A few years ago I bought my husband a Garmin Edge bike computer for Father’s Day. He’s used it on every ride since then, so we were both excited to test out the Garmin Edge 840 solar bike computer. I thought the 530 had a lot of features, but the 840 is quite an upgrade. It has solar charging, a larger colour touchscreen display with buttons, and you get access to a few new Garmin features I’ve never seen before. Here’s a look at what we thought of the Garmin Edge 840.

Features on Garmin Edge 840 bike computer

The Garmin Edge 840 is a bike computer that’s meant for all kinds of biking. You can use it with road bikes, gravel bikes, mountain bikes, electric mountain bikes, or indoor exercise bikes. It includes two mounts, a tether, a cable for charging, and two hex keys to tighten the mounts. It has a screen resolution of 246×322 pixels and the measurements are width – 5.78 cm (2.28 in), height – 8.51 cm (3.35 in), and depth – 1.96 cm (0.77 in).

Garmin Edge 840 what's in the box
  • Colour touchscreen with button controls lets you choose how you want to navigate
  • Rechargeable battery gives you 26 hours of riding time, up to 32 hours when you use solar charging by placing your device in direct sunlight, and up to 60 hours in battery save mode
  • Uses multi-band GNSS technology to log your location accurately and will navigate you back to your start position if you get lost
  • Displays bike-specific maps to help you find places to ride wherever you go
  • ClimbPro ascent planner lets you know how long a trail’s climb is, how long you still have to ride, and what grade your current uphill climb is
  • Offers daily workout suggestions and will prompt you if you miss a workout
  • Measures mountain biking metrics including elevation, hang time, grit, and flow
  • Pairs with Garmin heart rate monitor and other Garmin accessories to measure your power and help you improve your stamina
  • Pairs with the Garmin app as well as Strava and other fitness tracking apps
  • Shows your calls and messages so you can keep your phone safely stored away

Setting up the Garmin Edge 840

Garmin Edge 840 with out front mount

Garmin included two mounts with the Garmin Edge 840: an out-front mount that extends beyond your handlebars and the quarter turn mount that places the computer right on your handlebars. We started by installing the Garmin Edge 840 using the out-front mount. It’s a fairly easy install process where you just tighten the mount to your handlebars. One of the benefits of the out-front mount is that you get a great view of the screen as it extends quite a bit. It’s easy to reach out and touch when you’d like to change something on the screen, and we found it was easy to access the buttons too.

The computer is very stable on the out front mount, but as we used it mostly for mountain biking we decided to switch to the quarter turn mount with tether. Crashes are almost guaranteed on a mountain bike, and it felt like the quarter turn mount was a safer option for keeping the computer out of harm’s way. If I was riding a road bike, gravel bike, or indoor bike, the out front mount would be my choice.

We always used the tether to attach the bike computer to the bike. I’ve heard of a few people who have lost their bike computers when they crashed and it flew off, so I think it’s a good idea to keep it connected. That being said, the Garmin Edge 840 also has a locate feature called Find my device. If you lose your device, you can use the Garmin app to locate it.

Testing the Garmin Edge 840

Garmin 840 side buttons

The first thing we noticed after unboxing the Garmin Edge 840 was the size of the computer itself. It’s slightly larger than our 530 model, and I really the bigger size. It’s much easier to see when you glance down. There are two Garmin Edge 840 models, one with solar charging and one without. We tested the model with solar charging.

I love the colour touchscreen on the 840, and thought the buttons on the sides were a nice touch too. The touchscreen was easy to use, but if you’re used to buttons you can choose how you want to navigate the screens.

Analyze every second of your trail time

Back to start with Garmin Edge 840

Any Garmin Edge bike computer is going to offer an almost overwhelming amount of data. They are the best bike computers for mountain biking because they really don’t miss a single detail of your ride. We used it for mountain biking but you can switch it between different bikes too. For mountain biking it tracks your jumps, calculates your hang time or how long you were in the air when you were jumping, and stores data so you can compare how well you rode the trail over time.

Grit, Flow, and more

Grit and Flow are two important metrics the Garmin Edge 840 will track, with Grit being how hard the trail is and Flow how smoothly you rode it. I’m not great on a mountain bike, but one of the reasons it’s good to have a bike computer is that it’s encouraging to see the flow score improve over time. You can do a trail over and over again and see how much better you’re getting.

Grit and Flow Garmin bike computer

The Garmin Edge 840 also has another feature I really like—Back to Start. The computer uses multi-band GNSS technology to track you turn by turn, so if you’re like me and you often get lost on a new trail, the Edge 840 will lead you straight back to where you started.

Speaking of the GPS on the Garmin Edge 840, I am blown away by how accurate it is. When Garmin says you can ride like a local using their trail maps, they aren’t kidding. Even if I had no idea where I was, the bike computer knew. While there is the occasional GPS drift if you’re in the middle of thick trees, it can still keep you on the trail by mapping you turn by turn. It’s like having the Trail Forks app right on your bike, and it definitely made me more confident to get out and explore. You don’t have to worry about getting lost because it pinpoints where you started riding and Back To Start will lead you straight back to your start location.

ClimbPro stays with you until you reach the top

Garmin Edge 840 solar bike computer review

Garmin ClimbPro ascent planner is a really cool feature on the Garmin Edge 840. When you’re riding it will show you where you are in relation to any upcoming climb. It automatically shows the distance, grade, and ascent of the climb, and it updates you along the way. I liked how it automatically appears on the screen as you approach a climb, but I’ll admit I didn’t spend a lot of time looking at it when we were climbing a hill. Some of the hills my husband takes me up are steep, and I just put my head down and stop thinking until I’ve hit the top. My husband loved the feature. He likes the data and is a big fan of elevation metrics.

Regain your battery power with solar power

Solar power gain Garmin Edge 840

The Garmin Edge 840 uses solar power to recover your charge when you’re out riding. It has power glass to capture sunlight, and according to Garmin it can give you an extra 25 minutes of use per hour. The thing to keep in mind is that you still need to charge it via USB-C before using it because it still uses power while you’re riding. You can see the power used and the power gained by sunlight, and depending on how strong the sun is, it’s usually more power out and less power regained. Solar is only meant to top you up so it doesn’t run out of battery when you’re riding.

We didn’t drain the battery when using the Garmin Edge 840 over the course of a week, but there are a few different features that run your battery low. If you’re trying to conserve you may want to turn off call and message updates as that may cause your battery to drain faster. You can also dim the screen so it’s not as bright. I liked having the brightness turned all the way up. It’s much easier to see in bright light.

There is a battery saver mode that turns off the backlight and extends the battery for up to 60 hours. That’s the mode you may want to use if you’re away from power for a few days and you’d like to keep your bike computer running.

Add Garmin accessories to access more features

There are a features on the Garmin Edge 840 that require the use of additional accessories. You can add a power meter to your bike to assess how much effort you’re putting into your ride, and you can pair a Garmin heart rate monitor with the bike computer to see your heart rate. When you add accessories you can unlock adaptive coaching and daily workouts. We didn’t get to try it for ourselves, but it sounds like a great feature. It can assess your ride and help you improve your time or strength. I also like the idea of seeing your heart rate on the computer so you can have a better idea of how hard your heart is working when you climb or ride.

Should you choose the Garmin Edge 840?

Garmin Edge 840 local ride maps

Out of all the Garmin Edge bike computers I’ve tried, I think the Garmin Edge 840 is my favourite model so far. My husband had the same opinion. We both liked the colour touchscreen and buttons, and you can use one or the other depending on your preference. With the backlight on the screen is quite visible in bright light, and the size of the display is easy to see when you’re riding.

There are so many metrics you can track with the Garmin Edge 840 that it feels a little overwhelming when you start using it, but you’ll be glad you have them. This would be a great bike computer if you’re just starting out biking because you’ll have baseline data and you can see over time just how much you’ve progressed. It’s very motivating.

You can find the Garmin Edge 840 solar bike computer at Best Buy right now.

Shelly Wutke
Editor TV & Home Theatre
I'm a Vancouver freelancer and tech enthusiast. When I'm not writing you'll find me on my farm with my alpacas, chickens, and honeybees. Visit my website Survivemag