The Hammerhead Karoo is the third generation of the American manufacturer’s bike computer, following the Karoo 1 and Karoo 2 – though the naming convention has taken a somewhat winding path. Since Hammerhead were acquired by SRAM in 2021, it’s no surprise that the software has been optimised for seamless integration with the SRAM AXS ecosystem. But what does that really mean in practice – and why might one major drivetrain brand not be too happy about it? We’ll get to that later. First, let’s talk about hardware.
Out of the three models we tested, the Karoo is the smallest and lightest – although all three are fairly big by bike computer standards. The 3.2-inch touchscreen has the highest pixel density in this test field thanks to its 480 x 800 resolution, promising the sharpest image of the lot. It also features a brightness sensor that automatically adjusts backlighting, while the lightly matte screen helps reduce glare in direct sunlight for better visibility.
Alongside the touchscreen, the Hammerhead Karoo generation 3 also features five physical buttons, covering all essential functions during a ride. So even if it’s raining or you’re wearing thick winter gloves, you can still operate the device without having to touch the screen.
At just 117 grams, the Hammerhead Karoo undercuts its main rivals by quite a margin. It’s 30% lighter than the Garmin Edge 1050 (160 g) and a whopping 44% lighter than the Wahoo ELEMNT ACE (209 g). This makes a real difference – not just on the scales, but also out on the road: less wobble over rough ground and a cleaner, more compact look on your cockpit.
On paper it looks good – but how does the Karoo actually perform when things get serious? When the rain falls sideways, your gloves are soaked and your heart rate’s through the roof? Time to leave the spec sheet behind and hit the road.
The Hammerhead Karoo in Review
With the battery charged and sensors paired, we headed out to put the Karoo through its paces on long rides, intense training sessions and daily commutes. We paid close attention to navigation, display quality, usability, battery life and training features – all under real-world conditions and with all devices running side by side.
As is often the case, the first impression comes from the screen – and the Hammerhead Karoo impresses right away. Despite being the smallest display in this test, it has the sharpest image, which is down to the high pixel density. The colours are vivid, contrast is strong and the brightness sensor reacts quickly to changing light. Whether you’re riding through a dark forest or under the blazing sun, the screen is easy to read. The viewing angles are excellent too – even from the side, the image remains crisp. While the Wahoo ELEMNT ACE just edges it in direct sunlight, overall the Karoo was the most legible display on test. That’s a huge plus when fast navigation decisions are needed.
But a brilliant screen isn’t much use if the battery doesn’t last. So we ran all three devices under the same conditions: navigation active, screen permanently on, auto-brightness enabled, two paired sensors and a connected smartphone. In this setup, the Hammerhead Karoo managed just under 15 hours – a solid result that’s easily enough for a long day in the saddle. There’s also a power-saving mode that can stretch that figure further by dimming the screen, reducing processor load and switching the display off when not in use – a smart feature. However, it’s worth noting that the larger Garmin and Wahoo units also have room for larger batteries. In our test, the Edge 1050 lasted around 20 hours and the ELEMNT ACE went the distance with 25 hours.
The Karoo’s user interface is modern and well thought-out. You can customise all your settings directly on the device itself – a real advantage over systems like Wahoo’s, which require a smartphone to adjust data fields. Making on-the-fly changes is quick and intuitive: just press and hold a data field, pick a new one, and you’re done.
Usability while riding is excellent. The touchscreen of the Hammerhead Karoo is precise and responsive, while the physical buttons offer reliable control in all conditions – even with gloves. The user interface feels modern and refined, with smooth animations and a clean layout that makes everything easy to understand. Menus, maps and widgets are informative and approachable, whether you’re a beginner or a power user. Of the three devices on test, we found the Karoo easiest to get on with. The Wahoo might be simpler overall, but lacks the same level of customisation. The Garmin offers the most settings and tweaks, but its pure touchscreen operation and slightly cluttered menus make it less intuitive than the Karoo.
Navigation is stable and reliable. GPS signal remained strong throughout our rides, even in wooded areas and busy city centres. If you stray from the planned route, the Karoo suggests reroutes based on your preferred terrain – road, gravel or trail. This usually works well, though some detours were a little overzealous. That’s a shared weakness with all the units on test. If you want to avoid unnecessary climbs or detours, it’s always worth double-checking the route manually.
The map view delivers everything you’d hope for. It’s clear and easy to follow, with well-visible turn instructions and color-highlighted cycle paths. Three preset zoom levels make it easy to get the right overview quickly, but you can also unlock continuous zoom for full control. If you’d rather not keep looking at the screen, note that the Hammerhead Karoo only offers voice guidance through paired Bluetooth headphones – otherwise, it simply alerts you with a buzzer.
Climbs ahead! Gradient sections are colour-coded on the map. However, the steepness isn’t shown directly on the route – instead, it appears either as a pop-up in Hill Climb mode or via a dedicated widget. These pop-ups, which also include turn instructions, are fairly big and can cover the map or data fields depending on your setup, though they can be disabled if preferred.
Using SRAM? Now it gets interesting. One of the Karoo’s standout features is its deep integration with the SRAM AXS ecosystem. The Karoo quickly and easily pairs with SRAM components like drivetrains, power meters and TyreWiz pressure sensors. Battery levels for each component are clearly displayed, and you can assign functions to the AXS shift buttons – not just for shifting, but also to control features on the Karoo itself.
However, if you’re using a Shimano Di2 drivetrain, things get tricky. Due to licensing restrictions, official support has been dropped. This means that you can’t connect your Di2 system to the Karoo straight out of the box. Fortunately, because the Karoo runs on Android, it supports sideloading external apps. That means Di2 functionality can still be added – and the wider Karoo community has developed plenty of extra tools, from music controls to fuelling reminders and custom widgets. Some of these are available directly, while others require a separate app store. If you like to customise your setup, there’s a lot of untapped potential here.
Compared to the Wahoo ELEMNT ACE and Garmin Edge 1050, the Hammerhead Karoo generation 3 stands out as a smaller, lighter option with an excellent display. Its user experience is intuitive without being limited, and it offers a high level of functionality and flexibility. The ability to add third-party apps opens up even more possibilities – especially for those already running SRAM AXS components on their bike.
Conclusion
The Hammerhead Karoo delivers a well-rounded package that’s hard to beat. Its standout display works brilliantly in all lighting conditions, the interface is clean and customisable, and the combination of touchscreen and button control makes for smooth, intuitive operation. Add to that the ability to run external apps, and the Karoo becomes a real all-rounder. If you don’t need a huge display and can live with slightly shorter battery life compared to Garmin or Wahoo, you’re getting a device that nails it on features, usability and performance. Especially if you’re riding with SRAM AXS.
You can get an overview of this comparison review here: Three High-End GPS Bike Computers on Test – Garmin Edge 1050, Wahoo ELEMNT ACE and Hammerhead Karoo go head-to-head
All GPS bike computers in review:
Hammerhead Karoo | Garmin Edge 1050 | Wahoo ELEMNT ACE
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Words: Jan Richter Photos: Jan Richter