AlterLock Gen2
Alarm, monitor, and track your bike.

AlterLock is an alarm/GPS tracking security device for bikes. It lets you keep a remote eye on your bike and notifies you on your phone when the device detects movement while the bike is locked away.

Main Features


If the AlterLock device detects motion from your bike while in Lock mode, it will blare out an alarm that is as loud as 95dB, which is louder than a lawnmower, almost just as loud as a helicopter.


When motion is detected, the AlterLock app will notify you on your phone with 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.


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. This can also provide clues if the bike is abandoned or when the police search for it.


Easy Installation

  1. Download and install the AlterLock app.
  2. Subscribe to the BicycleGuard Service.
  3. Register your bike and device in the app.
  4. Mount it on your bottle cage and turn the lock mode on.

Comparison with Bluetooth / GPS trackers

AlterLockBluetooth trackerGPS tracker
Movement detection alarm
Smartphone notifications– *1
GPS tracking after theft– *1
Real-time GPS tracking
Battery life
The size of the device
Mounting on road bikes
Comparison with general products.

*1. Only within bluetooth range

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.

Tech Spec

Size: 159×38×9mm
Weight: 50 g
Battery type: Lithium polymer
Battery life: up to 1.5 months/charge *1
Charging Socket: USB Type-C *2
Operating Temperature: -20 to 60°C
Charging Temperature: 0 to 45°C
Communication: Bluetooth Low Energy / Sigfox
Tracking: GPS (GNSS) / Wi-Fi
Protection: Water/Dustproofing IP66
*1 Varies according to use
*2 Charging cable is NOT included

1) Start Guide,
2) 2 regular mounting screws,
*Our package does not include a charging cable inside.

Other Options
2 security screws, a special tool
*Only sold together with the device

Phone App


To see if the area you are trying to use AlterLock is within the range of Sigfox,
please visit this page.

The European version is available in the following countries:
Austria, Belgium, Croatia, Denmark, Estonia, Finland, France, Germany, Greece, Ireland, Italy, Latvia, Lithuania, Luxembourg, Netherlands, Poland, Portugal, Spain, Ukraine and United Kingdom.

The Japan version will only be available in Japan.