ROCKBROS Q3 Rear Bike Light with Smart Brake Sensing - Black

With a 60-lumen COB LED and a 180° beam, the ROCKBROS Q3 rear light makes you visible from up to 1000 meters away. Its intelligent G-sensor detects deceleration and automatically boosts brightness to alert drivers behind you, acting as a brake light. The built-in light sensor turns the light on in darkness and off in daylight, saving battery for when you need it.

Overview

The ROCKBROS Q3 is a compact, USB-C rechargeable rear bike light designed for commuters and road cyclists. Its aluminum alloy and PC body withstands daily use, while the IPX6 waterproof rating keeps it working in heavy rain. A silicone strap mounts securely to seatposts from 25.4mm to 31.8mm without tools.

What stands out

• Smart brake sensing: G-sensor detects braking and switches to a constant high-brightness mode, mimicking a car brake light.
• Auto on/off: Light and motion sensors automatically turn the light on in low light and off when parked, extending battery life.
• Five lighting modes: Constant, Breathing, Flash, Strobe, and SOS—choose the best for day or night riding.
• Long runtime: Up to 50 hours in flash mode on a single charge, with a low-battery indicator to warn you.
• Wide visibility: 180° beam angle ensures side visibility at intersections and roundabouts.

Technical details

• Light source: COB LED, 60 lumens
• Beam angle: 180°
• Battery: 400 mAh lithium-ion, USB-C rechargeable
• Charging time: approximately 2 hours
• Runtime: up to 50 hours (flash mode)
• Water resistance: IPX6
• Material: aluminum alloy + PC
• Mount: silicone

Our verdict

The ROCKBROS Q3 combines smart brake sensing, automatic on/off, and long battery life in a rugged, waterproof design—an excellent choice for safety-conscious cyclists.