It's one of the highest ranked for good reason. Can't go wrong with this. Smallish size but big enough too.
Positives: Compact to 830 much improved connectivity with iPhone. Screen sensitivity much improved. Climb pro is a huge plus. Battery life is much better. Combo of buttons and touch screen is very nice upgrade.
For the negatives/reason for 4stars: Lap time resets every hour. There is a numeral in the corner of the field that designates 1st ,2nd, etc hour. Took a while to figure that out despite calls to Garmin tech support.
Power drops to zeros while pedaling for 5 seconds or so. Makes overall power lower than actual. Garmin sending a replacement unit due to this issue.
I use the 840 for both trainer rides and outdoor rides. Use of the touch screen required getting familiar but the capabilities of this unit are exceptional. Connection to all sensors is much more robust and satellite routing is spot on. Swiping / selecting profiles is quick and easy and available data screen choices exceeds previous versions.
I bought this computer to replace my 530 edge that died after 3 years. I'm a roadie riding 150-200 miles a week. I love this computer. It was way more features that I need or use but a great computer overall. Didn't think that I needed touch screen ... wrong! Glad I got that feature. Integrates perfectly with my Varia headlight and rear radar light.
I've had three or four previous versions. This is the first 800 series. Simply the best. Smooth functioning, great touch screen that works even in the rain. Great mapping capabilities. Solid product all around.
I came from a Wahoo ELEMNT Bolt v1 which is great, but suffered from poor elevation readings. Have a Garmin watch and wanted to try the Garmin cycling computers. The 840 is must better computer: Easy to use and customize, better accuracy, and touch screen! Would recommend this to anyone.
More intuitive than previous versions. Faster than previous versions. Still has the issue where the altimeter/elevation calculator does work in the rain. Navigation still a bit wonky, especially on re-routing. Sporadic connectivity with my Garmin headlight, sometimes it connects, sometimes it doesn't. All in all an upgrade, but Garmin still has some bugs to work out.
The new UI would take some time to get used to but I like added feature of workout suggestion and detours in one click. Overall I'm very pleased with upgrade.
