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  • ¥14,160
  • Regular price ¥17,700

30 days of free service

Customer Reviews

Based on 22 reviews
AlterLock Review (campaign reviewer)

The AlterLock is so simply to use and connect to your bike and give you great peace of mind. I now feel alot better about leaving my bike locked up outside knowing that AlterLock will alert me and then allow me to search for my bikes location if it was ever to be stolen.

Great Product for a suburban area (campaign reviewer)

Depending on their location and bike usage, I live near the outskirts of London. It suits my needs quite well. The tracking only updates when the bike has stopped, so I would not recommend the product for areas like the city of London or some high-crime surrounding regions. If the thieves in your area are not as bold or cunning, this is a great product. My advice for the city of London riders would be to get a rented bike rather than using your own; if a thief wants your bike, they will take it, and most are wise to trackers on the market anyway. I once had a motorbike stolen with a minimoto tracker under the seat; the thief took it round the corner, removed the bike seat, and discarded the tracker. But london is a hard area to keep anything safe, if you live in an area like horsham, this tracker should be perfect for you.

Alterlock sent me the alternative lock for testing. (campaign reviewer)

The installation of the app under Android from the app store was done quickly, and with a normal mount for the bottle cage, the installation under the bottle cage would also have been done quickly and easily.
For my special bottle cage mount, the included M5x16mm screws were a little too short.
About setting up the lock in the app:
Since the app unfortunately does not allow pre-taken pictures of the bike, and also the setup can only be completed with a picture, it is best to do the initial setup during the day and near the bike.
The recommended firmware update didn't work for me, but the lock still works perfectly.
The battery life is certainly not too short, in the course of the test of 2 weeks the battery level in the app dropped by one of three bars.
I can't judge whether or not the lock will send a thief running when the alarm is triggered, and how long it will take for the thief to remove the Alterlock. But for parking at the bakery or on a bike marathon it is a good investment in any case, light and inconspicuous, and sensational when the alarm goes off.

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Prevents theft and tampering.

Bike: De Rosa Protos and others

After my Pinarello Dogma was stolen, I started using AlterLock to prevent theft and tampering. Awareness is the key to prevention. I’ve installed AlterLock on all my bikes.

I was so relieved my bike was saved!

Luka Pyon
Bike: Merida Reacto 8000-E

I saw someone checking out my road bike, but I was too far away to do anything. He pulled a tool out of his pocket and broke the lock. However, AlterLock detected the vibration and sounded the alarm, scaring him off.

It's great to have security and peace of mind.

Bike: Specialized Venge Pro

I bought AlterLock after hearing the buzz about it. I used to have a standard wire lock and was worried about leaving my bike while shopping at the convenience store. With AlterLock’s excellent security, I now have peace of mind. It’s rock-solid dependable—no doubt about it!

All three road bike concerns are covered!


  • Worried if even the most robust locks will be enough to protect it?


  • Worried about leaving your bike unattended—even for a short time?


  • Afraid to take your eyes off your bike for even a moment?

Why AlterLock?


Alarms & Notifications


Smartphone notifications


Monitor via Bluetooth


GPS & WiFi Tracking


Fine Controls


Small, Lightweight, and Inconspicuous

App Features

  • ・Register your bike's photo, specs, and VIN number
  • ・Toggle the device lock mode
  • ・Device settings (for various situations including vibration detection level, alarm on/off, alarm duration, first alarm sound, number of alarms, regular transmission, etc.)
  • ・Push notifications and audible alarms when the device detects vibration or receives location information
  • ・View location and history while tracking on the map screen
  • ・Tracks maintenance history for safer riding
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Easy Installation


Install the app


Subscribe to Cycle Guard Service


Register your bike and device in the app


Attach the device

Device Specifications

Size 159mm long x 38mm wide x 9mm thick
Weight 50g
Battery Lithium polymer
Charging terminals USB Type-C
charging cable not included
Temperature Operating Temperature -20~60℃⁣⁣⁣⁣⁣⁣
Chargeable Temperature 0~45℃
Uptime Up to 1.5 months⁣⁣⁣⁣ (varies according to usage)
Communications Bluetooth Low Energy / Sigfox
Location Tracking GPS (GNSS) / Wi-Fi
Water/Dustproof IP66
Accessories Start guide, 2 mounting bolts
Options 2 anti-theft bolts, special tools
*Only sold in sets with the device


Product Price €134.99/£114.99(tax included)
Service Fee £3.49/month,£34.99/year(tax included)
€3.99/month,€39.99/year(tax included)

Communication Areas

AlterLock transmits data via Sigfox (the LPWA communication standard) when outside of Bluetooth range. LPWA makes it possible for the device to communicate on its own with low power consumption and low cost. Since Sigfox has different communication bands in different regions, Alterlock comes in several editions.

The European version is available in the following countries: Belgium, Croatia, Czech Republic, Denmark, France, Germany, Hungary, Ireland, Italy, Luxembourg, Portugal, Slovakia, Spain, Netherlands, United Kingdom and Finland.


Can AlterLock be installed on any bike?

It can be attached to a standard sports bike using its bottle holder's base or in conjunction with your existing bottle holder.

What areas can I use this service in?

It can be used within Sigfox's service area (primarily Europe). Outside the service area, all functions will work within the Bluetooth transmission range. You can check the service area from this page.* Even within the service area, notifications may not reach your smartphone indoors where the signal is weak or in an environment with poor reception.

How is AlterLock different from Bluetooth trackers?

Bluetooth trackers are challenging to track once they leave your hands. AlterLock has stand-alone communication and GPS, so you can track your device wherever you go.

Can I check my location anytime?

This product is designed specifically for theft prevention. It cannot be used as a GPS tracker that continuously displays location information. Vibrations made in lock mode activate the GPS to significantly reduce power consumption and enable long-term tracking.

Can the device be removed easily?

If you try to remove the device, AlterLock detects the vibration and sounds an alarm to notify you, so you can rush to your bike. If you're still concerned, an additional anti-theft bolt and special tool are available. Please consider purchasing the device as a set. These items are not sold separately.

Is it possible to adjust the volume of the alarm and the sensitivity of movement detection?

Yes, it is. The movement detection sensitivity can be set to one of three levels.

Proudly engineered in Japan