bars can be commonly found in these diameters: 1.5mm, 1.8mm, 2.0mm, 2.5mm.

This is the measurement we are talking about.

Meanwhile, Garmin's QuickFit spring bars are 2.3mm in diameter which appears to be a proprietary size (did they make it proprietary to prevent people from doing this mod?).

Option 1 - Use Undersized Spring Bars (2.0mm)

The 2.0mm diameter spring bars will work with QuickFit accessories but there may be some amount of play caused by that 0.3mm gap.

If you don't think this will bother you then this is the easiest and cheapest method to adapt your Garmin watch for QuickFit.

Option 2 - Watch Strap Tube + 1.8mm Spring Bars

You can find watch strap tubes which are intended to be used with leather watch straps. The ones I bought were ~2.3mm outer diameter and ~1.8mm inner diameter.

By combining these tubes with a 1.8mm spring bar we get this result:

From top to bottom in the photo:

  • Watch strap tube + 1.8mm spring bar installed on the watch.
  • Just the watch strap tube.
  • Watch strap tube + 1.8mm spring bar partially inserted into the tube.
  • Just the 1.8mm spring bar.
💡
Note: I bought tubes which had the same length as my spring bars (22mm). This makes removing the assembly without destroying them pretty difficult. If you want to be able to remove them easily consider downsizing the length of just the tube.

Option 3 - Try Hard Mode - Watch Strap Tube + 2.0mm Spring Bars

For the perfectionists, there's still a tiny bit of play caused by the gap between the 1.8mm spring bar and the watch strap tube.

Due to variances in manufacturing, I actually found it was possible to fit some of my 2.0mm spring bars (with a bit of sanding) into the watch strap tubes to remove this gap as well. Your mileage may vary with this option, I may have just gotten lucky with the batch I bought.

The Result

My watch supports QuickFit bands and can be mounted neatly on my bicycle now!

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