The product

A machined saddle, not a bolt-on accessory.

Every RAD 4 BMX starts from a polycarbonate pivotal saddle, machined under the seat to house the electronics and battery in a permanently fixed housing. The sensor doesn't come off, doesn't run flat without you knowing, and doesn't get lost in a bag.

RAD Signal
RAD 4 BMX connected saddle side view, RAD Signal sensor housing under the seat Underside of the saddle: RAD Signal sensor housing and pivotal mount RAD 4 BMX connected saddle, side view RAD Signal sensor housing mounted under the seat, close-up Underside of the connected saddle, RAD BMX plate and pivotal mount

What's inside

BasePivotal saddle, polycarbonate shell
SensorRAD Signal sensor — 25 Hz GNSS (GPS/Glonass/Galileo/Beidou), ground accuracy <10 cm
Motion±8G accelerometer, ±320°/s gyroscope
ConnectivityBluetooth 5.2, pairing with the RAD 4 BMX app, available on the App Store and Google Play
PowerRechargeable battery, USB-C charging
Battery life2h+ of continuous recording at 25 Hz
Mounting100% integrated — electronics and battery in a housing permanently fixed under the seat

What it measures

Speed & position

Full GPS trace of the moto, instantaneous speed point by point.

Acceleration

Corner exits, re-accelerations, jump landings — the real intensity of every phase.

Cornering angle

How far the bike leans in a turn, to measure the line you took rather than guess it.

The app

Your moto, exactly as you'll see it — not a mock-up.

A real screenshot of the RAD 4 BMX app, on the PH Sauze track of BMX Pernois in Pernes-les-Fontaines (Vaucluse, France): session summary, lap times and times at each point of the track, GPS trace — all compared automatically.

Download on the App Store Get it on Google Play Bluetooth pairing, live telemetry and statistics, on iPhone and Android.
RAD 4 BMX session summary on the BMX Pernois track: best time, consistency, theoretical optimum and lap-by-lap comparison

Best time, consistency and lap-by-lap comparison, calculated automatically over the session.

  • 📍 Full GPS trace of the track, corner by corner
  • ⏱️ Laps detected and compared automatically (Δ against the best time)
  • 📈 Speed and bike angle overlaid on the same chart
  • 📱 The same view on your phone, while you're still at the track
Mobile view of the RAD 4 BMX app: GPS trace of the lap, times at each point of the track and estimated mechanical power, at BMX Pernois
For riders

Preparation tools, not just numbers.

🗺️ My tracks

Set up your own tracks and place your virtual timing gates wherever you like — to target exactly the corner or section you want to work on, session after session, rather than putting up with an automatic split that doesn't match today's goal.

🔧 Toolbox

Gear ratio calculator and start-hill simulation to find the optimal gearing for your height, weight and level — the calculations a rider usually does in their head or on the back of an envelope, with real numbers behind them.

🚀 Start simulation

The official BMX gate cadence — lights and beeps, random delay before green — to practise gate starts in the same conditions as in a race.

Training

Timed sprints, without timing cells or a stopwatch.

You choose the number of sprints, the distance and the type of start — standing, like an official BMX gate (light and sound sequence, random delay before green), or rolling (the app arms the timer as soon as you reach the entry speed you've set). No more physical timing cells or counting out loud: the app places virtual timing gates along the whole sprint, so you can see your progress point by point — not just a total time at the finish.

  • 📍 Virtual timing gates placed automatically along the sprint, nothing to set up
  • 🚦 Standing start (BMX gate) or rolling start, your choice
  • 📏 Adjustable distance and number of sprints
  • ⭐ Every sprint automatically compared to the best of the session, gate by gate
  • 👀 Visible to your coach, like any track session
Virtual timing gates placed automatically along the sprint in the RAD 4 BMX app: time between two gates compared over several runs, best highlighted

Virtual timing gates placed automatically along the sprint — the time between two of them, compared to the best run.

For coaches

For the coach, the same data changes scale.

The speed, acceleration and cornering angle measured by each saddle aren't only useful to the rider using it. A coach linked to several riders gets the same data compared moto after moto, session after session — enough to measure a difference in line or re-acceleration rather than guess it from the side of the track.

See coach pricing

What the coach does with it

  • Live tracking of riders on race day
  • Race results tracking
  • Fitness tracking, session after session
  • Progress tracking over time
  • Interactive creation of training programmes
Manufacturing

Custom machining, not a modification.

01

Machining the cavity

The underside of the pivotal saddle is machined to create a cavity sized exactly for the sensor and the battery.

02

Electronics integration

The RAD Signal sensor and its USB-C rechargeable battery are positioned in the cavity.

03

Fixing the housing

The housing is permanently fixed under the seat — the electronics become part of the saddle, protected from impacts.

RAD Signal sensor housing fixed under the seat
The RAD Signal housing, permanently fixed under the seat.
Underside of the connected saddle, RAD BMX plate and pivotal mount
The pivotal mount stays standard: it fits like any other saddle.

The USB-C charging port remains accessible from the outside to charge the battery without taking anything apart.

€99 + €29 + delivery

Saddle, sensor and battery — paid once. The Rider subscription then starts as soon as you pair your saddle.

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