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Hammerhead Karoo 2 review

1 Jun 2022

Smartphone-style interface, excellent connectivity, and brilliant mapping make this GPS computer a very smart proposition

Cyclist Rating: 
Easy to use, stunning screen • Good battery life • Excellent mapping
Slightly fewer performance features than some rivals

Not that you shouldn’t stick around for the rest of the review, but the Hammerhead Karoo 2 is by some distance the best GPS bike computer I’ve ever used. Not only does it do everything you’d expect of a premium GPS unit, it does so with a stylish and user-friendly interface that looks and feels more intuitive than its rivals.

To manage this trick, the Karoo employs a custom version of the Android operating system found on many smartphones, meaning it’s responsive and familiar feeling from the off.

It’s the first bike computer I’ve seen that also offers a smartphone-like level of usability. Twinned with great design, a vivid, high-resolution display and decent pricing at £359, it’s already a good way ahead of any of its rivals.

Hammerhead Karoo 2 key features and specs

  • Android operating system and quad-core processor
  • 2Gb RAM, 32Gb storage
  • Excellent mapping with turn-by-turn directions
  • Full-colour 3.2-inch touchscreen display + supplementary buttons
  • In-device route-to feature
  • ANT+, Bluetooth, and Wifi connectivity
  • Syncs with Strava, RideWithGPS, Komoot, TrainingPeaks, Strava
  • Circa 12-hour battery life,
  • Regular firmware updates
  • Notifications, Live Tracking, and Climber features
  • £359 price

Hammerhead Karoo 2 technical specifications

Let’s start with the headline specs. The Karoo 2 has a quad-core processor, 2Gb of RAM, and 32Gb of storage. It also runs a custom version of Android 8. In terms of connectivity, it boasts dual Bluetooth Smart chipsets that allow it to record from any number of paired devices, while it’ll also support up to seven ANT+ accessories.

It’ll connect to both GPS and GLONASS for location, while a barometric altimeter, temperature sensor, three-axis accelerometer, and gyroscope make for accurate readings. Charging is achieved via a USB-C port.

Hammerhead Karoo 2 physical features

Weighing 132g and measuring 60x100mm, the Karoo is smaller than a Garmin Edge 1030 Plus and a bit bigger than a Wahoo Roam or an Edge 530/830. As you’d hope, most of its face is taken up by an 82mm (3.2inch) screen.

This has a 480x800 pixel resolution and can display a massive 16.7 million colours. The same sort of display you’d expect on a high-end smartphone, the result is pretty stunning.

Protecting it is a Dragontrail Glass layer that’s pleasingly matt, making it easy to read even in direct sunlight or rain. Its entire width is touch-sensitive, while on either side, you’ll find two rubberised buttons to aid in its operation—a great feature when wearing gloves or riding on bumpy surfaces.

The device comes with a proprietary mount which clicks together with an affirmative clunk and seems robust.

Having used it for moderately gnarly mountain biking, I reckon it should be fine for road or gravel-based adventures. Those with existing Garmin style mounts will also find an adaptor in the box.

Powered by a 3200mAh Lithium-Ion Polymer cell, claimed battery life is around 12-hours. Full charging takes about three hours, with 30% being reached in half an hour and 50% taking an hour.

Using the Karoo 2 in power save mode, I found it automatically woke up when needed (such as before a turn or at the start of a climb). Employed in this way, I managed more than an hour over its stated maximum when using it paired with just a heartrate sensor. However, what you achieve will vary depending on sensors used, ambient brightness, and other variables.

Hammerhead Karoo 2 routing, mapping, and navigation

This is a definite strong suit for the Karoo. If needed, you can look up an address or drop a pin, and the Karoo will find a way there regardless of internet connection. However, while this is extremely useful for getting out of sticky situations, most of your route-related admin is likely to be done on your phone or computer via Hammerhead’s web page-based dashboard. Here you can import routes from services like Strava and Komoot.

Alternatively, you can harvest routes directly from web pages, making it easy for friends to send you suggestions by sharing their URL. There’s also a drag and drop import feature that supports gpx, fit, tcx, kml, and kmz file formats.

There’s some ability to edit and create routes online. However, most users will probably stick to their preferred route editing software, assuming they already have one. Obviously, you’ll need to be connected to the internet to manage any of this. Once imported, routes rapidly make it from the cloud to your device. Once there, they can quickly be sorted by variables, including proximity, elevation gain, or distance.

The on-device mapping itself is fantastic and very clearly rendered. Based on OpenStreetMap, I found the Karoo knew where everything was. Even off-road, trails were often more apparent on the device than on the ground. With 32Gb of internal storage, there’s plenty of space to store different regions. Downloadable directly via the device, these map packs are free and can be added one country at a time.

In use, I found the Karoo quickly connected to its satellites. Once following a set path, both auditory and visual turn alerts come in good time and are easy to follow. If you do stray off course, the Karoo will beep to let you know and reroute quickly without excessive drama.

Hammerhead’s Climber feature is also very ingenious. It automatically generates a preview of any climbs on your route. Counting them down as you roll along, the gradient of each is broken down into readily comprehensible 100-metre sections. With each colour-coded, this allows you to gauge your efforts perfectly and is a great feature when you’re riding in unknown terrain.

KOM hunters will also find themselves similarly well served by the unit’s ability to guide you through Strava Live Segments in real-time.

Hammerhead Karoo 2 LiveTracking and other features

If you want to let people know where you are during a ride, the Karoo features LiveTracking. Cleverly, the person following you doesn’t need a Hammerhead account. Instead, each time you turn the service on, it generates a custom URL you can send to let them follow your progress on a map.

You’ll need to tether your phone to connect to the internet, although there’s also a SIM card slot if you want to enable features like syncing and LiveTracking without having your mobile in range.

Connecting to a vast host of different sensors means the Karoo is just as good for data fiends as it is for adventurers. Again we found its connections to be almost infallibly stable. The way this data is displayed is also excellent. With the ability to custom build displays for different profiles, each presents your information cleanly and logically. It’ll also generate colour-coded graphics for metrics like heart rate or power, rather than just spitting out a simple number.

Fitness users will also appreciate its ability to guide you through structured workouts. These can come via Zwift or TrainerRoad or be imported via the web-based dashboard, assuming they come in the Fit or Zwo format. You can then use the Karoo to control the resistance on an ANT+ trainer or work through the plan outside.

Hammerhead Karoo 2 downsides

I’m struggling to think of negatives. One thing I did miss was the ability to reverse routes stored on the device. Given that you can navigate without connecting to the internet, this seemed odd. It’s easy enough to do via your phone, although that’s no use if you’re in a data blackspot.

Some performance-minded riders might miss out on the depth of attributes offered by Garmin, such as the more detailed ClimbPro feature. Wahoo riders will also have a slight advantage when it comes to making routes up on the fly via the brand’s companion app.

On one occasion, either because I’d gone off route or because I was on a climb, the screen didn’t automatical cut out when I stopped at a cafe, and so ate a load of the battery. However, I’ll know to check this and do it manually in future.

Finally, the USB-C port is protected with a loose rubber bung, which is guaranteed to go missing. This means that despite the unit’s IP67 rated waterproofing, mud getting in may be an issue if you ride off-road.

Otherwise, that’s about it.

Hammerhead Karoo 2 verdict

In our experience, the Karoo really could be all things to all riders. Smaller than the largest bike computers, it’s still easily big enough to follow complex routes and play around on the road. At the same time, it’s not so large as to be cumbersome for those more interested in using it for live metrics and training. The battery life is solid, and the display is stunning. Plus, it has a great features list. Still, there’s something else that sets it apart.

Chatting with a software engineer friend, he helped me nail down in nerd terms what other brands are currently lacking. In his words, “they feel like the software designers have written the whole system, including the UX (user experience) part”. In normal person speak, this means that while the functionality is there, it’s that final polish that’s lacking.

By comparison, Hammerhead has got this bit down. It’s often said that the test of a well-designed interface is if your nan could navigate it. I wouldn’t put my skills with technology ahead of the average grandparent, yet I managed. In fact, the Karoo is so smart it largely sets itself up. One result was that I found my ride being interrupted by texts and email alerts until I discovered how to turn them off.

Almost everything works as you’d expect it. Features you’d like to see are almost universally catered to, and accessing everything seems pretty logical. Plus, it looks great in terms of hardware, web-based elements, and its display and graphics.

So the Karoo is already very, very good. However, it could also improve with time. For one thing, Hammerhead is committed to releasing twice-monthly software updates. Secondly, the Karoo’s Android operating system means other developers could start releasing apps for it.

In fact, if you’re some Neo-in-The-Matrix level hacker, you can currently side-load things like the Zwift Companion app. Given that Hammerhead is already carving itself a big market share, more dedicated apps appearing in the future seems likely.

All considered, it’s a great device with the potential to get even better.