HAMMERHEAD is a cycle computer manufacturer that has a decent market share, mainly in the United States and outside of Japan.
The product model name is KAROO, but hereinafter I'll refer to it as Hammerhead and Karoo.
The latest model currently available is "Karoo 3," but the model most commonly found in the US market right now is Karoo 2.
Two years ago (according to SRAM's press release on January 19, 2022), Hammerhead was acquired by SRAM.
Up until then, with the Karoo 2 which was the latest model at the time, you could assign the page-turning function of the cycle computer to buttons on the bracket of Shimano's electronic STI levers, and display which gear the chain was engaged with on the screen. But the moment it came under SRAM's umbrella, at Shimano's request, starting with the next update (June 2, 2022), they were told to "disable the convenient Di2 features on Hammerhead's cycle computer," and they removed the functionality.
Only users of Shimano × Hammerhead suffered this harassment.
The message was basically: "Use Garmin's cycle computer, since we get along well with Shimano (to the point of having their people visit the headquarters in Sakai)!"
At that time, this was almost non-existent in Japan, so it wasn't recognized as a problem domestically.
Then recently, SRAM's new RED AXS E1 was announced, and a bonus button was added to the inner front of the lever bracket. In its shipped state, shifting functions are assigned, but you can also assign it to operate the Hammerhead cycle computer that's now part of the component group.
The component I use is Rival AXS, which doesn't have a bonus button on the lever bracket, but it does have the function to display the current gear position and the component's battery level. So I bought "SRAM's Karoo."
As a model, I think it's equivalent to the Karoo 3, but as a cycle computer under SRAM, its official model name is simply "Karoo."
Hammerhead had no distributor in Japan until now, and except for personal imports, hadn't been available domestically. So this time, through SRAM's distributors, marks the first official domestic handling.
First off, what was problematic was that right after the initial startup, I was asked to choose a language from five options—English, German, Spanish, French, and Italian—and then Wi-Fi connection was required.
I have no wireless LAN equipment at either the shop or my house (well, technically I do at home), so I got stuck there on the first day.
Also, while SRAM's website lists Portuguese, Simplified Chinese, Traditional Chinese, Korean, and Japanese as supported languages for Karoo in addition to the above, those options aren't available.
I downloaded the smartphone companion app that Hammerhead offers, but it was completely unhelpful regarding obtaining the offline maps, which I'll touch on later.
By the way, looking at reviews of this companion app from overseas (mainly the US), it's heavily criticized for not supporting Karoo 2.
It seems to be a dedicated app for the Karoo 3 essentially... or rather "SRAM's Karoo," but it's criticized for having a name that doesn't make that clear at first glance.
↑This is the companion app screen on the smartphone.
I selected the item called "Phone Pairing," and
it says to read the QR code displayed on the Karoo screen with the camera function, but
the item called "Phone Pairing" shown in the app doesn't even exist on the device itself!
Come on, seriously?!
...I resolved the phone pairing issue.
If you select the "System Upload" item further down in the Settings menu, the Phone Pairing item gets added, and Japanese language support was also added.
I'll continue using English though.
Eventually, a version with an updated system will be shipped, but currently, without doing a System Upload, you can't select Japanese or link with the app.
I suspect this particular unit still contains the firmware of the Karoo 3 from before "SRAM's Karoo" came out, before there was a companion app and before Japanese support.
But ultimately, even after connecting this app, it didn't help with initial setup.
It seems to be useful for setting up and managing riding routes.
The initial authentication and System Update were completed quickly using Osaka Metro's free Wi-Fi during my commute, but
the map display is still not usable.
For a model that's known to be shipping to Japan, I'd think pre-installing offline maps would be the bare minimum. But this map data is extremely heavy and it took quite a long time to download using free Wi-Fi.
To get the contents out of the box, you have to break a seal that "can't be avoided being broken," so it's impossible for the distributor to pre-install offline maps while keeping the package looking unopened.
So at least I wish the manufacturer would release a version for Japan with Japanese maps pre-installed and a sticker on the box saying "JAPAN MAP INCLUDED."
For a product that came through a properly established official distributor channel rather than personal overseas shopping, I'd expect them to demonstrate that added value there.
I forgot to mention (important), but the recommended retail price including tax for a standalone SRAM Karoo is ¥80,170.
Surprisingly, the distributors currently have inventory (that's why it's here).
What's called the new RED AXS E1 Upgrade Kit consists of SRAM Karoo + left and right levers + front and rear brakes, with a recommended retail price of ¥302,900 including tax, and this is on backorder.
Beyond that, a kit containing the front and rear derailleurs and their battery + charger + 2 disc rotors + chain (basically everything except the crankset and sprocket) is listed at ¥504,600 including tax, limited to 75 units, but this is also on backorder.
Since both disc rotors are 160mm and the charger and 2 batteries are the conventional specifications, existing SRAM users might find it hard to justify purchasing.
So I tried downloading the offline maps using McDonald's free Wi-Fi.
The image shows 5.0GB, but first it quickly showed 4.9GB and then progressed very slowly after that.
It was around 30 minutes later that it reached 5.1GB.
During this process, I confirmed that Japanese language selection was possible.
After that, it didn't progress gradually with time passing. After 5.2GB it seemed to stall, but around the 45-minute mark it suddenly jumped to 8.2GB, and a few minutes later the download completed at 9.6GB.
By the way, the fact that the goal was 9.6GB wasn't clearly indicated anywhere.
Since I started before entering the store, it took about 50 minutes total.
McDonald's free Wi-Fi requires you to enter your email address to use it and cuts off the connection after one hour, so it was a close call.
Finally it's ready to use.
If you long-press the power button on the bottom of the device,
it powers on and shows the logo right away, but this takes quite a while.
I timed it and the logo displays for about 20 seconds, and then there's a bit more animation after that, so it takes just over 30 seconds to fully start up.
This is what I think is the Karoo's greatest feature—the screen is extremely high quality.
The display is 800×480 pixels (vertical×horizontal), and since the image above is 480×640 pixels, the Karoo's resolution is "the resolution of the image above but 1.25 times longer in the long direction in portrait orientation."
The name of the program that determines the display items being "Baltan Seijin" is not a default specification from the manufacturer.
There were several program names like "BASIC PROGRAM" and "INDOOR," but I deleted the others and renamed it.
The default showed
BASIC
PROGRAM
across two lines, but since line breaks aren't possible, I was wondering how it was done, and then
if you add spaces appropriately, at some point it wraps to a second line.
↑I actually wanted to put a space here, but I hit the character limit exactly.
↑If I add a space, this is what happens.
You set the page layout for the program.
In the image above, it shows "3 pages total including a map page," but the default is 2 pages.
On the layout settings page, numbers and graphs move as examples, but the speed item changes at an impossibly fast rate.
Maybe they're making it clearly obvious that this is a setup screen and not actual data.
The map displayed is also a fictional one (or at least I'm not sure if it's a real place).
After deciding on the layout, you configure which display items to assign, but there's only one page that includes the map.
For pages other than that, if you press the plus button here you can add more, with a maximum of 12 pages including the map page.
This is also a simulated graph, showing the elevation profile of your ride so far.
You can also choose to display another elevation graph showing the elevation up to a destination if you've set one.
When you select the gear position graph display, it looks like this.
Since I'm running a front single, I don't actually have front gear display or front derailleur battery level display.
Among the display item options, there's one called tire pressure.
↑This is also simulated data during configuration, but from the power meter brand QUARQ, there's a sensor that attaches to the valve part of the tire called the TYRE WIZ, which allows tire pressure to be displayed on the cycle computer.
The ZIPP 303 I recently rebuilt has a hookless rim and the stated maximum pressure is 5 bar, but most people operate them around 3.6–3.8 bar.
With 23C tires at around 7–8 bar, a 1 bar drop isn't a problem for riding itself, but dropping from 3.6 to 2.6 bar would be a major issue, so it's nice to be able to monitor this.
But I wonder—can you see the pressure fluctuations in real time when braking or leaning the wheel in corners?
If so, that would be interesting.
What I'm more curious about is that with rim brake wheels, I imagine the rim pressure increases noticeably due to brake heat on descents, and I'd like to know how much it actually rises.
I launched the program.
Even with the offline maps installed, the map won't display until the satellite is acquired and your location is determined.
It supports GPS, GLONASS, Galileo, QZSS (Michibiki), and BEIDOU (called "Hokutou" in Chinese—China's satellite system) across five systems, but satellite icons don't appear on screen.
There's a slightly anxious wait, but
suddenly the map appears. The image quality is excellent.
At maximum zoom in, it looks like this
Moving away from the arrow that centers on you and into destination search mode to view Sakaisuji, it looks like this
At maximum zoom out, it looks like this.
You can switch map zoom by tapping the screen, but it requires a bit of a knack and the results feel a bit unstable, so it's more reliable to use the physical buttons on the side of the unit.
Even with long-finger gloves on, there are no problems.
The right button on the top of the unit:
Short press turns the page right
Long press zooms the map in
The left button on the top of the unit:
Short press turns the page left
Long press zooms the map out
The left and right buttons on the bottom of the unit give the same results as tapping the bottom left and right of the screen, but the actions are clearly marked with icons.
This is the program selection screen, and if you tap the left icon you go to the settings screen, and if you tap the right icon you go to the layout screen configured for that program. But pressing the bottom left and right physical buttons gives the same result.
The right icon is for starting the recording, and the left is a checkered flag, which is the icon for ending the program.
From here, if you tap the left icon or press the bottom left button,
it asks for confirmation that you really want to end, with a back button on the left and this time the checkered flag on the right. If you tap the right icon or press the bottom right button, the recording ends.
Next, a choice appears on the bottom left and right asking whether to save it.
Right saves it, and left is a trash icon for deleting it. If you tap the left icon or press the bottom left button,
it asks for confirmation about really deleting it, with the trash icon now appearing on the right.
The tactile feel of the physical buttons is so satisfying that in the short time I've used it, I've barely touched the touchscreen.
The "Key Button Icon"—the explanatory icon showing "what will happen if you press the bottom physical button right now"—can be turned off in the settings if you don't need it.
The back of the unit.
The Karoo 3 came out after SRAM acquired Hammerhead, but it still doesn't have SRAM marking here.
This is "SRAM's Karoo," so it has SRAM markings.
The Hammerhead Shark sticker—the adorable hammerhead shark—is not part of the default specifications, just so you know.
The small hole in the image was surrounded by a circle on the Karoo 3 with "BEEP" (electronic sound) marked on it to indicate it was a sound-producing hole, but the SRAM Karoo has no such marking.
Once you're in the ride program, if you long-press any point on the map, you can separate your consciousness from your current location (I'm using that term loosely), and from there if you tap another point on the map, you'll be asked whether you want to start navigation to that point or just place a landmark pin.
If you select navigation, a beep sounds
The product model name is KAROO, but hereinafter I'll refer to it as Hammerhead and Karoo.
The latest model currently available is "Karoo 3," but the model most commonly found in the US market right now is Karoo 2.
Two years ago (according to SRAM's press release on January 19, 2022), Hammerhead was acquired by SRAM.
Up until then, with the Karoo 2 which was the latest model at the time, you could assign the page-turning function of the cycle computer to buttons on the bracket of Shimano's electronic STI levers, and display which gear the chain was engaged with on the screen. But the moment it came under SRAM's umbrella, at Shimano's request, starting with the next update (June 2, 2022), they were told to "disable the convenient Di2 features on Hammerhead's cycle computer," and they removed the functionality.
Only users of Shimano × Hammerhead suffered this harassment.
The message was basically: "Use Garmin's cycle computer, since we get along well with Shimano (to the point of having their people visit the headquarters in Sakai)!"
At that time, this was almost non-existent in Japan, so it wasn't recognized as a problem domestically.
Then recently, SRAM's new RED AXS E1 was announced, and a bonus button was added to the inner front of the lever bracket. In its shipped state, shifting functions are assigned, but you can also assign it to operate the Hammerhead cycle computer that's now part of the component group.
The component I use is Rival AXS, which doesn't have a bonus button on the lever bracket, but it does have the function to display the current gear position and the component's battery level. So I bought "SRAM's Karoo."
As a model, I think it's equivalent to the Karoo 3, but as a cycle computer under SRAM, its official model name is simply "Karoo."
Hammerhead had no distributor in Japan until now, and except for personal imports, hadn't been available domestically. So this time, through SRAM's distributors, marks the first official domestic handling.
First off, what was problematic was that right after the initial startup, I was asked to choose a language from five options—English, German, Spanish, French, and Italian—and then Wi-Fi connection was required.
I have no wireless LAN equipment at either the shop or my house (well, technically I do at home), so I got stuck there on the first day.
Also, while SRAM's website lists Portuguese, Simplified Chinese, Traditional Chinese, Korean, and Japanese as supported languages for Karoo in addition to the above, those options aren't available.
I downloaded the smartphone companion app that Hammerhead offers, but it was completely unhelpful regarding obtaining the offline maps, which I'll touch on later.
By the way, looking at reviews of this companion app from overseas (mainly the US), it's heavily criticized for not supporting Karoo 2.
It seems to be a dedicated app for the Karoo 3 essentially... or rather "SRAM's Karoo," but it's criticized for having a name that doesn't make that clear at first glance.
↑This is the companion app screen on the smartphone.
I selected the item called "Phone Pairing," and
it says to read the QR code displayed on the Karoo screen with the camera function, but
the item called "Phone Pairing" shown in the app doesn't even exist on the device itself!
Come on, seriously?!
...I resolved the phone pairing issue.
If you select the "System Upload" item further down in the Settings menu, the Phone Pairing item gets added, and Japanese language support was also added.
I'll continue using English though.
Eventually, a version with an updated system will be shipped, but currently, without doing a System Upload, you can't select Japanese or link with the app.
I suspect this particular unit still contains the firmware of the Karoo 3 from before "SRAM's Karoo" came out, before there was a companion app and before Japanese support.
But ultimately, even after connecting this app, it didn't help with initial setup.
It seems to be useful for setting up and managing riding routes.
The initial authentication and System Update were completed quickly using Osaka Metro's free Wi-Fi during my commute, but
the map display is still not usable.
For a model that's known to be shipping to Japan, I'd think pre-installing offline maps would be the bare minimum. But this map data is extremely heavy and it took quite a long time to download using free Wi-Fi.
To get the contents out of the box, you have to break a seal that "can't be avoided being broken," so it's impossible for the distributor to pre-install offline maps while keeping the package looking unopened.
So at least I wish the manufacturer would release a version for Japan with Japanese maps pre-installed and a sticker on the box saying "JAPAN MAP INCLUDED."
For a product that came through a properly established official distributor channel rather than personal overseas shopping, I'd expect them to demonstrate that added value there.
I forgot to mention (important), but the recommended retail price including tax for a standalone SRAM Karoo is ¥80,170.
Surprisingly, the distributors currently have inventory (that's why it's here).
What's called the new RED AXS E1 Upgrade Kit consists of SRAM Karoo + left and right levers + front and rear brakes, with a recommended retail price of ¥302,900 including tax, and this is on backorder.
Beyond that, a kit containing the front and rear derailleurs and their battery + charger + 2 disc rotors + chain (basically everything except the crankset and sprocket) is listed at ¥504,600 including tax, limited to 75 units, but this is also on backorder.
Since both disc rotors are 160mm and the charger and 2 batteries are the conventional specifications, existing SRAM users might find it hard to justify purchasing.
So I tried downloading the offline maps using McDonald's free Wi-Fi.
The image shows 5.0GB, but first it quickly showed 4.9GB and then progressed very slowly after that.
It was around 30 minutes later that it reached 5.1GB.
During this process, I confirmed that Japanese language selection was possible.
After that, it didn't progress gradually with time passing. After 5.2GB it seemed to stall, but around the 45-minute mark it suddenly jumped to 8.2GB, and a few minutes later the download completed at 9.6GB.
By the way, the fact that the goal was 9.6GB wasn't clearly indicated anywhere.
Since I started before entering the store, it took about 50 minutes total.
McDonald's free Wi-Fi requires you to enter your email address to use it and cuts off the connection after one hour, so it was a close call.
Finally it's ready to use.
If you long-press the power button on the bottom of the device,
it powers on and shows the logo right away, but this takes quite a while.
I timed it and the logo displays for about 20 seconds, and then there's a bit more animation after that, so it takes just over 30 seconds to fully start up.
This is what I think is the Karoo's greatest feature—the screen is extremely high quality.
The display is 800×480 pixels (vertical×horizontal), and since the image above is 480×640 pixels, the Karoo's resolution is "the resolution of the image above but 1.25 times longer in the long direction in portrait orientation."
The name of the program that determines the display items being "Baltan Seijin" is not a default specification from the manufacturer.
There were several program names like "BASIC PROGRAM" and "INDOOR," but I deleted the others and renamed it.
The default showed
BASIC
PROGRAM
across two lines, but since line breaks aren't possible, I was wondering how it was done, and then
if you add spaces appropriately, at some point it wraps to a second line.
↑I actually wanted to put a space here, but I hit the character limit exactly.
↑If I add a space, this is what happens.
You set the page layout for the program.
In the image above, it shows "3 pages total including a map page," but the default is 2 pages.
On the layout settings page, numbers and graphs move as examples, but the speed item changes at an impossibly fast rate.
Maybe they're making it clearly obvious that this is a setup screen and not actual data.
The map displayed is also a fictional one (or at least I'm not sure if it's a real place).
After deciding on the layout, you configure which display items to assign, but there's only one page that includes the map.
For pages other than that, if you press the plus button here you can add more, with a maximum of 12 pages including the map page.
This is also a simulated graph, showing the elevation profile of your ride so far.
You can also choose to display another elevation graph showing the elevation up to a destination if you've set one.
When you select the gear position graph display, it looks like this.
Since I'm running a front single, I don't actually have front gear display or front derailleur battery level display.
Among the display item options, there's one called tire pressure.
↑This is also simulated data during configuration, but from the power meter brand QUARQ, there's a sensor that attaches to the valve part of the tire called the TYRE WIZ, which allows tire pressure to be displayed on the cycle computer.
The ZIPP 303 I recently rebuilt has a hookless rim and the stated maximum pressure is 5 bar, but most people operate them around 3.6–3.8 bar.
With 23C tires at around 7–8 bar, a 1 bar drop isn't a problem for riding itself, but dropping from 3.6 to 2.6 bar would be a major issue, so it's nice to be able to monitor this.
But I wonder—can you see the pressure fluctuations in real time when braking or leaning the wheel in corners?
If so, that would be interesting.
What I'm more curious about is that with rim brake wheels, I imagine the rim pressure increases noticeably due to brake heat on descents, and I'd like to know how much it actually rises.
I launched the program.
Even with the offline maps installed, the map won't display until the satellite is acquired and your location is determined.
It supports GPS, GLONASS, Galileo, QZSS (Michibiki), and BEIDOU (called "Hokutou" in Chinese—China's satellite system) across five systems, but satellite icons don't appear on screen.
There's a slightly anxious wait, but
suddenly the map appears. The image quality is excellent.
At maximum zoom in, it looks like this
Moving away from the arrow that centers on you and into destination search mode to view Sakaisuji, it looks like this
At maximum zoom out, it looks like this.
You can switch map zoom by tapping the screen, but it requires a bit of a knack and the results feel a bit unstable, so it's more reliable to use the physical buttons on the side of the unit.
Even with long-finger gloves on, there are no problems.
The right button on the top of the unit:
Short press turns the page right
Long press zooms the map in
The left button on the top of the unit:
Short press turns the page left
Long press zooms the map out
The left and right buttons on the bottom of the unit give the same results as tapping the bottom left and right of the screen, but the actions are clearly marked with icons.
This is the program selection screen, and if you tap the left icon you go to the settings screen, and if you tap the right icon you go to the layout screen configured for that program. But pressing the bottom left and right physical buttons gives the same result.
The right icon is for starting the recording, and the left is a checkered flag, which is the icon for ending the program.
From here, if you tap the left icon or press the bottom left button,
it asks for confirmation that you really want to end, with a back button on the left and this time the checkered flag on the right. If you tap the right icon or press the bottom right button, the recording ends.
Next, a choice appears on the bottom left and right asking whether to save it.
Right saves it, and left is a trash icon for deleting it. If you tap the left icon or press the bottom left button,
it asks for confirmation about really deleting it, with the trash icon now appearing on the right.
The tactile feel of the physical buttons is so satisfying that in the short time I've used it, I've barely touched the touchscreen.
The "Key Button Icon"—the explanatory icon showing "what will happen if you press the bottom physical button right now"—can be turned off in the settings if you don't need it.
The back of the unit.
The Karoo 3 came out after SRAM acquired Hammerhead, but it still doesn't have SRAM marking here.
This is "SRAM's Karoo," so it has SRAM markings.
The Hammerhead Shark sticker—the adorable hammerhead shark—is not part of the default specifications, just so you know.
The small hole in the image was surrounded by a circle on the Karoo 3 with "BEEP" (electronic sound) marked on it to indicate it was a sound-producing hole, but the SRAM Karoo has no such marking.
Once you're in the ride program, if you long-press any point on the map, you can separate your consciousness from your current location (I'm using that term loosely), and from there if you tap another point on the map, you'll be asked whether you want to start navigation to that point or just place a landmark pin.
If you select navigation, a beep sounds
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