[2024] Karoo 3 Review ❌14 cons ❌, ✔️14 Pros✔️ Hammerhead’s Third Generation GPS Bike Computer

Hammerhead Karoo 3 review third generation heroHammerhead Karoo 3 Review

Sorry Garmin. Karoo 3 is perhaps the best bike computer for large numbers of riders but certainly not the most featured.

The third generation Karoo is super-easy on the eye and with monthly updates is packed full of even more features than its predecessor at launch, the 15-hour battery life and improved colour touchscreen offer more than most lycra-lovers will ever dream of for every kind of cycling, that’s the Hammerhead Karoo 3 and this is my review of it, warts and all.

Hammerhead’s new performance bikenav is now a formidable alternative for any Garmin or Wahoo lover. Whether you want guidance over gravel or pacing and performance on the road, Karoo has a beautifully designed interface that works sleekly and competently. In my opinion, it’s better than any Garmin Edge and different to every Wahoo.

Hammerhead Karoo 3 Review Summary

I’ve put the review highlights into this summary of my time with the Hammerhead Karoo 3, please scroll down for plenty more detail. Buying via the link supports the work here with a small commission, thank you.

FYI: Media Loaner, unpaid

Verdict: ⭐⭐⭐⭐ - Probably the best performance bike navigation computer.

Hammerhead Karoo 3 Review Summary

There is no such thing as the best bike computer for everyone. Wahoo ELEMNT ROAM/Wahoo Elemnt BOLT, Garmin Edge 540/840/1040+ and Hammerhead Karoo 3 each have subtle superiorities over each other.

In one sense, Hammerhead’s open platform approach is like Wahoo’s with 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 and double down on the navigation experience. That choice has pros and cons with no single right or wrong answer for everyone.

Furthermore, the Karoo 3 is a properly specified piece of hardware, probably faster and smoother than every other dedicated bike computer, at least it feels that way to me. It runs very smoothly and easily powers the beauty of its market-leading screen. Even better than that, Hammerhead’s interface designers have crafted something beautiful to the eye making navigation easy and intuitive.

Battery life is improved by 30% with a faster charge time and, whilst the device/screen is essentially the same size, the toughness and visibility are improved. The cycling-specific maps are boosted by free Heamaps from Suunto.

Every kind of riding support you need is covered by Karoo, ranging from following a route from RwGPS or Strava whilst on holiday to chasing Strava Live Segment PRs on your TT bike. If leading-edge, adaptive power training with Xert is your thing or if that lung-busting FTP-booster session from TrainingPeaks is more your cup of tea, all will be good in your indoor pain cave.  Naturally, you can sync and follow your TrainerRoad workouts as well.

Maybe you have a bog-standard heart rate strap or rely on an advanced Garmin Varia Radar taillight for safety or maybe you have a pressing need to display Core Body Temperature or SRAM AXS gear info; you guessed it. All is good.

Karoo 3 is the real deal.

Hammerhead has shortcomings but it’s based on an Android phone and that tech offers unique ways to overcome them. No one else can do that including Garmin and Wahoo. Android compatibility is the sole reason why Hammerhead might take over the cycling world…or not!

Perhaps the only drawback that cannot be easily resolved is the ever-increasing array of options and features on the Karoo 3. The more complexity added, the higher the danger Karoo’s menus have of becoming a complex mess like those on a Garmin Edge. Wahoo Fitness by contrast, cleverly keeps a lot of its feature padding on the companion app, making its in-ride experience super-slick. But Wahoo will never rival the looks of the Karoo’s display. Never.

Recommendation: Yes, I can recommend it. Please ask below if you are concerned about specific features you need.


  • Frequent feature updates
  • Smartphone quality screen
  • All-day battery life but…
  • Taller screen, suited to following route-up directions
  • Workouts and plans via Training Peaks, XERT, Trainer Road & FIT
  • Re-routable, TBT Routes via Komoot, RwGPS and Strava
  • Navigable POIs from Apple/Google Maps
  • Strava Live Segments (Summit only)
  • Hill climb doesn’t require a route
  • Good screen size compared to overall size (minimal bezels)
  • Highly usable.
  • Highly pretty.
  • Excellent for navigation
  • Good for performance


  • Routes don’t sync automatically unlike structured workouts
  • No automatic power meter calibration prompt, manual only
  • No drink and fuel alerts
  • Physiology metrics via the Suunto app, are not live
  • Garmin battery life is significantly better
  • Di2 support only via 3rd party Ki2 app
  • No way to display wind direction in a data field
  • Side-loading apps is non-trivial
  • Heatmap data seems outdated?
  • Re-routing only to the nearest route point is not the best option
  • CLIMBER cannot customise hill parameters
  • Elevation data is occasionally incorrect, seems reliant on companion app.
  • Elevation calibration by favourite locations (home) is missing
  • Long boot time


Hammerhead Karoo – is it For You?

SRAM/Hammerhead will find the most success with customers looking for the best solution for rich navigation. Next would be people who want a cool-looking piece of tech, perhaps to match their iPhone or eBike. A third major grouping will be some Performance Cyclists looking to avoid the complexity and usability issues of a feature-full Garmin. Finally, Karoo will come packaged, almost as a freebie, with a new SRAM AXS groupset offering deep integration with its components.

If you want a streamlined bike tech experience maybe you go for Wahoo but if, like me, you are a tech reviewer who reviews other weird bits of tech then you have to buy a Garmin as that is the only product that is near-guaranteed to work with such tech at launch.

For most riders, the purchase decision comes down to usability vs features vs price vs aesthetics vs battery life. Karoo wins on most of those but tech reviewers tend to focus on the longest feature list and consumers also tend to buy a Garmin for its features on a just-in-case basis…but forget about usability. And you use a bike computer for every ride, right?

Hammerhead Karoo – What’s New?

This is a significant upgrade for Karoo compared to the launch of Karoo 2: the hardware is wholly new; new navigation and safety features are introduced via a smartphone companion app; deep SRAM AXS integration is introduced; and improvements are made to structured workouts

  • Improved workout support
    • TrainerRoad and Training Peaks workout integrations supported
    • Revamped and customizable workout player
    • Visibility of upcoming and past intervals
    • Visibility into in-ride COMPLIANCE of intervals.
    • Visual Bar or Numeric target guidance
    • Easily dismissible
  • Improved hardware
    • Better components – screen, battery, dual frequency GNSS/GPS chip
    • Gorilla Glass
    • Variable automatic screen brightness and brighter
    • New power/screen-off button
    • Loud beeper
    • Removal of onboard SIM.
    • New bosch pressure sensor (for altimeter)
    • slightly different case shape and buttons
  • New iOS/Android companion app (not for Karoo 2)
    • Live Tracking
    • Quick Navigation In-Ride – Send a GPS Point from Google Maps or Apple Maps to Karoo, navigate to it or save it as a Pin.
    • Route File & Workout Importing – Use the phone’s native features to share a Route or a Workout to Karoo via the Companion App.
  • SRAM AXS Integration
    • Detailed battery information – Karoo shows you the same detailed battery information about each component in your AXS system as the AXS App
    • Battery level alerts – also for non-SRAM sensors eg Stages
    • Controller configurations on Karoo
    • Automated AXS Sensor pairing – ‘just works’
    • AXS App low battery notifications, post-ride

Hammerhead Karoo – Compared To Wahoo ELEMNT and Garmin EDGE.

Garmin Edge 1040 will remain the King of the obscure feature list and Wahoo Roam 2 will remain the Queen of performance simplicity. But, you know what? Hammerhead’s Karoo 3 has key features implemented well plus quite a lot of other ones too…just in case. Even better; Karoo 3 packs its impressive feature list into a beautifully designed hardware shell with the best screen and best-designed software interface in the business.

That’s why the Karoo 3 is a genuine Garmin-killer, it’s simply a joy to use. It’s highly usable…and that’s what you’re buying a bike computer to do, right? Be used.

Wahoo Roam, Garmin Edge 540, Karoo 3, Magene, Stages M200
size Comparison: Wahoo Roam, Garmin Edge 540, Karoo 3, Magene, Stages L200

Comparison Hammerhead Karoo 3 vs Wahoo ELEMNT Roam 2

It’s best to first compare Hammerhead’s Karoo 3 to a Wahoo ELEMNT Roam 2 bike computer. Both have a similar approach to dealing with the complex stuff like training plans, structured workouts and analysis being accomplished via a 3rd party platform. That’s a great model.

Karoo has an excellent web-based route catalogue that links & syncs with 3rd parties, plus it allows advanced routes to be created and its companion app allows clever on-the-fly routing to points found on Google/Apple Maps.

Karoo and Wahoo each use a smartphone app for in-ride things like phone notifications and safety alerts. However, Wahoo’s app offers simple post-ride reporting. To get the same with Karoo, you link to a 3rd party app, the best one is Suunto’s.

Karoo 3 has superior on-device management. Everything you want to tinker and configure is on the Karoo. Contrast that to Wahoo where the company is transitioning from having most of the configuration on the app to having more on the ELEMNT. Wahoo has not managed the usability of that as well as Hammerhead

Wahoo supports a slightly wider range of sensor types but is unlikely to introduce an app store, instead relying on direct collaboration with sensor vendors (eg Supersapiens and CORE)

Comparison Hammerhead Karoo 3 vs Garmin EDGE

I made a conscious effort for the last year to use a Garmin Edge 540 almost all the time. Honestly, its usability is awful. In comparison, the Karoo has near-perfect usability.

Garmin does have more features but they are often quite specific ones or configuration options, either way, Karoo is catching up quickly. You will find all the high-level features on Karoo like Varia Radar support, routing, ClimbPro and so on. However, Garmin Edge is either the same or has more tweaks and nuances -these provide added complexity which Garmin is rubbish at managing but if you NEED those super-niche features you have no choice but to buy an Edge.

Garmin’s biggest pull for people like me is its CIQ app store. When Garmin’s standard features aren’t up to the job I want to do there is usually an app or a data field that does the job. Karoo is Android-based which ultimately makes it as capable of adding 3rd party features in the long term but as of today, there are few 3rd party data fields to add and the sideloading app process is not user-friendly.

In terms of ‘normal’ functionality, Karoo only lacks a live wind data field and Di2 support. The latter requires ‘sideloading’ the Ki2 app. (Shimano stupidly refuse to allow Hammerhead to directly support Di2)

Then there’s the battery life where Garmin wins.



Hammerhead Karoo 3 Specifications

No review is complete without an exciting list of specifications! Hmm. I’ve indicated the changes from Karoo 2, giving a good indication of the bump in performance.

  • Screen Dimensions 3.2” (unchanged)
  • Display resolution 480 x 800 pixels (was 400x800px)
  • Processor Quad Core 2.0 GHz (was Quad Core 1.1GHz)
  • Memory 64GB Storage (was 32GB), 4GB RAM (was 2Gb)
  • Android 12.0 64bit (was Android 8.0 32bit)
  • Sensor connectivity ANT+ and Bluetooth for cadence, power, FE-C, HR, speed, Varia Radar and electronic shifting (unchanged, Di2 not directly supported but is via Ki2 app)
  • Satellite Connectivity Multi-band (L1+L5)  (was single-band)
  • Satellite constellations GPS, GLONASS, Galileo, QZSS, BEIDOU (was GPS+ GLONASS)
  • Onboard sensors: Barometric Altimeter, ambient temperature, gyroscope, magnetometer, accelerometer, ambient light
  • Charging USB-C (unchanged)
  • Charge time 30% in 30 minutes, 100% in 2.5 hours (was 3 hours to 100%)
  • Battery Life 15+ hours (was 12 hours, claimed 30% improvement)
  • Battery Capacity: 3300mAh (was 2500mAh)
  • Water resistance IP67 (unchanged)
  • Interface: 5-button and touchscreen (was 4 buttons and touchscreen)
  • Cellular – inbuilt SIM now NOT SUPPORTED (was supported up to 4G)
  • Notifications/Alerts – supported on Android and iOS via partner app. (Previously only on Android)
  • WEIGHT 118 GRAMS (was 131g)
  • Integrations: Training Peaks, Strava, Komoot, RwGPS, Xert, Suunto, Trainer Road,  AXS Web, Sentiero


Hammerhead Karoo 3 – Screen

The screen is great. One of the best, if not the best. It is highly readable, crisp and clear in all light conditions.

The previous model supposedly was less readable with strong overhead sunlight but I never experienced that. Anyway, the new screen is claimed to be better. It shows smartphone-quality graphics and the touchscreen works as well as modern smartphones with similar limitations.

There is also a rain lock for the screen plus the pull-down system tray allows auto brightness to be overridden mid-ride.

Hammerhead Karoo 3 Review Third Edition
Tile Format & Backgrounds Are changeable

Hammerhead Karoo 3 – Battery Life

My longest battery test was just over 9 hours of continuous recording.

Test Conditions: I was not continuously moving and the ride included several coffee stops with the Karoo left running. It was a hot, sunny day and the brightness was set to automatic. Because it was bright with direct overhead sunshine I assume the screen brightness was automatically increased thus consuming more battery. I had a power meter, Garmin heart rate monitor, Garmin Varia radar and CORE sensor paired plus I was following a route. Perhaps I had the map screen on display for a third of the time. I used the CLIMBER feature but not Strava Live segments.

The graph shows the Karoo starting at 65% battery which is not correct, it was 100% charged. Perhaps the battery usage rate is correct? Interestingly, it replicates the rate of decline in the FR965 battery on the same ride. The reported battery charge at the end was 35% (as shown on Karoo, not in the FIT file), meaning it probably had another 4.5 hours of life at similar usage rates. ie 13.5 hours. That battery life matches the claimed 15+ hours which would be in more favourable conditions ie less bright, not following a route and paired to fewer sensors.

The new power button, when pressed during a ride, turns the screen off but keeps recording. This will significantly extend the battery life but kinda defeats the point of having a bike computer!

Karoo DOES have an auto power-off feature when not in use. That doesn’t seem to work in all situations, very occasionally leading to a flat battery in the morning, I never quite got to the bottom of when and why that happened but it was rare.

Hammerhead Karoo 3 Contents

You get a high-quality handlebar mount, a Garmin mount adapter, a tether, and a high-quality USB charging cable.

Hammerhead Karoo 3 Box Contents

The Hammerhead mount cleverly allows you to adjust the position in front of your handlebars but will only attach to round handlebars. On the off-chance you break the lugs on the Garmin mount…it’s replaceable without buying a whole new bike computer!

There’s also a GoPro mount option.

Hammerhead Karoo 3 Setup Notes

You’ll set up the Karoo without needing a manual for all the usual basics. I won’t go into all the details but there are several nice, novel touches such as easily disabling ANT+ or Bluetooth to manage and discover your bike sensors.

The following are also worth noting where things get a bit unusual.

  • The new companion app for your smartphone acts as a relay for phone and app notifications plus navigation and safety features. It’s worth pairing to this if you take your phone when you cycle.
  • Go to your online dashboard to link Strava, ride With GPS, Komoot and other services to sync routes and training plans. You can use SRAM credentials to log in to the dashboard.
  • You might also want to link your dashboard to Suunto. Then use the Suunto app on your smartphone as a ride analysis tool. As a bonus, if you have a Suunto Watch you can combine your runs, rides and wellness data in one place.
  • Plan complex routes in the web dashboard

Hammerhead Karoo3 Review

Deep Dive: Hammerhead Karoo As a BikeNav

Karoo 3 offers an excellent all-round routing & navigation experience. It’s a complete package and it works well.

Overview: Hammerhead’s web dashboard contains all your routes including those created in the dashboard or synced from Komoot, Strava or RwGPS. Supported route types are ‘highly advanced’, and include turn-by-turn instructions, off-route POIs and elevation profiles. On the Karoo, a few taps on the map screen and your route is loaded with optional directions to start it. Suunto heatmap and Mapbox OSM maps are used to create and favourite routes on the Karoo with full TBT instructions, surface preferences and re-routing capabilities.

Upload completed rides selectively

Following a route on the Karoo is a joy. In my opinion, the route colours and direction arrows have a near-perfect blend of beauty and usability. Turn messages and information are small when not so important but larger and animated when needed – for example when approaching a turn.


Problems: Once I favourite/pin a route on RwGPS I expect it to just appear on Karoo. It doesn’t. I need to sync the dashboard and sometimes also the Karoo.

The heatmap map overlay is useful but it seems outdated and slightly clutters the screen when not needed. I’d still leave it on though.

Rerouting after going off course is generally very good. However, re-routing is to the closest point and doesn’t always route to the most efficient point on the route.

Garmin may have a few more map/routing features, its interface is just not as good. My preference for navigating is either a simple route presentation from the likes of Wahoo or a well-designed experience like the one from Hammerhead.


Following a route

Street names and turn-by-turn instructions are only part of the in-ride experience with Karoo 3. The coloured route & directional arrows clearly show where you need to go.

A small section of the lower screen indicates the distance to the next turn (56m, above). When you get significantly closer, say about 60m away, a much larger area appears giving the street name (Ruxbury Road), direction to turn and a countdown of the distance. Even better, the popup has a progress bar that changes to match the distance from the turn. It’s clear what to do and when to do it.

Should you miss a turn, re-routing kicks in after 5 seconds, and you are re-routed in red. This is broadly similar to Wahoo’s approach but WAY prettier.

Notice that at the bottom of the 4th image are three small yellow, blue, and purple bars. Each represents more features you can drag up onto the main screen. If you drag up the yellow bar you get the route features. (Blue is CLIMBER and purple is LAP/INTERVAL). There is also a fourth one, grey, for notifications.


Anecdote: Being Negative – At a recent Sportive, I pre-loaded my route with Karoo navigating me to the start. The route started and finished at the same place and Karoo finished the route just as I started at the official start time. It was a bit of a faff to keep up with my group, clear and re-load the route from the tray at the top of the screen, made more difficult by the screen not always responding to the subtleties of the taps of my gloved fingers. I then somehow managed to disable the default zoom and centring of my position on the map with route-up orientation. I put this all down to ‘user error’. When it was working it was awesome!


Hammerhead Karoo 3 As a Performance Bike Computer

If you want to display the core numerical metrics then Karoo 3 offers the same as Garmin and Wahoo plus obscure yet useful ones like “last lap NP”. Garmin supports yet more esoteric metrics either to support unusual sensors or via 3rd party data fields.

Garmin and Karoo offer charts and colours when displaying some metric styles, however, there is very little prettification from Wahoo and you’ll be lucky to get a colour-coded data field. Hammerhead takes prettification to a level beyond Garmin with numerous design flourishes like carefully edged data boxes and charts.

All three vendors support FE-C controllable indoor trainers, CORE body temperature, and power meters. Unlike Hammerhead, both Garmin and Wahoo support Muscle Oxygen sensors natively, yet only Garmin is almost guaranteed access to the latest, greatest sensor be that Activelook HUDs,  NIX Hydration sensors, or one of the new crop of aero sensors about to hit the market. I’d guess that less than 5% of performance riders will need any of that kind of extended sensor support that Hammerhead can’t offer.

Other performance features would include STRAVA LIVE SEGMENTS and CLIMB assistance which I’ll cover in a second. All three bike computer makers do a similar and good job with both Strava and Hills. However, once again Hammerhead does it in a prettier and more usable way.


When following a route, Karoo 3 displays hill climb information similarly to Garmin Edge and Wahoo ROAM units. It’s a neat feature to help you pace your efforts over multiple hills with some great visual cues that beat what is currently offered by Wahoo. It either shows the hills on your planned route or determines the next likely hill based on your direction of travel when no route is loaded. The latter is not a perfect predictor but is as good as Garmin/Wahoo and looks better.

You can slide the CLIMBER tray upwards for more detail or dismiss it entirely by swiping it downwards.

I like whatever the default definition of a hill is by Hammerhead. On a recent ride, I was pleased that I only had 12 hills to do whereas my ride buddies had on the Wahoo 😉 !! It’s an omission not to allow user definition of hills as implemented by Wahoo and Garmin.

Over the last couple of years we’ve seen the key bike computer companies introduce a screen that pops up to give metrics on the progress of the next or current climbs, be that when following a route or free riding. They all break down the climb into its various grades and give similar metrics indicating distances to go both on the road and vertically. Once again Karoo’s visualization is the best and is most easily dismissed if not needed, however, Karoo cannot adjust the sensitivity of the climb parameters thus Garmin and Wahoo both allow you to determine how long and how steep a climb should be for the feature to work. This sounds trivial but it’s not. I’ve used these features for a few years now and they get annoying if the climbs appear too often, so you end up disabling the feature only then to wish it was working when you are exploring some new climbs the next weekend.

This is one of those handy features to have and I know that for some riders it counts as an essential feature. Having used all the manufacturers’ versions I would say that none are correct, they can get the grade wrong, the position on the hill wrong and the top/bottom of the hill wrong. They are all good or bad in different ways depending on your preferences. Karoo’s looks better and works smoothly. I especially liked the ease by which it could be dismissed with a simple swipe.

Strava Live Segments

I’d count Strava Live Segments as a ‘performance’ feature and the Karoo 3 edges Garmin on this one with a well-thought-through screen to 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!


Indoor/Outdoor Workouts with a Smart Trainer

Within seconds, Karoo 3 immediately syncs 3rd party training plans and custom workouts that you might create, or load from, Training Peaks/Xert. These workouts control modern smart trainers using ANT+ FE-C. The initial downside was the inability to store my favourite workouts on the Karoo.

The workout execution and compliance screen has limited customisation options but does allow scrolling through the compliance metrics and their target. It seems odd that I can see every completed interval plus my current effort. A lot is going on visually, made worse by the screen’s ability to scroll down to yet more information. Sometimes I was distracted from the interval target by the metric for my current level which is on a slider and keeps changing position on the screen.

That said, it is a powerful workout tool with many nice featurettes. For example, to end an interval or scale the workout requires access to the top drawer which you drag down. That beats cluttering up the main workout screen.

Other than that, Karoo does a reasonable job and looks OK while doing it. However, this is the one screen where the design needs revisiting. It’s great that Karoo has tried to re-imagine what has come before but I think highly usable solutions exist eg from Wahoo.

Electronic Groupset Integration

If you want the speed and certainty of SRAM AXS/Shimano Di2 shifting then Karoo 3 gives you the key goodies: the ability to change the 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), however to get this to work on Di2 you will need to use the third party Ki2 app.

82mm HUNT Wheels and CORE Sensor. Hmmm
82mm HUNT Wheels and CORE Sensor. Hmmm

Power Meters

If you have a power meter then advanced cycling dynamics are supported for display and recording namely LR Balance, Pedal Smoothness, Torque, Torque Effectiveness and calories-from-power, you don’t get Power Phase and Platform Centre Offset though.


Hammerhead Karoo 3 Accuracy Review

It’s Accurate, with one caveat

I’ve completed a 120-miler and many other road rides with Karoo 3 (easily over 500 road miles plus many more indoor rides at the time of publication). It’s as accurate or more accurate than every other device I tested including Garmin Edge 540, Wahoo Elemnt BOLT 2, Garmin Forerunner 965, Polar Grit X2 Pro and Apple Watch. Every GPS track was as near to perfect as it needed to be.

However, note that getting a good GNSS track on the road is a relatively easy ask. All the other devices were fine too but sometimes their tracks strayed slightly from the actual route by a few metres. I have only done one off-road ride which was also fine but not in challenging GPS conditions. If you are riding gravel through dense forests of deep canyons expect some deviation in the track.

I would have liked it if Hammerhead included the ability to disable the dual-band reception for road riding. It would probably add an hour or two of battery life and the accuracy would be good enough.

Automatic Elevation correction is based on air pressure and does not seem to be adjusted during the ride based on 3D GPS even though it should. This will lead to errors in changeable weather. Manual elevation correction is possible, I tried that and it didn’t always save the value.

In the following example, Karoo reported consistently low and with a bigger variation to the other devices by the end of the ride. Something is not quite right, but it’s OK for my purposes [Hammerhead noted that NOT syncing to the Companion App before starting a ride can cause these kinds of elevation errors, even so, 3D GPS should correct it]

In only one example, below, I found a significant elevation offset. I manually calibrated twice the night before the ride and the ride followed directions to the start of a course at 1hr40. I checked with another reviewer, dcrainmaker, who found a similar error.

Unusual & Notable Extras

  • Karoo 3 has a good and novel mounting system, handily it comes with an adapter for Garmin mounts
  • 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 all kinds of charts. The metrics that can be chosen for the screens are wide-ranging
  • Multiple bike or ride-type profiles are possible however all are recorded as BIKE and not MTB or Road bike.
  • One of the interesting quirks is that during set-up, dynamic and changing data is displayed in the data fields. It’s a nice touch and helps you visualise the final screen aesthetics.
  • Many visual elements relating to the display of your ride data are superior to anything else on the market. There is aesthetic beauty to the design, layout and subtle animation of everything from a heart rate zone display, to the distance to a turn, to the progress vs the KOM on your active STRAVA segment. The best screen resolution on the market boosts all.
  • You can change the priority of your paired sensors and restrict sensors to each ride profile.
  • You can sideload and run any Android APP that does not require Google Play Services. Details below.
  • Download your post-ride FIT file via AXS Web and TCX via Strava
  • Cut and paste a URL that displays a route eg from Google Maps into the web dashboard to create a route. Annoyingly this can’t be sent to the companion app in the same way.
  • Use Hammerhead’s Chrome Route Grab extension to grab routes into the dashboard with one click.


Karoo 3 – Other Smart & Safety Features

Of Particular note is Karoo’s support for rear-facing radars. Garmin’s RTL515 is the best of those radar tail-lights but Karoo presents the traffic safety information better than all the other bike computer companies., albeit only on the left side of the screen.

Karoo will also work with a front-facing awareness light like the Ravemen FR160 / FR300 utilising its Garmin mount.

The new companion app lets you create and share a live tracking link. Annoyingly the person checking your progress can only see where you are and not where you have been


DEEP DIVE: Karoo Companion app For Smartphone

At first sight, the Companion App doesn’t seem to do anything. There is one, solitary button to share a live tracking link.

Instead, think of the Companion App as smart glue. It lets you send ‘things’ from your smartphone/internet to the Karoo – ‘things’ include routes, workouts and messaging notifications.


I liked how the old Karoo was able to have its own SIM card. The reality must be that many more people will take their smartphone cycling than have a spare SIM card. Thus Karoo has to keep up with the competition and provide in-ride notifications from the smartphone and the new iOS app (and Android) does that. There are messaging notifications from apps like WhatsApp plus Karoo’s live tracking feature, all of which can be configured for each ride profile.

Notifications seem to work well and some example screens are shown below. I particularly like the clarity of the colours and fonts used for the notification and the ease by which the notification tray can be swiped up/down to hide them. It seems the full list of notification details is kept for your entire ride (maybe until you dismiss the notification on the phone?).



In Ride Caffeine Problems – an Anecdote

How many times have you cycled with your buddies somewhere new and had an uncontrollable group urge for cake and coffee but no idea where the nearest coffee shop was? Be honest, how many times did someone end up using their smartphone rather than their Garmin to find the eatery?

It’s easier to use Google Maps or Apple Maps, so we do it. Hammerhead accepts this and now once you find your coffee shop on Google Maps you can send its location to the Karoo Companion App and then calculate the cycling route on the Karoo itself. Here are the steps to get an excellent Coffee and Pastéis de nata at Giro, Esher.



You can apply the same principle to navigate to any other point on Google/Apple Maps.

Sharing a Route – Another Anecdote

How often has your group struggled to get a Strava or RwGPS route on everyone’s bike computers? It’s sometimes easier to share a GPX route via a WhatsApp group or simply to AirDrop, mail or text it. It’s not always the easiest thing being the recipient of that GPX file in a car Park at the start of a ride with no WiFi.

Here is an example of sending a GPX file from the Apple FILES app. It’s equally as easy to use a GPX file that was a WhatsApp attachment. Share it to the Hammerhead app. The route appears within seconds on Karoo.


It’s not as elegant a solution as using a Strava or RwGPS route but this is a sometimes more practical approach.

Sharing A Workout

By the same principle as route sharing, you can send a workout file to the Karoo companion app and sweatily execute it a few seconds later.

The Future of the Companion App

What we see today must be the first step for this app. No doubt there will soon be new features added here like the ability to reply to messages with pre-canned responses. Perhaps the companion app will also become a conduit for adding 3rd party apps (APKs) or even for easier access to completed workout files (FIT).


Karoo 3 Apps – dedicated Karoo apps and sideloaded generic Android apps

If you are unhappy with any aspect of Karoo you can transform Karoo. Perhaps you would prefer to record your workout using Xert, RwGPS or Strava. No problems.

IE you can use the XERT Android app to control and follow structured workouts or you can look at your Strava account on your Karoo after you’ve finished your Sunday ride. You can even run the Spotify Android app.

Any Android APK app can be sideloaded onto Karoo provided Google Play Store access is not required. The sideloading method is unchanged from Karoo 2 and here is a short version of the 3 steps using a Windows PC

  1. Create one folder and use it for everything. Use: “c:\android”
  2. Plugin your Karoo and enable it for sideloading: Karoo> Settings> About> repeatedly tap on “Developer Options”
    • Enable developer options: Karoo> Settings> Enable “Developer Options”
  3. Open a command prompt with administrator rights: windows>start>run>cmd.exe
    • Type: “cd c:\android”
    • Type: “adb install spotify.apk” or whatever you have called the APK
  4. Sorted. Although you will have to install updates yourself.

Some apps will not have APKs, some will have APKX . Only APK works.

There is no way to use a file-sharing service like Dropbox, Google Drive or Microsoft OneDrive. I’ve tried. Hammerhead confirmed it’s not possible. Hammerhead would need to write a Dropbox integration (please do!! Wahoo did!)

A few dedicated apps are written specifically for Karoo including Ki2, a workaround app to get Di2 working on Karoo. Karoo’s SDK was not working before launch so I couldn’t test these but they work on Karoo 2.




Wider thoughts – Hammerhead Karoo 3 Review

Karoo 3 is the real deal. There is nothing intrinsicly wrong with it and scope exists to improve key features round the edges. as with most new products, there are a few bugs but I won’t cover them here as Hammerhead will probably fix them quickly.

Whilst this is a significant hardware bump by Hammerhead, there is more to talk about.

The Companion App is clearly a strategic product, its introduction mirrors the demise of the onboard SIM capabilities of the earlier model. Hammerhead recognises that most cyclists carry a smartphone and has decided to work with that reality rather than try to replace or replicate the benefits of our phones. Fair enough.

Hammerhead gives the impression of finding real-life cycling problems and working out innovative ways to solve them beautifully. Contrast that to some competitors who seem to relish playing catch-up to Garmin’s latest feature and thoughtlessly adding yet another menu option. How Hammerhead solved the unscheduled coffee shop dilemma (above) is another example of how they’ve adapted to the behaviour of real cyclists in a slick and relatively seamless way.

You can apply a similar description to other Karoo features such as the colour coding and numeric countdown to turns when navigating. That and many other examples cry out ‘CYCLING DESIGN CLASSIC’ yet, on your Sunday Ride, you probably won’t see one on any handlebars. Maybe Karoos don’t look that different to a Garmin or Wahoo and you don’t notice them? The reality remains that lots of people still buy Garmin because of its features and brand awareness. Garmin seems to be the safe, default choice. Slightly more informed riders who either want a hassle-free ride experience or who have invested heavily in Wahoo’s indoor cycling ecosystem seem to go for the ELEMNT.

How does Hammerhead compete in this kind of market?

A certain kind of cyclist wants a good-looking bike computer to match a good-looking bike and good-looking cycling apparel. Fair enough. Karoo targets those people but how many are there? Similarly, the whole issue of route creation, curation, sharing and following certainly can be a royal PITA at times. Hammerhead has made significant strides at improving the navigation experience to the point where you could say they are the market leader in the overall navigation experience. But how often do you navigate new routes or need to follow a specific route, I’d imagine it’s once a week at best for almost everyone….maybe 20 times a year? Is that a reason to buy the Karoo or just enough to keep you enduring the idiosyncrasies of one of the other bike navigation companies, who still get you there in the end?

I don’t have an SRAM AXS Groupset but I did miss the Ki2/Di2 integration I’m used to. I expect that to be resolved VERY quickly. But it raised the thought that perhaps Hammerhead has the longer game in mind too. Integration with AXS (electronic shifting) has been significantly boosted and it’s interesting to note that with Competitive Cyclist in the USA, Karoo is initially only available as part of the SRAM RED Upgrade kit. This points to a $/€/£500ish bike computer becoming an integral part of a high-end groupset, perhaps being included for free as a sweetener with new bikes. No doubt Karoo will thus find its way onto many of the new bikes that come kitted with SRAM groupsets and so, progressively Karoo will become ever-more visible. Karoo is here to stay.

Will I go back to Wahoo or stay with Hammerhead?

I’m fed up with the Edge I’ve used for about a year. I’ve not enjoyed it but there is no BOLT/ROAM replacement I know of coming soon, so I guess I’ll stick with Karoo for a while and revert to my Edge if I need to test or use an unusual feature for this blog.

Recommendation: Yes

Worth the upgrade from Karoo 2: No. Nor from Edge 530/830 nor Element Bolt/Roam 2. But yes, upgrade from most other things.

Please support the work here from time to time if you decide to purchase one or enjoy the content. There are no ads, I’m not paid and I need to eat 😉

Clicks to offer at Hammerhead.io

Hammerhead Karoo 2 Discount, Price, Availability, Review Summary

The price is high but probably set correctly for a high-quality, mid-sized touchscreen bike navigation computer.

  • AUSTRALIA $749.99 AUD
  • CANADA $699.99 CAD


Clicks to offer at Hammerhead.io


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2 thoughts on “[2024] Karoo 3 Review ❌14 cons ❌, ✔️14 Pros✔️ Hammerhead’s Third Generation GPS Bike Computer

  1. Even bigger battery (more than 3x the mAh of an 840, for about half the runtime 🤯), and yet they managed to reduce weight compared to the K2. Garmin *really* needs to step up their weightweenyism, it starts getting absurd how much case Garmins carry around for their (theoretically) delightfully small batteries. Garmins not being noticeably lighter than their battery-guzzling competition is such a wasted opportunity!

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