If you want a discreet and waterproof GPS tracker for your bike, Invoxia has a good product. Its Bike Tracker is designed for cycling, with live location updates and alerts if it's stolen. It's small and waterproof, so it should work regardless of the weather. It's got other features, too, like long battery life and international coverage, so it's a good choice if you want to keep an eye on your bike as you ride.
Another good option is Petcube, a pet-focused company that also offers GPS trackers that can give you real-time location updates and alerts if your pet escapes. Its system includes geofencing, proximity alerts and a history of where your pet has been, so it's a good option if you want to track your bike. It's geared for pet owners, but the GPS tracking abilities are strong enough that you can use it if you want a more powerful, feature-rich option.
If you want a more general-purpose family locator service, check out GeoZilla. It's designed for finding family members, but it also works with wearable GPS trackers, including pet and car models. The service offers live location updates, crash detection and safety reports, and it's a good option if you want to keep tabs on your bike and other assets.