AlterLock CycleGuardService

How AlterLock Works

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All of AlterLock’s features are designed for your peace of mind.


You'll get notifications regardless of distance.

The AlterLock device automatically switches to Bluetooth over short distances and to Sigfox over long distances.


GPS and Wi-Fi tracking

GPS and Wi-Fi location finding enable long-term tracking whether your bike is being kept indoors or out.

Main features

Monitor Your Bike with Lock Mode

Go into Lock mode simply by opening the AlterLock app and tapping the control at the bottom of any screen. AlterLock will then protect your bike with a loud alarm if someone tries to steal it and with GPS tracking in the unlikely event they succeed. The long-life battery can last up to two months on a full charge.

The AlterLock gives you complete control over the AlterLock device. Among other things, you can turn Lock mode on and off, configure the alarm, and set the movement detection sensitivity. The app lets you control up to three devices.

If you have an iPhone or any Android phone that supports automatic Bluetooth connectivity, you can turn Lock mode on and off by pressing the button on the AlterLock device itself without opening the app. This means you can take a break from riding and be back in the saddle as soon as you’re ready to go again without the hassle of taking your gloves off or getting your phone out.

Alarms & Notifications

If the AlterLock device detects your bike is being moved while in Lock mode, it sounds a warning and sends a notification to your phone. If your bike is moved again, a loud alarm is triggered.

Alarms are highly effective in deterring theft, but you don’t have to worry about the embarrassment of a loud alarm being set off accidentally. AlterLock can be set to emit a relatively quiet warning sound the first time it detects your bike is being moved. If further movement occurs, indicating theft, the device sounds a loud alarm to scare off the thief.

The AlterLock app has its own notification sound, so you can distinguish it from other notification sounds like email and realize you need to get to your bike straight away.

Movement Detection for Multiple Scenarios

The AlterLock device features our proprietary movement detection algorithm. It monitors movement patterns and recognizes those that indicate someone is interfering with your bike. The device can be set to give optimal protection without false alarms regardless of how your bike is parked, from being propped up in a bike parking lot to swaying in a bike rack.

In the second-generation device, the movement detection algorithm has evolved dramatically. By analyzing the typical disturbances that occur in different parking situations, we’ve succeeded in reducing the number of false alarms caused by, for example, your bike getting bumped or shaken in a cycle rack.

Where there’s no likelihood of your bike being bumped or shaken accidentally, the system can also be set to react to even the slightest movement, which can deter someone interfering with or trying to steal items such as your lights.

GPS & WiFi Tracking

In the unlikely event that your bike is stolen, AlterLock can track it once a minute all the way to its final destination. If the bike is moved indoors where there is no GPS signal, the device uses Wi-Fi signals to determine its approximate location.

What sets AlterLock apart from many other tracking devices is its ability to track its location independently of your smartphone. By employing a highly accurate GPS module and Sigfox communication to connect to the Internet, the device transmits location information even it’s hundreds of kilometers away, unlike Bluetooth, which has a maximum range of about 100 meters.

The second-generation AlterLock device also uses Wi-Fi signals for positioning, increasing the possibility of determining its location even indoors, where there’s no GPS signal. This can also provide clues if the bike is abandoned or when the police search for it.

Smart Design

Designed with aerodynamics in mind, the AlterLock device can be mounted on the bottle cage bosses of most sports bikes. Better still, it can be discreetly installed under your existing bottle cage without spoiling the frame’s aesthetics.

It doesn’t detract from the design of the frame. It doesn’t compromise your bike’s aerodynamics. And it’s lightweight.

The AlterLock device is no wider than the downtube of most road bikes. The curve along the bottle cage ensures that aerodynamics aren’t affected. You can feel how light the device is when you hold it.

Communication system

The system automatically switches between Bluetooth for short-range communication and Sigfox for wide-area communication to ensure that notifications are always delivered to your smartphone.

Sigfox is based on a low-power, wide-area (LPWA) communication standard, enabling low-power communication over any distance in conjunction with the Internet. LPWA is attracting worldwide attention as a communication technology for the Internet of Things (IoT), which connects all kinds of devices and equipment to the Internet. By being one of the first to adopt this communication standard, AlterLock has created a small, lightweight device that can operate for an extended period at low cost.

You can find more information about the Sigfox service area here.

Comparison with Bluetooth / GPS trackers

AlterLockBluetooth trackerGPS tracker
Movement detection alarm--
Smartphone notifications -
GPS tracking after theft -
Real-time GPS tracking --
Battery life -
The size of the device -
Mounting on road bikes --

* Comparison with general products.

Differences from Bluetooth trackers

Bluetooth trackers use your smartphone’s location to track your device. They’re super-lightweight and consume very little power, making them ideal for searching for lost items at short distances.
AlterLock is equipped with stand-alone communication and GPS, so it can be tracked anywhere in its communication area.

Differences from GPS trackers

GPS trackers are perfect for recording travel routes because they acquire location information at regular intervals. However, because of this, GPS tracking has very high power requirements and often runs for only a few dozen hours before the battery is exhausted.
AlterLock uses GPS in conjunction with an accelerometer only in the event of theft, so it can be tracked for weeks.

Our commitment to aerodynamics

Nowadays, exceptional aerodynamic performance is the hallmark of a road bike. We’ve kept this in mind in designing AlterLock.
AlterLock is an anti-theft device, but it’s been improved in terms of size and aerodynamics so you don’t have to sacrifice your bike’s aero performance.
We’ve perfected a device that allows all cyclists, from beginners to pros, to focus on riding in the confidence that they’re not being slowed down.

At 40 km/h, the Cd value is +0.00062. That’s less than an extra 0.01 seconds travel time per hour.

AlterLock Action Flow

App Features

  • Register a photo of your bike together with its specs and serial number.
  • Toggle the device’s Lock mode.
  • Configure the device (for instance, movement detection sensitivity, alarm on/off, alarm duration, initial alarm sound, number of alarms, regular transmission).
  • Receive push notifications and audible alarms when the device detects movement or acquires location information.
  • View location and history while tracking on the map screen.
  • Track maintenance history for safer riding.
Download on the AppStore GET IT ON Google Play

Note 1: Compatible with BLE-enabled Android 5.0 and above and iOS 11 and above.
Note 2: You’ll find a list of verified compatible smartphones here .

Easy Installation


Install the app


Subscribe to the CycleGuard service.


Register your bike and device in the app


Install the device.

Device Specifications

Size159 mm long × 38 mm wide × 9 mm thick
Battery Lithium polymer
PortUSB Type-C
(charging cable not included)
TemperatureOperating Temperature −20 to 60°C
Chargeable Temperature 0 to 45°C
Uptime Up to 1.5 months
(varies according to use)
Communications Bluetooth Low Energy / Sigfox
Location TrackingGPS (GNSS) / WiFi
Water/Dustproofing IP66
AccessoriesStart Guide, 2 mounting bolts