The Edge 840 sits in Garmin’s lineup between the button-only Edge 540 and the larger Edge 1040, and after several weeks of mixed road and gravel riding, it’s easy to see why this middle spot is where most riders should be shopping.

Setup and first impressions

Out of the box, setup took about ten minutes - pairing a power meter, heart rate strap, and phone all went smoothly through Garmin Connect. The touchscreen is responsive from the first tap, a real improvement over older Edge models that felt sluggish.

Touchscreen in real conditions

Touchscreens on bike computers have historically been a weak point - unreliable with gloves, unusable in the rain. The Edge 840 handles both noticeably better than its predecessors.

  • Screen taps registered reliably with lightweight cycling gloves.
  • Light rain didn’t cause phantom touches or missed inputs during a 90-minute test ride.
  • A physical lock mode is available for heavy rain or technical terrain, falling back to button control.

Where it still struggles

In a genuine downpour, the touchscreen becomes less reliable, which is exactly when the lock mode becomes useful rather than optional.

Battery life and solar charging

Garmin claims up to 26 hours in standard GPS mode, extending to roughly 46 hours with solar charging in direct sun. In practice, over a week of 90-minute daily rides in mixed sun and cloud, the unit lost noticeably less battery on sunny days - enough that solar meaningfully extends the charging interval rather than being a marketing footnote.

Mapping and navigation

Turn-by-turn navigation with rerouting worked reliably on both road and gravel routes. The preloaded maps are usable out of the box, though riders in less-mapped regions will want to update map data manually for the best routing accuracy.

Verdict

The Edge 840 earns its place as the sensible middle option in Garmin’s lineup: touchscreen convenience without giving up the reliability that made button-only models popular, solid battery life, and navigation that holds up on real routes. It’s not the cheapest bike computer, but it’s the one we’d point most riders toward.