A crowd-network tag and a SIM tracker fail in completely different places
Two entirely different devices share the word tracker. A crowd-network tag has no GPS and no SIM: it reports only when someone else's phone passes near it, which works well in a city and not at all on an empty road. A SIM-based tracker reports its own position anywhere with mobile coverage, at the cost of a subscription and a battery measured in days rather than a year. We compare which network a device uses, whether a subscription is required, the ingress rating where one is stated, and how well the unit hides — inside a fork steerer, under a saddle, behind a bottle cage or built into a rear light. None of the five publishes a battery life figure, tag or tracker, so we do not print one.
8.4 × 3.9 × 1.1 cm (3.3 × 1.5 × 0.4 in) · ABS · bottle boss mount · screws and key supplied
A concealed AirTag holder that mounts under or in place of a bottle cage, in ABS, supplied with two 25 mm (0.98 in) M5 screws and an Allen key.
Best for: Hiding a tag on a bike that already has bottle bosses, at minimal cost.
Fork steerer 32–38 mm (1.26 to 1.50 in) internal · injection molded in Germany · doubles as a plug
A holder that hides a tag inside the fork steerer of a mountain bike, fitting internal diameters of 32 to 38 mm (1.26 to 1.50 in) and doubling as a plug against dirt.
Best for: Mountain bikes with an open fork steerer, where the most invisible hiding place is the point.
Under-saddle mount · ABS · AirTag 1 and 2 · universal saddle fit
An under-saddle AirTag holder in ABS, stated to fit almost any saddle across mountain, e-, road and city bikes, and compatible with both AirTag generations.
Best for: Any bike, because it needs no measurement — the fallback when the fork and bottle cage options do not fit.
31.8 mm (1.25 in) bars only · 85 dB bell · AirTag 1 and 2 · tools included
A working 85 dB bell with an AirTag concealed inside it, for 31.8 mm (1.25 in) handlebars only, supplied with the tools to fit it.
Best for: Bikes that need a bell anyway, on 31.8 mm (1.25 in) bars, where one product solving two problems is the appeal.
4G real-time tracking · fall alarm · IP67 · 3 months subscription included
The only true GPS tracker in this hub: a 4G unit built into a rear light, with real-time location, route recording, motion and fall alarms, and three months of subscription included.
Best for: A valuable bike, or riding where a crowd network is useless — rural roads, quiet times, long distances.
≈ $50
A tracker is only of use if it stays hidden and charged. How well it integrates into the bike and how long it runs decide whether it is any use at all.
A proximity tracker with no subscription relies on a network of nearby devices and costs little.
A visible tracker is removed in ten seconds and serves no purpose after that. The stated dimensions decide whether it fits in a stem, under a saddle or in a bottle cage.
It gives a position to pass to the police. Going to recover a stolen bike yourself is inadvisable and sometimes dangerous.
Proximity trackers do not need one and depend on nearby devices. SIM-card trackers require one and work anywhere with a signal.
Under the saddle, inside a stem, in a dummy bottle cage. A visible tracker is removed in seconds.
From several months on coin-cell models to a few weeks for active trackers. A flat tracker is no use at all.
Never. The lock prevents the theft, the tracker records it. They do not answer the same question.
Registered marking allows a return and deters resale. It complements the tracker rather than duplicating it.
In a garage or a cellar the signal gets through badly. That is a real limit of the format.
It gives a position, which is information to pass to the police: going there alone is not a good idea. Recovery depends on the procedure, not on the device.
The tracker records the theft, the lock prevents it: they do not answer the same question. A visible tracker is removed in seconds, a proximity tracker is silent in the countryside — and a position is passed to the police, not acted on yourself.
There is no table here, and the reason is in the listings. The figure published most often across these 5 products is compatibility, given by 3 of them — short of the four in five a column needs to compare rather than to display gaps. Each product page says what its own maker published.
Specifications: manufacturer sheets for bike gear and the matching Amazon product pages. Prices and availability: Keepa.
Most recent revision in this category: August 30, 2026.
