BEStie

Your Bosch ebike already measures your power.
Let your fitness gear hear it.

BEStie is a tiny gadget that bridges your Bosch Smart System ebike and your smartwatch or cycling computer — streaming power, speed and cadence in real time to Garmin, Wahoo and other smart-trainer-compatible devices, with no power-meter pedals required.

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BEStie in action: the same power, speed and cadence values on the Bosch display, a Garmin Edge computer and a smartwatch

One ride, three screens, identical numbers: bike display, cycling computer and watch.

The problem

Bosch ebikes can measure rider power and cadence — everything you need to track your fitness progress without investing in expensive power-meter pedals or crank sensors (which are impossible to fit on most ebike cranks anyway).

In May 2026 Bosch enabled telemetry over Bluetooth — the Live Data Interface (LDI) — on bikes with Performance CX Gen 4/5 and Performance SX motors. But the way an LDI peer device must be built makes it hard to adopt in existing products: so far only a handful of Garmin Edge computers support it.

The solution: a translator

BEStie is free, open source firmware for cheap, widely available Bluetooth boards. It sits between your bike and your fitness gear and translates:

  • Towards the bike, BEStie is a fully spec-compliant LDI peer. Open the Bosch Flow app, tap “add component”, and a new bike display named BEStie appears. Connect. Done.
  • Towards your fitness gear, BEStie looks like a smart trainer (standard BLE FTMS indoor bike) that streams power, speed and cadence. If your device works with Zwift-compatible trainers, it just works with BEStie — add a sensor, go for a ride. That's it.

Afterwards every ride is seamless: power on your bike, start activity tracking on your fitness device, and the data is simply there.

Why BEStie?

Highly accurate data

No conversion tricks: power and cadence values match the Kiox display and Flow app recordings exactly.

Vendor agnostic

Smart-trainer support is everywhere in the Zwift era — Garmin Edge computers, Garmin watches, Wahoo ELEMNT and more. No waiting for your device maker to adopt Bosch LDI.

Months of battery life

60 µA in idle, 140 µA while riding — months on a coin cell, over a year on a 1000 mAh LiPo. Throw it in your saddle bag and forget about it for the whole season.

Two devices at once

Record on your watch while seeing live values and alerts on your head unit — BEStie connects to both simultaneously.

Seamless bike switching

One BEStie board pairs with up to 10 bikes. It just follows whichever one is turned on.

Free & open source

Runs on boards costing a few dollars. Lovingly handcrafted — no AI-generated code.

How it works

  1. Get a board & flash BEStie

    A ~$10 nRF52840 board and ten minutes with our web-based uploader. No soldering for the recommended setup.

  2. Pair with your bike

    In the Bosch Flow app: settings → components → add component. BEStie appears as a bike display.

  3. Add as smart trainer

    On your watch or cycling computer, add BEStie as a smart trainer sensor — like any Zwift trainer. Ride.

Check hardware compatibility

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