Garmin Varia RearVue 820 review: a genuinely next-gen bike radar

Garmin has launched the Varia RearVue 820, a significant upgrade to its well-regarded bike radar line, following a six-year gap since the RTL515 model. The new unit introduces a leap in radar technology by switching from 24 GHz to 60 GHz waves, which dramatically improves detection accuracy and responsiveness. This advancement allows the device not only to track vehicles approaching from behind but also to differentiate between types of vehicles and their lane positions, a feature that sets it apart from competitors and earned it top marks in Cycling Weekly’s group test. In terms of design and construction, the RearVue 820 adopts a more modern and robust aesthetic, moving away from the previous black slab look to a sleeker form with bevelled edges and transparent polycarbonate lenses for enhanced visibility. The device now features a USB-C charging port, a long-overdue update from the outdated Micro-USB of its predecessor, and includes a removable rechargeable battery to comply with upcoming EU regulations. These changes improve both the unit’s durability and user convenience, especially for cyclists who rely heavily on frequent charging. The RearVue 820 also offers improved lighting, with brighter output across various modes including day flash, night flash, and peloton mode, enhancing rider visibility without compromising group riding comfort. However, some of its advanced features are only fully accessible when paired with modern Garmin head units, limiting the experience for users with older or non-Garmin devices. Additionally, while it supports ANT+ protocols, the gradual phasing out of ANT+ may affect future compatibility and feature availability. Despite its premium price tag and some arguably excessive features, the RearVue 820’s precision and reliability make it a compelling choice for cyclists prioritising safety and technology. Garmin’s renewed commitment to innovation in bike radar technology positions the RearVue 820 as a best-in-class device, though potential buyers should weigh the cost against their specific needs and equipment compatibility. The introduction of this next-generation radar signals Garmin’s intent to remain a leader in cycling safety tech as the market evolves.