A team from Slovenia are launching on Kickstarter a bike computer that fits inside a steerer tube. The small circular screen replaces the top cap and displays all the usual metrics you'd expect from a GPS bike computer - elevation, speed, heart rate and so on. As well as keeping it out of harm's way inside the bike, so there's no risk of hitting it with your knee and watching it bounce off down the trail; this design also allows for a much larger battery to be housed inside the fork and below the screen.
The 2600 mAh battery is claimed to last around 3 months, and as long as there's enough charge left, you don't have to do anything; it starts recording automatically when you start riding. It's designed to be a set and forget device, more like the dashboard in a car than existing bolt-on devices which usually need charging after every ride.
The unit replaces a conventional top cap and star nut, which preloads the headset. A bolt threads into the bottom of the unit, and together with a cap on the bottom of the steerer, this compresses the headset. That means there's no need to cut threads into the steerer tube, just tap out the star nut and install the computer with an Allen key.
The 1.3” round screen (240×240 pixels) can't display a huge array of information at once, but a radial wheel makes it possible to scroll through up to five pre-set data fields, which can display things like speed, altitude, sensor data as well as turn by turn navigation and notifications (if desired). It interfaces with an app (Android and IOS) for a more comprehensive breakdown of post-ride stats, which links with Strava, Google maps, Gopro and Komoot.
The device houses a barometric sensor for precise altitude data, but uses your phone's GPS hardware for location information. Finally, there's a clever take on a traditional magnetic odometer, which uses a magnetic valve cap and no wires. This offers more precise, real-time speed data than GPS. CoreCap is also compatible with BLE (Bluetooth Low Energy) devices such as heart rate and cadence sensors.
For more information check out the Kickstarter page.