Let’s face it: despite costing the same as a decent smartphone, modern bike computers often resemble machines from the early 2000s. Yes, they are designed for a very specific job, and (usually) do it very well: collect and display cycling-specific data in real time as you ride, as well as storing this data for later analysis.
But with all the money we spend on them, shouldn’t they be more refined? That might have been part of the thinking that went through the minds of the boys and girls at Hammerhead when they designed the Karoo: Make the user experience feel smarter, faster and more satisfying. They achieved this simply by not reinventing the wheel: They built a powerful piece of hardware and installed an Android-based OS.
With the best display on the market, an excellent touch screen and the best on-ride user interface I have ever used, the Karoo 2 is, in my opinion, the finest computer on the market. It would easily be more expensive if it had the logo of “you know who” on it.
Hammerhead took a big step in a direction that its competitors failed to explore and made a significant impact on the market. Not only did it catch the eye of cyclists who love technology, but it also caught the eye of a major player that has been growing steadily over the past years: SRAM. The giant from the components sector acquired Hammerhead in 2021 and integrated it as one of its brands.
In the box – Basic accessories plus quarter-turn mount adapter
The Karoo 2 comes in a very stylish box, reminiscent of a smartphone case. It contains the bike computer, the original Karoo 2 mount, a quarter turn adapter (Garmin standard), a 2.5mm Allen wrench for attaching the mount, a tether, a USB-C charging cable and a quick start guide.
The Karoo mount might feel a little strange at first, but you soon get used to it. It felt like it held the computer much better than the most common quarter-turn mount I’ve used with computers from other brands, but I haven’t really been able to test that. I used the mount for a few weeks before using the adapter to switch to the Sram quarter mount. No problems either. The adapter also a very fit hold. The buttons on the side are large and very easy to reach. Buttons on the same side are not too close together, which is also positive.
The computer weighs 131g and is a bit thick. Much smaller than the first version of the Karoo though, so it was a good improvement. It also has a very nice design and a USB-C charging port.
Display – “You had me at scrolling”
Within seconds of switching on the device, you’ll have the proof that the screen is unparalleled. The Karoo 2 greets you with images and video, welcoming you to “a new kind of head unit”. This alone is a feat that none of its competitors can match. Touching the screen and swiping left and right makes it feel like you’re using a smartphone. Hammerhead has combined a powerful 3.2″ scratch-resistant screen with Android to create a very pleasant user experience. The touchscreen does not seem to be affected by water at all, and I never had to lock the screen to avoid unwanted inputs. It is also very easy to use with gloves, but if your gloves are not touchscreen friendly , you can also use the buttons for most ‘on ride’ actions.
The data fields can be personalized to your needs, combining raw data with graphics that change color according to your heart rate or power zones. This makes it much easier to hit a zone 2 ride, for example. You can personalize your profiles and the screen and data fields of each profile, including maps, graphics, training data and so on. I like a data screen with data and graphics combined plus a map screen with some basic data next to it. Last, I add an “Averages” screen to check periodically during the ride.
IMPORTANT: As to this moment, the user interface is only available in English.
The turn-by-turn navigation shows a clever and small turn indicator at the bottom of each screen, so I only used the map page when I really needed it. While some people prefer a big ‘TURN’ overlay, I really liked the little hint. As a road cyclist, unless you’re backpacking, you usually know where you’re going and use the navigation mainly to show you the route you’re taking that day. However, if you are navigating through new territory, the map page will be more useful. It is very detailed and has very good colours and contrast.
At the bottom of the screen, three categories of overlays can be quickly swiped up and down: Strava segments, messages and climber function. The overlays are a much better way of displaying information that you only want to see temporarily than changing pages (which many other devices do). You can swipe the overlays up to see their full content or keep them at “half size” if what’s being displayed is enough. If you swipe them down, they will hide back.
Ride and Navigation – Smart enough to guess where you’re going.
No, the Karoo 2 does not integrates the lates AI available into its system, although if that becomes a thing in the future, Hammerhead will probably be the first to achieve it. The subtitle of this section is a reference to the fact that Karoo 2‘s climber function does not require a defined route to calculate the climbs. That can be a gamechanger in many group rides. If the device detects a climb in the vicinity, the Climb Overlay will be available. If you take a turn indicating you are not going for it, it will disappear. You can also swipe it down if you don’t need it, leave it as a ‘half-size’ (which is what I do), or swipe it up to fill the page with extra climbing data. If you have a route loaded, Hammerhead will keep track of all your climbs and compare them live, so you can also use the climber function overlay to measure your performance throughout the training. It will also show you a full overview of all climbs, informing you how many you did, how many you still have and where you are at.
The Android-based software offers constant updates and has excellent connectivity with other apps such as Strava, Komoot and Training Peaks. Like other top-of-the-market computers, the Karoo 2 can operate independently of a smartphone and connects to your Wi-Fi to import and export data. If you are on a trip, you can also use the Karoo 2’s SIM CARD port to connect to the Internet. Navigation, of course, works with the GPS connection and can follow imported routes as well as navigate you back to your starting point if you have gone off exploring.
As expected, the route will be updated if you need to re-route or if you choose to navigate back to the start. I tested with routes from Komoot, Strava and files exported from Garmin Connect and had no problems loading the routes.
Importing Training Peaks workouts is easy once connected. The computer also suggests planned workouts, which are automatically displayed in the menu. The workout page provides graphics and all the data you need to complete the workout. Of course, this also depends on the gear you have connected. I connected the Karoo 2 to my Favero Duo Powermeter pedals and my heart rate monitor from another brand. Connecting to my Sram eTap AXS Rival groupset was also easy. The device displays relevant information such as the battery status of the derailleurs and the shifting data. I also tested the computer for a few weeks with a Varia Radar and the connection and use was absolutely smooth.
Conclusion – A lot of tech for a very fair price
We cyclists often have good reason to complain about the price of our hobby or profession, but I think it would be very unlikely to find anyone complaining about the price of the Karoo 2. This computer has all the functionality you would hope for, plus some unique advantages such as its great screen and asy smartphone-like handling. If you’ve been using another brand for a long time, it may feel different at first, but the learning curve is certainly faster than with any other manufacturer. I for example once deleted a fairly difficult training ride. I was able to recover the ride file by switching the computer to developer mode (it is Android after all right?). Minutes later, I manually uploaded the ride to Training Peaks and Strava. Developer mode is a little outside the scope of this product review, but if you need a tip, don’t hesitate to write to us. Furthermore, until Zwift Companion required Android 9, some users have installed the app directly on their Karoos 2. Can you imagine that happening on a competitor’s device?
The Karoo 2 has a lot of technology at a very good price. It has a great display and a very pleasant user experience. It is also very reliable and has given me no problems on the road, which is crucial. I do not see myself using another device in the near future.