Hammerhead Karoo 2 Review
So good to look at, so full of features and with the best screen any lycra-wearer can ever want to own but its battery life is ‘only’ good, not ‘great’; that’s the Hammerhead Karoo 2 and this is my review of it, warts and all.
Hammerhead’s new performance bikenav ticked all the boxes that weren’t ticked in the original version and then went back over the boxes that were already ticked and added some extra-thick, super-sized green ticks. The new Karoo 2 is now more compact, faster, has an even better screen and a wholly new audio beeper! The onboard SIM can now be 4G and some of you will love the USB-B charging and beefed-up storage capacity for maps, there is some seriously good tech inside.
Garmin Edge 1030 Plus will remain the King of the obscure feature list but, you know what? Hammerhead’s Karoo 2 probably has all the features you need and want plus quite a lot of other ones too…just in case. Even better; Karoo 2 packs that impressive feature list into a beautifully designed shell with the very best screen and the most awesome software interface.
That’s why the Karoo 2 is a genuine Garmin-beater, it’s simply a joy to use.
Karoo vs ELEMNT
It’s best to first compare Hammerhead’s Karoo 2 to a Wahoo ELEMNT Bike computer as both rely on the complex stuff like training plans, structured workouts and analysis being accomplished via a 3rd party platform. In my opinion, that’s a great model. Where Wahoo ELEMNT and Hammerhead Karoo differ is that Hammerhead wins with good web-based route functionality whereas Wahoo’s app wins as is has the simple reporting that Hammerhead lacks, furthermore, the ELEMNT app is where the Wahoo ELEMNT is configured and that keeps the ELEMNT’s menus on the bike computer nicely simple.
Karoo vs EDGE
I’ve used Garmin Edge and Wahoo ELEMNT bike computers for years and I’ve cycled with the Hammerhead Karoo 2 for thousands of miles in preparation for this review. They are all accurate enough and they all connect to the external sensors and bike trainers that everyone uses, sadly they’re all relatively expensive. Yet the Hammerhead Karoo and Garmin Edge surge ahead of the ELEMNT when it comes to quality mapping and turn-by-turn (re-)routing.
Both Garmin Edge and Hammerhead Karoo undertake all the settings on the bike computer and that’s great when you need to make a change during your ride but, as the months go by and the new features pile up, that approach adds ever-increasing complexity to the interface on your handlebars.
Because Wahoo has offloaded complexity to its app, it means they should always be able to deliver a highly usable bike computer experience. Still considering usability, Hammerhead beats the Garmin Edge every time…the usability of the Garmin Edge is like a car crash, with 3 different interfaces and menus scrambled together in what can often best be described as a visual mess of sprawling blandness with an occasional moment of genius.
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Hammerhead Karoo 2 Review Summary
I’ve put the review highlights into this summary of my time with the Hammerhead Karoo 2, please scroll further down for plenty more detail. Buying via the Hammerhead banners supports the work here with a small commission which keeps this site firing on all cylinders and keeps giving you the free content, thank you.
Hammerhead Karoo 2 Review
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Price - 90%90%
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Apparent Accuracy - 95%95%
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Build Quality & Design - 95%95%
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Features, Including App - 90%90%
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Openness & Compatability - 90%90%
Karoo 2 | Verdict
I love the Karoo 2 and can recommend it as easily as I can recommend a Wahoo ELEMNT or top-end Garmin Edge to support my rides and routes.
The Karoo 2’s screen can be customised to show traditional ride data or richer, prettier charts and colour-coded, ride information. Special Strava & Varia Radar functionality adds even more competency to what you can see and, of course, you can link to your favourite bike sensors and sync both ways with Training Peaks.
If my needs involved complex on-device route creation or to frequently follow complex, customised indoor trainer plans then my positive opinion would change a little. Those kinds of scenarios either require you side-load a 3rd party Android app or manage the complexity elsewhere on (eg) Training Peaks and Strava.
For 95% of riders, Karoo will do a great job.

Pros
- Superior hardware all around, market-leading screen
- Superior interface experience
- Great performance features
- Side-loaded apps give the likelihood that any missing features can be filled in style from existing 3rd party apps
- Good navigation package with onboard maps and (re-)routing by address
- Supports innovative ways to curate and load routes from multiple sources
- Synchronises and executes complex, power-based, indoor training plans
- Supports all commonly used 3rd party sensors including Di2, FE-C and Varia
- Several types of smartphone notifications can be configured
- A SIM card means you can leave your phone at home.
Cons
- PM calibration is somewhat hidden away (annoying)
- Like Wahoo, Hammerhead expects you to perform your post-ride analysis elsewhere (Strava, TP, etc). Solution: side-load an app!
- Sensors not active for a few minutes are ignored. Post coffee, that’s annoying
- It’s expensive but $200 less so than an Edge 1030+ which isn’t worth the extra
- I get just over 10 hours of battery life, I’d like more but can live with that
- K2’s screen is a tad too small for some sideloaded apps. otherwise perfect.
- Complex on-device route creation isn’t yet possible unless you side-load another app (side load an app instead)
- No trainer workout customisation pages (niche, sideload an app instead).
Hammerhead Karoo 2 Specifications
No review is complete without an exciting list of specifications, so here is the full splendour of those for the Hammerhead Karoo 2.
It has a bright screen, updates over WiFi/cellular and is effectively a smartphone running custom apps on Android 8.0 ‘Oreo’ (2017)
- Dimensions: 98 x 72 x 28 mm (3.8″ x 2.8″ x 1.1″)
- Weight: 131g + 36g (mount)
- Screen: 1.1mm Corning Gorilla Glass cover, 3.2″ diagonal (2.10″ x 2.80″ or 53.28 x 71.04mm), auto backlight
- Interface: 4-buttons and/or capacitive touchscreen
- Resolution : 400x800px @ 292ppi
- Storage: 32GB
- GNSS: GPS + GLONASS
- Onboard sensors: Barometric Altimeter, ambient temperature, gyroscope, magnetometer, accelerometer
- Battery Life: 3200mAh gives up to 14 hours, realistically it’s more like 10 – with navigation eating further into that. 3 hours to recharge
- BLE/ANT+ Sensors: HR, FE-C, cadence, speed, power, Di2 (shifting and buttons), Varia Radar
- Charge Port: USB-C, IP67
- GSM Cellular: SIM slot 2G, 3G, 4G (or pair to your phone for notifications)
- Platforms: Training Peaks, Strava, Komoot, RwGPS, Xert
Full specifications: hammerhead.io
Hammerhead Karoo As a BikeNav
Garmin has the most in-ride navigational features yet, in my opinion, the straightforward navigational experience with Karoo 2 is superior. It sweetly ticks all my boxes. If you have more complex guidance needs then Karoo often does not address them – for example navigating to the start of a route.
You’re either buying this Karoo 2 because you want something pretty+competent or you want a market-leading navigational experience. Let’s assume it’s the latter and here are some of the many navigational highlights you can expect.
Creating & Curating a Route Library
I’ve liked and loved Hammerhead’s online route platform for a couple of years now. It’s a given that you can do the basics like uploading a FIT file or linking and syncing routes from Strava/RwGPS. However, you can do other cool stuff, like this
- Cut and paste a URL that displays a route eg from Google Maps!
- Use Hammerhead’s Chrome Route Grab extension to, err, grab routes…super quickly. Like, with ONE click.
- Simply share your routes with friends with any media whilst simultaneously understanding which route you are using from which source platform
- Online route creation HAS been improved over the last 18 months and, for me, it now creates good London-centric routes but periodically misses when some commonly-used paths are available. Like other platforms, you can choose, maps, surface type and see the elevation profile.
Hammerhead offers a rich navigational experience which ranges from grabbing routes from Google Maps or automatically syncing them from Strava/Komoot/RwGPS. I like the online route creation tool and the quality of route choice HAS improved since first implemented on the first Karoo and, at least where I live, I would now say it create mostly correct routes. Hammerhead lets you curate your own online route library which is a joy to visually manage and easily share with friends and one other aspect that stands out is the instantaneous nature of it all if you change a route or Hammerhead’s platform or even on Strava then, almost instantly, you’ll find it simply appears on your Karoo 2 via WiFi.
Following a route
Street names and turn-by-turn instructions are only part of the in-ride experience with Karoo2. As this short video shows, re-routing and coloured chevrons give you an instant understanding of your status on the route.
That said it’s not perfect. Hammerhead is trying to ‘keep things simple‘ and some, more complete, on-device features don’t exist – for example, you CAN navigate to a specific zip/postcode on the Karoo 2 but you can’t create a more complex route via a second post/zip code, although you can add waypoints. How often have I wanted to do that?…never.
Similarly, if you want to create a highly tailored navigation screen then Karoo 2 does not have many weird and wonderful navigation-specific metrics that you will find on a Garmin Edge 820.
The solution is to side-load your favourite Android navigation app, like RwGPS. Of course, if you choose to use RwGPS or STRAVA on your Karoo then you also get popularity routing and heatmap driven routing respectively 😉 Sweet !
If you want multiple pieces of obscure navigation functionality then the ONLY solutions will ONLY EVER be either Garmin or Android (Karoo!)
Karoo 2 As a Performance Bike Computer
Karoo 2 is a great performance bike computer. This doesn’t mean you’ll be using it in the Tdf it just means that it is very well designed to be able to support anyone striving to do better. So it definitely gives you all the common performance metrics that you need from power meters, speed-cadence sensors and heart rate monitors. Normalized power, upcoming hill profile, fancy dials and displays galore…you have zero need to worry about ANY of that. In fact, you will be excited that there are new and innovative ways to display some of your in-ride data. Ways that you have never seen on your mates’ Garmins.
I’d count Strava Live Segments as a ‘performance’ feature and the Karoo 2 beats Garmin on this one with great on-screen graphics that support your PR attempts. Here is a detailed comparison of the Strava Live Segments offerings of all the major vendors – Karoo wins BTW. If you don’t want to click that link, here are 4 pretty, animated images!
If you want the speed and certainty of Di2 shifting then Karoo 2 gives you all the key goodies: the ability to change Di2 shifting profile; support for hood-top Di2 buttons and just in case you’re not sure what gear you are in you can visually display your gear (below). There are other Di2 metrics like shift count but none are written to the FIT file.
If you have a power meter then advanced dynamics are supported for display and recording namely LR Balance, Pedal Smoothness and Torque Effectiveness (PP, PCO)
Indoor Workouts with a Smart Trainer
Karoo 2 quickly syncs to 3rd party training plans and further supports custom workouts that you might create on, or load to, Training Peaks/Xert. These workouts control modern smart trainers using ANT+ FE-C. The only downside here is that you can’t store your favourite workouts on your Karoo, instead, you have to, for example, store them on TP and sync from there. Hammerhead is working to resolve that minor issue.
The structured workout execution screen is ‘fixed’ at the time of writing, meaning you can’t change what’s displayed. So for now, you still see the target power profile, actual power and you have the ability to pause or skip through phases of the workout. I’m less concerned about trusting Hammerhead to add the ability to change the screen than I am that you can only manually move between workout phases by pressing a tiny part of the screen area. My experience from using a Wahoo ELEMNT for indoor training is that it is very much easier to press a big knobbly button when you are fatigued & sweating profusely.
Your completed workouts are easily synchronised to analysis platforms like Training Peaks and social platforms like Strava. But before that happens, your workout summary screen adds some nice touches by enabling you to name your workout before choosing which platforms to synchronise with.
The Karoo As a Smart, Bike Computer for everyone else
By ‘smart’ you might mean properly handling and presenting traffic alerts from a Garmin Varia Rader then, yep, it does that REALLY well. If smart means handling Di2 then that’s pretty awesome too and you can even choose the Di2 shifting profile from with the Karoo itself!
But smart doesn’t end there. Oh no. As Karoo 2 is essentially an Android smartphone you can load up smartphone apps to work alongside the usual Karoo interface, you can load Xert, RwGPS to Zwift or just about any app.
Not everyone takes a phone with them when they ride. I don’t! If I put my Sim into the Karoo then my loved one could track me and I could install Whatsapp to use if I needed bringing home and Spotify to listen while I wait.
Hammerhead Karoo 2 Accuracy Review
It’s Accurate
I used to spend a day putting together GPS comparison imagery and writing it up. For most bike computers that is wasted time and bloats the review size, so I’m now investing the hour+ of analysis with no write-up. Please add a Supporter-request below if you really want to see more.
With GLONASS enabled, the Karoo 2 is as accurate as the best bike computers.
Very many Zwifters & London-based cyclists will recognise Box Hill, this image shows a perfect track from the Karoo 2 going up it, which is indicative of almost all other rides. Other devices are sometimes slightly worse than this…not the Karoo.

Whilst Karoo 2’s GNSS is accurate, I have two minor concerns. There are very occasional blips of, say, once in 50km where the track exceeds the +/5m accuracy bounds for a second or so. Secondly, the Karoo Dashboard seems to show a jagged track, I double-checked what was recorded into the FIT file and all was good so I assume the Karoo dashboard simply displays less granular data than the per-second data that is recorded.
Unusual & Notable Extras
- Karoo 2 has a good and novel mounting system, handily it has an adapter for Garmin mounts too 😉
- All good bike computers include a lanyard to prevent accidental damage, Karoo has one
- There is a seemingly exhaustive choice of screen layouts that combine numeric data, dials and charts of all kinds. The metrics that can be chosen for the screens are wide-ranging too and one of the interesting quirks is that when you are setting up the screens, dynamic and changing data is displayed. It’s a nice touch and better help you visualise the end result.
- Many visual elements relating to the display on your ride data are superior to anything else on the market. There is aesthetic beauty to the design, layout and animation of everything from a heart rate zone display to the progress vs the KOM on your active STRAVA segment. This is all boosted further by the best screen resolution on the market.
- You can change the order of your paired sensors which, theoretically, means that your power meter can be quickly available to pair or a certain speed sensor is given priority over others.
- In its standard form, Karoo 2 supports workouts from Xert. However, you can also side-load the Xert Android app for the full Xert workout experience on your Karoo
- Not happy with the breadth of navigational features? Then why not simply sideload the entire RwGPS Android app and use its navigational features? This approach with 3rd party android apps can bypass ANY minor navigation shortcoming.
Sideloading Apps to a Karoo 2
Sideloading an app is not straightforward but worth a go. You need developer access to the Karoo and sometimes the ‘standard’ instructions for connecting to a PC don’t work as MTP support might interfere. Furthermore, some apps, like Strava, need root/playstore level access.
Help Forum: Karoo Users !
That said it took me 15 minutes to install Xert and Ride with GPS, the former to execute structured workouts on a Kickr and the latter to add different routing features. If you add strava you will get half-decent analysis features on your Karoo. Garmin Edge doesn’t do that, although the Connect app does.
This is really clever stuff, the bottom line though is that many of these apps are designed for a slightly larger screen and look and work better on the Karoo 1 (and smartphones).
That said, you should be able to get all these to work perfectly well:
- Ride with GPS – for different routing features
- Xert EBC – to execute complex plans and control your Kickr
- Strava – post workout Strava fun.
- Spotify – with earbuds
- Whatsapp – for instant messaging. I’m unsure if the speaker in earbuds will work for voice calls
In a Nutshell – Hammerhead Karoo 2 Review
There is no such thing as the best bike computer for everyone. Wahoo ELEMNT ROAM/BOLT, Garmin Edge 530/830/1030+ and Hammerhead Karoo 2 each have subtle superiorities over the competitors.
In one sense, Hammerhead’s open platform approach is like Wahoo’s and links to 3rd party analysis tools, complex route creation tools and social sites. Unlike Wahoo, Hammerhead’s approach is to keep all the device management on the Karoo. That choice has its pros and cons and there is no right or wrong answer for everyone.
However, Hammerhead has a few extremely powerful ways to address the shortcomings that inevitably exist on a small company’s platform. The Karoo 2 is a smartphone and so if you want more analysis, more complex route creation/following or more from structured workouts then, for example, you can load the Strava, RwGPS and Xert apps on to the Karoo. No-one else can do that and Garmin and Wahoo NEVER will be able to do that. Android compatibility is the sole reason why Hammerhead might take over the cycling world…or not!
Furthermore, the Karoo 2 is a properly specified piece of hardware, in many ways superior to the iPhone X and probably faster than every other dedicated bike computer, at least it feels that way to me. It runs very smoothly and really powers the beauty of its market-leading screen. Even better than that, Hammerhead’s interface designers have crafted something beautiful to delight your eye.
Karoo 2 is the real deal.
Perhaps the only drawback that can’t be resolved or worked around is the burgeoning array of options on the Karoo 2 itself. Wahoo cleverly keeps those on the companion app and that makes the in-ride experience for Wahoo super-slick. But Wahoo will never rival the looks of the Karoo 2. Never.
Would I change from Wahoo to Hammerhead? Well, I’ve used it as my MAIN & ONLY BIKE COMPUTER for the last two months. You can take that as a recommendation that you are about to make a sensible decision 😉

Hammerhead Karoo 2 Discount, Price, Availability, Review Summary
The price is right for a high-quality, mid-sized touchscreen bike navigation computer.
A discount for the Hammerhead Karoo 2 is unlikely until late 2021, Hammerhead simply can’t keep up with demand and has no need to lower the price. There have been shortages and waits for units so please check the current status (links). Proprietary mount and lanyard are included and the Garmin mount was included for pre-order (probably now extra)
