Are integrated helmet lights bright enough to replace a separate rear bike light?

Integrated helmet lights vary significantly in brightness and visibility. Basic integrated LEDs (typically 5–20 lumens) supplement but don't replace a proper rear bike light (50–100+ lumens). Premium e-bike helmets with high-output integrated lights (30–50+ lumens) may be sufficient as a primary rear light for urban riding with street lighting, but a separate frame-mounted light remains recommended for dark roads and higher-speed traffic. The key advantage of integrated lights is that they're always available and properly positioned—they're a reliable backup even if you also run a separate primary light.