Karoo HR beta: Apple Watch heart rate on Karoo + complete rides in Apple Health

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Patrick Wills

• October 03, 2026 16:18

I’ve built Karoo HR for two things I wanted from my Karoo:

• Apple Watch heart rate on Karoo, displayed in its normal ride fields and recorded with the ride—without a chest strap or bridge device.
• Completed Karoo rides in Apple Health, including the GPS route, heart rate, distance, calories and available speed, cadence and power data.

The Watch connects directly to Karoo over Bluetooth. Transferring rides and saving them to Health doesn’t require internet. Your normal Karoo-to-Strava sync can stay enabled.

Karoo remains the ride recorder. If the Watch disconnects or runs out of battery, Karoo keeps recording; Watch heart-rate readings are missing until reconnection. Saved rides—including older rides—can be imported into Health later. If Karoo needs restarting, use Resume Ride if offered, then reconnect the Watch. I’ve tested that recovery during a real ride.

Watch battery use has been similar to recording a normal cycling workout in my testing. Plan on around two hours, depending on your Watch model and battery condition.

Recorded calories are used where available; otherwise, calories can be estimated when the ride contains sufficiently complete power data. The guide explains the estimates and Apple Health’s calorie-display limitations.

Try the beta

Tested on the 2024/third-generation Karoo. Install the Watch app through TestFlight and the Karoo extension through Hammerhead Companion—no computer or Developer Mode needed.

Installation guide, TestFlight link and Karoo download

Turn off Hammerhead’s separate Apple Health export before using ride imports, to avoid duplicates.

This is an independent beta project, unaffiliated with Apple, Hammerhead or SRAM. It’s provided without warranty and used at your own risk, including possible data loss or device problems. The full disclaimer is in the guide.

Feedback from other riders is welcome, especially on connection reliability and Apple Health imports.

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  Felipe Bruxel

  • October 31, 2026 04:18

  Hi, do you still have any spots for beta testing it? Sounds like a great app

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  Patrick Wills

  • October 31, 2026 10:24

  Yes it allows 100
  i think
  Used it yesterday for a 2 hour ride and only used a small amount of battery

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  Patrick Wills

  • October 31, 2026 10:30

  Yes slots still showing as available. Note that it only works for the newer Karoo 3. I don’t have the Karoo 2 working yet

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  Felipe Bruxel

  • October 31, 2026 10:34

  Thanks I managed to get it working! Haven’t ridden yet but have set it all up. I’ve been waiting to broadcast from the Apple Watch for years!! Main thing I miss from Garmin watches - hopefully not anymore!

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  Patrick Wills

  • October 31, 2026 10:40

  It has two functions and you don’t need to use both
  1. It lets you use the watch as the HR source. Then you need to connect them before the ride
  2. It lets you save any ride on the karoo to Apple Health with all the juicy ride data. So this can be done whenever but usually at the end of a ride

  I use both features- game changer!

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  Patrick Wills

  • October 31, 2026 10:42

  I now have the karoo set to sync to the usual things like Strava directly. This app handles the missing apple health piece

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