Zéfal Spy

The Zéfal Spy has for years been the top-selling entry-level mirror at Decathlon, major online retailers and most Dutch bike shops, for two clear reasons: it fits almost anywhere and costs less than lunch. Zéfal is a French brand with a long track record in small bike accessories — pumps, bottle cages, mudguards — and the Spy is their shot at a mirror market historically dominated by German and American brands. The clamp is a simple rubber strip pulled tight with a single bolt, which makes the mirror immediately accessible: whether you have a 22.2 mm city-bike bar or a 31.8 mm flat bar on a modern hybrid, the Spy just fits. In use the image is adequate — no more, no less. On a quiet cycle path at 18 km/h you can clearly see an approaching electric cargo-bike parent or a hurrying e-bike commuter. The field of view is a good 20 degrees, plenty for standard urban riding. But the moment you cross cobbled stretches in an old city centre or a rough concrete path along a canal, the long arm visibly resonates. The image turns into a vibrating, smeared version of what is actually behind you — still usable for ‘is something there?’ but not for ‘how fast is it approaching?’. The plastic mirror lens also yields a slightly softer, less sharp image than real glass, and in rain water beads on the lens surface and diffuses the reflection further.

Against competition the Spy sits squarely in the cheap tier. The Busch & Müller Cycle Star 80 offers clearly better optics and damping, but costs almost twice as much and needs an open bar end. The Zéfal Z-Eye (a larger sibling in the same brand) has more lens area but still plastic optics. Sprintech mirrors are a sportier solution for road riders with a tiny convex lens in the bar plug, but a different category. For a cargo-bike parent who occasionally glances back on the school route, or an e-bike commuter mostly on wide cycle paths, the Spy is exactly enough — not outstanding, but functional and not a loss if it gets knocked at the bike rack.

Honest caveats: for speed pedelec riders, who legally need dependable rear vision before merging into 45 km/h traffic, I would not recommend the Spy. At those speeds and vibration levels a proper glass mirror on a bar end is genuinely necessary. The rubber strap stretches noticeably after two Dutch summers of sun and then starts rotating — time to retighten the bolt or, realistically, replace the mirror. Finally, the ball joint in the arm usually loses some grip after six months, and then you end up re-aiming the mirror after every cobbled stretch.