Overview

The Garmin 010-12103-00 is a hub-mounted bike speed sensor that sends wheel-speed data over 2.4 GHz ANT+ so a compatible device can calculate speed and distance even when GPS reception is poor.

It straps to the hub of either wheel and wakes up automatically when the wheel turns. The sensor is water rated to 1 ATM (pressure equivalent to 10 m) and operates from -20 to 60 C, which covers rainy rides, indoor trainer use, and storage in a cold garage.

Key features

• Strap-on hub mounting for front or rear wheels; a slight tilt on an asymmetrical hub does not affect operation.
• 2.4 GHz ANT+ wireless communications for pairing with compatible Garmin and other ANT+ devices.
• User-replaceable CR2032 3 V battery with approximately 12 months of life based on 1 hour per day use.
• Water rating: 1 ATM (pressure equivalent to 10 m) for rain and splashes.
• Status LED confirms activity after wheel movement and indicates low battery.

Installation and setup

Place the sensor on top of the wheel hub, wrap the strap around the hub, and hook it to the sensor. Spin the wheel to confirm it has clearance from spokes, fork legs, and brake hardware; after two revolutions the LED flashes green for about five seconds to show it is awake and sending data.

Pair it through your ANT+ compatible device menu. Keep the sensor within about 3 m during pairing, and stay about 10 m away from other ANT+ sensors while completing the first connection.

Compatibility and fit

This is a bicycle wheel speed sensor, not a thru-hull or paddlewheel transducer for boat instruments. It communicates using ANT+ and is meant to be paired to a compatible Garmin Edge or any other ANT+ device that supports speed sensors.

Because it mounts at the hub, it works with either wheel and can be moved between bikes by transferring the strap. If the hub shape causes the sensor to sit at a slight angle, normal operation is still expected as long as the wheel rotates freely without contact.

Use on board

If you keep a bike aboard for dock runs, this sensor is a practical way to record speed and distance without relying on GPS, including on an indoor trainer. After salt spray or a wet dinghy ride, rinse with fresh water and dry before stowing so the battery cover and seal stay clean.

The unit is rated to 1 ATM for splashes, but 2.4 GHz wireless signals do not transmit through water. Avoid using it submerged or leaving it soaking.

Maintenance and care

When the LED flashes red after wheel movement, replace the coin cell. Twist the rear cover to the unlocked position, swap in a CR2032 (3 V), keep the O-ring in place, then twist back to locked. After a battery change, wait about 30 seconds before reassembling so it restarts cleanly.