Tested: Hammerhead Karoo (3) Review

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There’s this old adage that your phone has more computing power than the Apollo 11 capsule that put man on the moon. It’s one of those fun facts that’s gratifying to have banging around in my head, but is completely useless in everyday life. But, with the new, 3rd edition Hammerhead Karoo, and its 4GB of computing power, I have more than a million times the computing power of that spaceship strapped precariously to my bike’s handlebars.

I’ve had a bit of an on-again/off-again relationship to bike computers over my time as a mountain biker, with most of my time spent sans computer. But when the new Karoo found its way into my life, I was eager to test its mettle.

About the third gen Karoo

While this is technically the third Karoo, Hammerhead doesn't call it the Karoo 3, or K3, so I'll just refer to it as the Karoo throughout. Hammerhead has been designing bike computers since 2013, but this 3rd edition of the Karoo is the first computer they’ve released since being purchased by SRAM in early 2022. This third edition of the Karoo has all the upgrades you’d expect from a new computer: more memory, better battery life, and a brighter screen. It also comes with Hammerhead’s companion app, which allows it to sync to your phone - we’ll dive deeper into that later.

Hardware and mounting system

The Karoo has one new button over the Karoo 2—a dedicated power button that can also shut down the screen to help conserve battery, and remove distractions. It also has four side buttons, and a handy USB-C charging port. The 3.2” touchscreen has a built-in ambient light sensor, so it automatically adjusts for changing light conditions. I was especially impressed by how legible the screen is in direct sunlight.

The Karoo uses Hammerhead’s own proprietary mount system. This system is sleek, and easy to use, but doesn’t play nicely with other computers or accessories. I ended up defaulting to the quarter turn mount adaptor that comes standard in the box. If you’re going to use a proprietary mount system, you’d best make it easily adaptable to the de-facto standard, and I’m stoked Hammerhead did that here.

Software and functionality

Right out the gate, the Karoo 3 made me feel old. Not because it’s hard to use - everything is pretty intuitive, but because it’s so good. It wasn’t that long ago that I would have killed for a phone with a touch screen that worked this well, with software that ran this smoothly. It’s wild how quickly technology has progressed to the point where a humble bike computer is more powerful, intuitive, and elegant than the top-of-the-line phones from not that long ago. I know it’s sort of to be expected, but using the Karoo really hammered that home for me. It feels so nice , I’m supposed to strap this to my bars and go for a ride? Shouldn’t I put some sort of case on it? Install some sort of screen protector? Nope. This is just what bike computers are now.

All that said, read the directions. Especially as a mountain biker, the Karoo’s default settings have a definite road flavor that I needed to consciously work to undo. Set the default navigation to “dirt”, figure out how to mute the notification beep, and customize the data fields to display the stats you find relevant.

None of this is hard to do, but it’s all best done in the comfort of your living room, not out on the trails, with sweaty fingers, while your friends tap their toes impatiently.

It’s very easy to connect the Karoo to your SRAM AXS drivetrain, and it can track your shifting, as well as send you alerts when your batteries are running low. It’s also easy to connect it to your phone, so that all your distracting notifications can stream directly to your handlebars. However, there’s no option to cull notifications based on what app is sending them, so I turned this all the way off. With sport watches, I’ve appreciated the ability to receive notifications for calls and texts, but not Instagram, and if I could do that with the Karoo, I’d be much more likely to leave phone notifications on.

It should also be easy to connect your heart rate monitor and/or power monitor to the Karoo. I have not done that because last time I had a heart rate monitor, it tried to warn me of an impending heart attack when the waiter brought my chimichanga out at a Mexican restaurant, and I’ve been resentful ever since.

Companion app

Notable for this latest version of the Karoo, Hammerhead has released a companion app. While its functionality isn’t huge right now, Karoo says they’ll continue to develop what it’s capable of. For now, it allows you to send destinations from the mapping app of your choice directly to the computer.

That’s pretty slick - I’ve used it to find a restaurant and then automatically route to it. It can also create a sharable link with your current location - handy for folks who want to make sure you’re not lying unconscious in the woods. While I appreciate this feature, it would be more useful if it gave viewers a line to follow with your route, not just the dot of your current location. And since it relies on your phone for service, I’d stick to other measures for bigger objectives.

The companion app doesn’t have any functionality to change up default screens or settings on the head unit, or create routes. It’s easy enough to play with settings on the computer, but I would appreciate the ability to really dial all of that in on my phone’s bigger screen.

Navigation

The Karoo has a pretty powerful navigation system that should be able to take your preset route, and then, on the fly, adjust the directions it gives you to keep you as on-route as possible. When I experimented with drawing clean routes on my desktop computer, and sending them to the Karoo, it worked very well. The turn-by-turn navigation worked nicely, I really like the climb visualizer, and it did a good job of rerouting me when I intentionally took a wrong turn.

However, I did have one pretty frustrating navigation experience with the Karoo. I loaded a long complicated route that someone else had created in Ride with GPS. This route overlaps and intersects itself multiple times. And, close examination of the route afterwards, loaded into Gaia, revealed that the file I used had multiple small gaps, and weird turnarounds in it. So, not a straightforward route for the Karoo to follow.

Out the gate, the Karoo did a good job of directing me on the route. But once we reached the first complicated section - a climb that we were repeating, before dropping into a different descent, the Karoo got overwhelmed. It started sending me a multitude of navigational directions, none of which were helpful. I knew where I was going, so I pedaled through the incessant beeping. However, at the top of the climb, something happened and the Karoo quit trying to follow the route, and ended the ride file. I tried as many solutions as I could on the fly, booting and rebooting it, stopping and restarting the ride, but to no avail - I lost all ability to follow the route I was on and had to resort to using my phone.

Anecdotally, my partner’s computer, an old Garmin Edge 520 Plus also had some pretty catastrophic issues navigating the same route, but not to quite the same extent as the Karoo, so I think the gps track is to blame. In the future, I’m going to make sure that I’ve got cleaner gps tracks to plug into the computer, and hope for better results.

Car-brained bias

This is not just a problem with the Karoo, but instead an old soap box that I’ll take any excuse to drag out. Cycling navigation in general seems to have a road bias. Not towards curly-bared bikes with slick tires, but towards putting cyclists on the road, over bike paths or trails. Even with the default navigation set to “dirt” the Karoo still tends to route me on main roads over bike paths.

Here’s an example: if I want to ride to LaFeens Donuts from my house, the Karoo briefly routes me onto a delightful bike path, but that takes me off the path, and around Whatcom Falls Park the long way, depositing me on a busy road with poor bike infrastructure. Whereas, even Google Maps knows that I should just hop on the path a block from my house, and stay on it, without touching the road for 90% of my journey to a raspberry bear claw.

That bias continued to show through riding around town. The Karoo consistently wanted to put me on main thoroughfares with minimal bike infrastructure, instead of on our excellent bike paths, or quiet side streets with designated bike lanes. And Hammerhead isn’t alone on this, bike computers generally tend to navigate like they’re mounted to a car, not a bike.

Battery life

Hammerhead says the Karoo should be good for 15+ hours of battery life, with the screen on. I have not tested that limit because: a) I do not like riding around with my screen on most of the time - I do not need to know how fast I’m going, I already know that it’s fast enough to be dangerous if I’m distracted by my screen. And b) I do not generally go on 15+ hour bike rides. That said, after an 11 hour ride, tracking, and trying to follow turn by turn navigation, I had used 35% of the Karoo’s battery.

Hammerhead says that you can charge the Karoo to 30% in just 30 minutes, so if you’ve got a battery bank, and you’re sparing with when you leave the screen on, I see no issue with it working for multi day adventures.

Other performance impressions

I touched briefly on this above, but in use, the Karoo feels premium. The screen works well, and worked surprisingly well even when my fingers were so sweaty that I couldn’t use my phone's touch screen. The buttons have a nice feel to them, and the software isn’t glitchy or frustrating (other than the previously mentioned navigation snafu.)

The numbers it spits out for vert and distance feel accurate compared to other computers and watches I’m using, and generally, the user interface is quite nice. It was noticeably smoother to export rides to my phone, and I really appreciated the option to name them right on the Karoo’s screen.

For now

This third generation Hammerhead Karoo feels like a premium, refined product. Is it overkill for most of the riding I do? Absolutely. Could a computer wiz reconfigure it to power the Apollo 11 capsule? Probably! It’s been an eye-opening experience using the Karoo, and I’m excited to explore that further in a broader-ranging piece about what mountain bikers could, and should be looking for in a bike computer.

The Hammerhead Karoo is available now.