Nobody wants to lose their precious steed to an opportunist thief. Maybe you need a tracking device or alarm. Peter Maniaty takes a look at a product that incorporates both.
Nestling discretely between your bottle cage and downtube, AlterLock is a sleek Japanese-designed bike alarm with an integrated location tracker that provides alerts direct to your smartphone. Now into its third generation there’s a variety of alarm and motion sensitivity settings with a maximum volume of 95dB and alarm durations ranging from five to 60 seconds. Importantly, these can only be deactivated via the AlterLock app. Without access to your account, potential thieves can’t change them. The unit itself is compact and unobtrusive (167mm x 28mm x 9mm) weighing just 50 grams. It also has a solid IP66 ingress rating and claimed battery life of three months between charges.
How it works
Should your bike be moved whilst in ‘Lock’ mode, the AlterLock sounds an initial warning to get the attention of both the perpetrator and passers by, whilst also sending a motion alert direct to your phone. This makes it ideal if you’re leaving your bike unattended for a few minutes, say at a cafe or if nature calls. If the bike continues to be moved, its position can be tracked, indoors or outdoors, using a combination of GNSS (GPS & Galileo), Wi-Fi and 4G base station signals.
You also have the option of triggering louder and more annoying alarms to dispel any doubt that someone is getting shifty with your two-wheeled pride and joy.

Getting started
Set-up and registration is simple via the AlterLock app, whilst the unit itself is also very easy to install on your frame. However, given it screws straight in, my initial thoughts were “surely determined thieves can screw it straight out?”. To be fair, the AlterLock ships with anti-tamper security bolts that do make removal a little difficult. But it’s certainly far from impossible.
Another (albeit slightly counterintuitive) option is to intentionally deactivate the audible alarm – particularly when you’re away from your bike – given the AlterLock can still quietly track your bike’s location, allowing you and/or the police to make recovery plans without drawing the attention of thieves.
There was one other thing I noticed whilst installing the unit. The AlterLock’s slender shape isn’t especially compatible with oversized bottle cages, such as those fitted to my current road bike. Apart from leaving a large and unsightly gap between frame and cage, it was also tricky to access the recharging port. Mid-review I switched to a smaller bottle cage and had no more problems.
Pricing
Once you purchase the AlterLock Gen 3 (RRP $254.95) the motion alarm and Bluetooth-based notifications are free. However, to access longer-range connectivity and notifications using low power LTE-M and NB-IoT networks – and therefore enjoy the full AlterLock experience – you’ll need to subscribe to an additional service for around $60 a year.

Summing up
For me, the best feature of the AlterLock Gen 3 is undoubtedly the motion-based alarm with real-time phone notifications. Precise global location tracking sounds great, but given the unit can be relatively easily removed there’s no guarantee it will still be on your bike – unless you have the foresight to deactivate the audible alarm. Having used it for a month, AlterLock feels like a strong deterrent against opportunistic thieves, but less effective against more determined criminals. No, it’s not perfect. But it’s certainly better than nothing at all.
More info alterlock.net