You are planning a Sunday loop through the back roads and you do not want a glowing 7-inch slab on the bars — you want speed, the next turn, and your trip mileage, and nothing else.

You park the bike outside a café, glance back at the bars, and there it is: a bright 7-inch screen sitting in plain view, bolted to the handlebars, basically advertising itself to anyone who walks past.

You roll onto the on-ramp, glance down at the bars, and your route is right there — but so is the slow rear tyre you topped up two days ago, holding 34 psi and warming through 38 °C as the miles tick by, in a small strip beside the map.

You do it right every time: bike cold in the garage, pencil gauge on the valve, front and rear set to spec before you roll out.

You are twenty minutes into a Saturday loop, stopped at a junction you did not expect, poking a phone screen with a wet glove while the battery slides toward orange.

The bolt is home, the clamp feels tight, and you still watch the screen nod at every seam in the tarmac. Or you drop off a kerb and the computer is face-down in the grass behind you.

Six in the morning, and the phone is clamped to the stem before you have even clipped in. By the cafe stop the screen has dimmed in the sun, the battery is down a third, and there is weather stacking up over the ridge.

You and a friend roll out together, ride the same loop, stop at the same café — and the two computers on your bars disagree about how far you just went. Neither of you took a detour. It happens often enough that Strava keeps a help page devoted to the question.

Search for a wireless bike computer and you get three machines that barely belong in the same category: a head unit listening to a magnet sensor near the fork, a GPS unit that needs nothing on the wheel, and a round display that is really a second screen for the phone in your pocket.

Three lanes of wet interstate, traffic bunched up, spray coming off every truck. You check the mirror, see nothing, start to move over — and the car sitting exactly in the gap your mirror does not cover leans on its horn.