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The Hammerhead Karoo 2 has an improved, compact design with a large enough 3.2inch (82mm) screen for viewing lots of data fields as well as its beautiful map in detail. The device is packed with great features such as a 'live strava segment' overlay, it's super responsive and has excellent navigational capabilities for both planned routes and out-in-the-wild spontaneous ones. There are also plenty of performance metrics, enough that WorldTour team Israel Start-Up Nation use the device.
Dave reviewed the original Karoo back in 2018 and thought it was excellent. The Karoo 2 comes with increased storage, from 16Gb to an impressive 32Gb, added dual Bluetooth Smart chipsets and an upgraded quad-core processor with 2Gb of RAM, for a faster and responsive device that's also capable of handling the regular software updates that Hammerhead installs to continuously improve and introduce new features with.
It runs on an upgraded Android 8 operating system that can be paired to iOS or Android smartphones for notifications mid-ride. You can turn messages, calls, voicemail and other apps on and off.
Audio alerts are now included with turn-by-turn notifications. You can set it so the device also beeps for upcoming intervals in workout mode, as vehicles are approaching when paired with the Garmin Varia, as well as for Strava live segments.
There's also a slot for installing a SIM card behind the circular cover round the back. This enables LiveTracking and can be used for WiFi tasks such as syncing rides and receiving notifications.
The Karoo 2 is smaller than its predecessor, measuring 60.3mm wide and 100.6mm tall, and weighing in at 132g. (Down from 98 x 72 x 28mm and 168g.)
The display is a very good size for viewing the data fields and maps. It is finished with a Dragontrail scratch-resistant screen for some decent defence, and the high definition full colour display has also been treated to reduce glare. It's clear and easy to read as you're riding – only on the brightest days have I had to notch up the brightness a little (and sacrifice a bit of battery life).
The touchscreen responds incredibly well in the dry. It feels much more like operating a smartphone than a cycling computer. In the rain it's not quite as effective, but still very much usable. There are also buttons on each side (four in total) which help when operating if you do run into difficulty when it gets wet or with some gloves.
The USB-C port is IP67 rated waterproof. It's proved to withstand prolonged periods of rain, but as the charging port isn't covered I've had some issues with dirt flicking up into it, particularly on muddy gravel rides – my bodge of using electrical tape does the trick, even if it's not the neatest looking solution.
The Karoo 2 has been developed with its own specific mounting system that works with standard round 31.8mm bars. The dual-locking system has a contact area that's designed to provide support for the device, and Hammerhead also claims its aerodynamic profile reduces drag.
Slotting the device in place, it gives a reassuring click and feels securely locked on this mount. There's also a hole for threading through the included lanyard for a touch of extra security along rougher terrain, but even for rides across the bumpier South Downs Way I had no concerns about the device falling off.
If you have a Garmin-style mount already set up across your bikes, you'll be pleased to know you can slide in the quarter-turn mounting adapter to the back of the Karoo 2 for using with your existing mounts.
You can create new profiles for the data fields you need for all the different types of riding you do, and there are lots of different layout options too. There's not been a metric or data field I've wanted that the Karoo 2 doesn't have the option to display.
The device can also show heart rate, power and elevation data in graph form. You can see a bar graph depicting the time in each heart rate or power training zone, for example. This graph also doesn't have to take up much of the screen space – you can choose a layout with six data fields above the graph.
If you have a route planned on a platform such as Strava, Komoot or Ride with GPS, or a friend has sent you a web link to one of theirs, it's really quick and easy to transfer onto the device by putting the URL website link into the Hammerhead dashboard 'import route' area. Or you can upload the original file in .gpx, .fit, .tcx, .kml, and .kmz formats here.
Another useful way of importing routes is by adding the Karoo Route Grab extension to your browser (such as Firefox and Chrome). By clicking on this installed icon it'll import the route on the webpage you are currently viewing to your Hammerhead Karoo dashboard, which is even quicker to do.
You can also build your own routes on the platform. It's quite basic compared with Strava or Komoot, but it does have some handy buttons such as 'reverse' to change the direction of your planned route and 'return' to go back along the same route you planned for the leg out. Usefully, you can also add a flag along the route to highlight where the coffee stop is or a campsite if you're going on a bikepacking trip.
Here on the Karoo dashboard you can also view your completed activities and sync with third party apps; for example, Strava for starred segments and Training Peaks for your upcoming seven days' worth of workouts. Other apps for ride and route syncing include Komoot, Ride with GPS and Xert.
On the routes page, as well as the name of the route, there's a preview map and details on the distance and elevation, to help you gauge if you're picking the one you had in mind.
It's also handy that you can change how these routes are ordered by newest (date created), gain (elevation), name, length and proximity. If, for example, you click 'length' it would show the longest route at the top, but by double-clicking on 'length' again it displays the shortest first.
If you don't have a route already planned, you can press the '+' in the top right corner and this allows you to create new routes. This is incredibly useful for making a new route when you're on the road itself, or away from home and without a laptop – as long as you have mobile data and you can set up a hotspot to the Karoo 2 or you have a sim inserted.
As the screen is so responsive it's easy to move the map about to create your desired route on-the-fly. You can zoom in and out to plot the points along the way, or type in a street name or post code.
For following the route, bright yellow lines and directional arrows point the way.
Turn information pops up on whatever page you're on, with details on the distance left until the turn, as well as an arrow indicating which direction.
The map detailing is fantastic, the navigational overlaps are handy and there are also the audio alerts to ensure you don't miss any turns.
If for some reason you do, it'll reroute you to the next point in the route you're following without going crazy.
The Karoo 2 has increased total internal storage of 32Gb (26Gb for maps) which is plenty for downloading additional offline maps for cycling holidays abroad. It's also super-easy to download these, as you can do so directly on the device itself.
Hammerhead has broken these down into individual countries so you're just downloading what you need. It's also quick to find the country as they are organised by the continent.
If connected with your Strava premium account, the Karoo 2 will automatically sync the segments that you've starred onto the device. You can enable and disable the segments on the device itself, and you can swipe between four active segment tabs as you ride along at one given time.
As you're riding you get a message about the segment(s) coming up, with the distance counting down – you can swipe away this notification.
The Karoo's live segment overlay is then displayed as you hit the segment. There's a lot of useful information going on here: you've got the distance covered in the segment, distance remaining in the segment, the elevation profile of the segment, elapsed time since beginning the segment, and some other symbols for tracking progress.
A yellow circle displays your position on the elevation profile and you can also see where you stand compared to other competitors, as well as your previous best and recent times.
There are different symbols such as a carrot representing the best effort recorded by a friend you follow on Strava, a wolf for the best time recorded by the nearest competitor behind you on the segment, as well as the KOM/QOM time, your personal best, recent best (last five attempts) and most recent effort.
Overall, I found this live segment overlay is great for gauging your effort and it's also super-motivating being able to track your time against different competitors – the visual format also makes it easier to see as you're digging deep in an effort.
The Karoo 2 has a USB-C slot for faster charging, getting the device from flat up to 30 per cent in 30 minutes Hammerhead claims. Hammerhead also estimates battery life as between 7 and over 14 hours depending on the features used and sensors hooked up during usage.
There's a 'battery save mode' in Quick Settings and Settings, which is a handy tool if you really need to conserve what's left.
Usually on rides I've found it lasts around 10-11 hours with all my power meter and heart rate sensors connected up, a route loaded, and flicking between screens.
Riding without a route loaded (but still with sensors) massively increases the life per charge, to around 13 hours.
I've been prompted about installing updates on the device a few times in the test period and continuing ahead with these hasn't affected battery life as far as I can tell.
Hammerhead has designed the system so it's easy not to accidentally delete your ride. You start the ride by clicking the lower right button and, once moving, press this button again to pause it. Once paused, to end the ride you switch over to the lower left button and then back over to the lower right button to confirm.
At the end of the ride you can rename it from 'morning ride' and you can toggle off or keep on the push button for rides to be immediately sent over to connected third party apps such as Strava and TrainingPeaks.
Priced at £359, the Hammerhead Karoo 2 is great value for this premium package. Its responsiveness, screen size and quality are matched by the genuinely useful features packed inside including the live Strava segment overlay and the graph depicting the time in each heart rate/power zone.
Hammerhead also has a 45-day risk-free trial. You'll get a free return and full refund if you don't get on. Although from my experience you'll never want to go back!
Garmin's Edge 1030 Plus is a chunky £161 more, although it does come with ClimbPro which is one of the most useful apps reviewer Liam has ever used.
That said, Hammerhead introduced its very own new Climber pop up overlay just last month which is helpful for gauging your effort up the climb and is also clear to read when digging deep. It has a countdown display with the distance and elevation of the climb remaining and also features a colour coded elevation profile which shows which sections are steeper or shallower.
The Garmin 830 is cheaper than the Karoo 2, by £9, but it has a smaller 2.6-inch screen (the Karoo 2's is 3.2in) and it's not as easy to use for on-the-fly navigation.
The recently released Wahoo Elemnt Bolt v2 is much cheaper at £250 (Mat did a first ride review which you can read here, and his full review will be coming soon). It has an improved screen and with the addition of Wahoo's Smart Navigation functionality you can select destinations directly on the device, but it doesn't have a touchscreen so the on-device navigation is slow.
Overall, the Karoo 2 performs brilliantly for both multi-day bikepacking trips and all-out interval sessions with some Strava segment hunting. Its slimmer than the previous design, powerful as well as responsive, and so simple to use.
The device syncs with the dashboard effortlessly for planned routes, and it's so great being able to make spontaneous routes – as detailed or basic as you please – directly on the device while out on the road (or gravel).
It's reliable and an ideal choice if you want all your usual performance metrics along with impressive and trustworthy navigational support.
Super-responsive and easy to use – a go-to for its navigation and training capabilities combined
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road.cc test report
Make and model: Hammerhead Karoo 2
Size tested: One Size
Tell us what the product is for and who it's aimed at. What do the manufacturers say about it? How does that compare to your own feelings about it?
Hammerhead says: 'Karoo 2 is designed to put your cycling experience first. Powerful features make it simple for cyclists to do structured workouts, follow routes, connect to Strava and other third parties, and get the most out of every ride."
Tell us some more about the technical aspects of the product?
Dragontrail glass panel with Acid Etched matte finish
High resolution 3.2" display panel with 16.7 million colours supported
responsive touchscreen, with droplet rejection
Fully controllable with buttons
Overmoulded shock-reducing bumper
Waterproof SIM card cover
Water and dust proof to IP67 rating
2500 mAh high capacity battery
12 hours of ride time
UBS-C with fast charging
Waterproof USB-C port
Quad core 1.1Ghz, CPU with 2gb of RAM
32 gb of storage (26gb for maps)
3-axis accelerometer, magnetometer and gyroscope
Hammerhead Mounting System (patent pending)
Standard ANT+ and Bluetooth Smart sensor support
Varia Radar support
Shimano Di2 support
Strava live segments
Upload activity to 3rd party services
TrainingPeaks workout integration
Sync routes from 3rd parties
The Garmin 1030 Plus is a touch lighter at 126g.
Tell us how the product performed overall when used for its designed purpose
Fantastic navigational functionality and great for following your performance metrics as you ride. The high definition touchscreen clearly shows your data and map detailing, and the device is a delight to use thanks to its incredible responsiveness.
Tell us what you particularly liked about the product
The incredibly responsive touchscreen and how that made on-the-fly routing so quick and easy.
Tell us what you particularly disliked about the product
Lack of charging port cover as dirt can get in.
How does the price compare to that of similar products in the market, including ones recently tested on road.cc?
The Karoo 2 is £161 less than Garmin's 1030 Plus, but the Wahoo Elemnt Bolt V2 is £250, which makes it £109 less than the Karoo 2.
Did you enjoy using the product? Yes
Would you consider buying the product? Yes
Would you recommend the product to a friend? Yes
Use this box to explain your overall score
Absolutely great to use for both multi-day bikepacking trips and all-out interval sessions with some Strava segment hunting. The price may seem quite high, but for the spec it's well worth it.
About the tester
I usually ride: Road bike My best bike is:
I've been riding for: 10-20 years I ride: Every day I would class myself as: Expert
I regularly do the following types of riding: road racing, cyclo cross, commuting, touring, club rides, sportives, general fitness riding, Gravel riding, indoor turbo and rollers, track
Anna has been hooked on bikes ever since her youthful beginnings at Hillingdon Cycle Circuit. As an avid road and track racer, she reached the heady heights of a ProCyclingStats profile before leaving for university. Having now completed an MA in Multimedia Journalism, she’s hoping to add some (more successful) results. Although her greatest wish is for the broader acceptance of wearing funky cycling socks over the top of leg warmers.