AlterLock Bike Alarm Review

Not so much a lock. A smart alarm!

So Nextscape made a bike alarm. Now, you probably never heard of Nextscape. And that’s neither your fault, nor theirs. They’re an IT Solutions Provider from Japan. But some time ago they made a bike alarm. And now they released version 2. And they’re going world wide now.
For full disclosure: AlterLock did sent me this product to write about it, but just like you, AlterLock’s people are reading this review for the first time after I publish it. And to be honest, this is my first Bike Alarm review. So it’s new for all of us.
The quickest introduction on the AlterLock is this 19 second video:

It’s an alarm that mounts to your bike on your frame at the bottle cage and has built in GPS, BLE, WiFi and a “0G data” connection. Which means that even when it’s outside of Bluetooth range, you can still track it.

The AlterLock transmits data via Sigfox when outside of Bluetooth range. Sigfox makes it possible for the device to communicate on its own with low power consumption (this is the “0G data”). Since Sigfox has different communication bands in different regions, AlterLock comes in several editions, so if you’re moving-moving, going to KONA from Europe or something, keep that in mind. I’ll explain more about Sigfox later on.

In the Box

The box is nice and small, a smart online retailer will be able to ship it to you so it fits in your letterbox. AlterLock sent it to me in a big envelope. And had it not be for some customs declarations signatures, it could have been dropped in my letterbox.
Then inside the box you’ll obviously find the AlterLock itself, two screws, two USB-C port plugs, a quick installation guide and “important matters” booklet. I always find it entertaining that the documents labeled as important are the first to be discarded. Things are simple. I like that.

I was really struggling with the light conditions during the photo-shoot session of the box contents. I was outside and the sun was all over the place, as were the clouds. It changed every five seconds!

Technical Specs

For the weight weenies and general tech specs enthousiasts (is that a thing?) here’s a list:

Size159 x 38 x 9mm thick
BatteryLithium polymer
USB Type-C (charging cable not included)
Operating Temperature -20~60℃ (-4 ~ 140 °F)
Battery lifeUp to 1.5 months
CommunicationsBLE, WiFi, Sigfox
Location TrackingGPS (GNSS)
Water / Dustproof ratingIP66
AccessoriesStart Guide, 2 mounting bolts
Optionional2 anti-theft bolts, special tools

Looking at the tech specs I think this should be good for just about everybody. 50g isn’t a lot of weight, I mean that’s what a Forerunner 945 weighs. Aan Edge 530 weighs 76 grams and an ELEMNT Bolt 60. So it’s not a massively heavy thing you’re hauling around.

However, I was surprised by the size of the AlterLock. And here’s why:
I have a Beagle. If you are familiar with Beagles, you know they tend to do their own thing. Especially when that bunny scent enters their hyper sensitive nose. Yeah I can run after her, but through thorny bushes and such, I’ll pass. So for those moments, I have a GPS tracker for her which has a similar functionality as the AlterLock. This GPS tracker is 51 x 41 x 15mm. A bit thicker, almost just as wide, but three times as short. And only weighs 35 grams. I do have to say that the battery life on it is much-much shorter: at around five days. So I hope that all that extra volume and the 15 grams are all battery. But it feels with smart algorithms on movement and a longer poll, that battery life can be extended to at least two weeks, or a month. I mean, it only has to be ‘on’ when the alarm is on.

Anyway, the whole size point might bee a moot point. As it fits snugly under your bottle cage. You don’t notice it much and aero-technically you won’t either.


What is interesting is that it is a type-C USB. That’s brilliant. DCR is going to love this stuff (DCR right now). However, what you’ll also notice is that’s the charging cable is NOT included. I mean, that’s a bit of a bummer. Charging a device mounted to your bike is going to be annoying. My bikes live in the garage. My USB chargers live in the house. I do have 2m long charging cables, because I ain’t doing arm yoga in my bed. I’m all about that comfort. Get yourself a 2m/7 feet (or longer) USB cable people. Not just to charge your AlterLock, to just improve your quality of life. Grab them from ali-express or wherever. They’re only a couple of bucks. That’s also why I’m bummed it’s not included.

Anyway, AlterLock explained that they thought charging can be done by battery packs. Because they actually expected you wouldn’t have an outlet close by. Now that’s a whole different approach which I kinda get.


Operating temperatures, I’m just going to take their word for it. I’m not some sadist setting up my precious bike in a sauna or freezer. Then it’s IP66 rated, so it’s fine in heavy rain and dust. Just don’t take it swimming. And the location technology is GNSS. What is GNSS? That stands for Global Navigation Satellite System. Which is commonly known as GPS. So overall, this is built to be outside and should operate for the majority of people.

Data Connection

So, the AlterLock features a Sigfox data connection. It can also connect over BLE, but the range of BLE is limited to about 300 feet (100 meters). So whenever Mr Baddy loads your bike in a van and races off, the AlterLock switches to the data connection for communication. Not saying Sigfox is the ultimate answer, as the coverage is not world wide and sometimes unexpectedly spotty. It’s great where I live, but quite limited in the US (at the moment). So see the coverage check here. But the Sigfox network is being expanded constantly, so what may not be covered today, could very well be in a couple of weeks, especially in more urban areas.

As you can see on the map, Europe has decent cover. Less in the mountains, but good around cities. Then the US has sparse cover, but that should continuously improve.

The Sigfox data connection is the reason you can track your bike ‘wherever’ it goes, but it’s also the reason that this alarm comes with a paid subscription.


Setting up your AlterLock is a simple task and you only do this once. I think the whole process costed me about five minutes. I don’t like to invest too much time in elaborately explaining the process if it’s straight forward. But I’ll go and explain some settings and app features which you’ll use more than once.

The App settings page (click for full view)

You can make the Alarm completely silent if you want, I can understand this as it does draw a lot of attention when it goes off. And it might increase your chances on a successful retrieval if you lose sight of your bike completely. An Alarm screaming at a thief might move them to remove and toss it. But the better option I’d suggest to use is the First Alert Sound. This is like a warning sound for the warning sound. Giving you a chance to ‘unlock’ the AlterLock before it wakes up the whole block.

Then you can limit the Alarm. By setting that, it will sound x times before it goes in silent mode. Your app will still be in “stolen” and you can track the AlterLock as you please. This is a nice option as, again, thieves might try to remove it faster if it keeps annoying them. If it’s silent it doesn’t bother them.

One thing in the settings which surprised me is the Low Battery Notification. This only works over Bluetooth. Which is a bit of a pity. Would this work over Sigfox, and your bike has been stolen, you would know to hurry up.

Mounting AlterLock

When talking to AlterLock I asked if they thought about different mounting options. The bottle cage mount is quite visible. So if you want to steal it, you can quickly remove the alarm and be off. To counter that they optionally provide two anti theft bolts. And they did consider other options or form factors, in your seat tube for example, but the insides of frames are all different, size is limited and the frame itself hinders the alarm’s signals.

The mount process is, as you would expect, super easy. I was done in maybe five minutes. The AlterLock comes with two extra long bolts to mount it. As your current bolts are probably too short because the AlterLock itself is 9mm thick. Remember that it sits between your bottle cage and your frame.

Now, before you start complaining about losing aerodynamics, AlterLock beat you to the punch. They actually used models to calculate the impact:

This is not like the ‘working conditions’ where I just take AlterLock’s word for it, but:

At a speed of 40 km/h, the Cd value is +0.00062. This is a difference of less than 0.01 seconds per hour.

I will have to take their word for it, as I lack the computer to calculate this stuff, and sadly I don’t own a wind tunnel.

My Bike was stolen!

Well, no. I mean, I stole it. And by stealing, I mean, I ‘locked’ it and moved it..
So let’s look at how this process works, this video works best with sound, because well, it’s an alarm.

If you paid close attention, you might be wondering why the GPS page didn’t load. And as I reviewed the footage, so did I. So I went back and tried it again, then left it outside for half an hour or so. It took a while to get a fix, as this was actually the first time I let it get a fix after unboxing. On later occasions it was much, much faster.

The whole experience with the AlterLock has been pretty good. The alarm is audible and I received notifications on my phone and my watch. From there on, it’s easy to open up the maps page and see exactly where your bike is. If it’s stationary, you can even send the location to Google Maps and then use that to navigate you to it via ‘Open the App’.

The Social Game

A great feature that goes slightly hidden in the ‘Update Info’ button is to actually share the theft. You can quickly share bike information to your .. clout. What I really love is that you AlterLock provides a Live map page you can share. So if you and others are searching for your bike, divide and conquer, you can share the location of your bike via a URL. Kinda like the LiveTrack on Garmin devices.

AlterLock Alarm Sensitivity

One place where your bike feels safe but isn’t perse, is on the back of your car. Example here. But, on the back of your car, your bike is moving, shaking etc. So to make sure you don’t get false positives and you van leave your bike on the back of your car and relax, you can set the alarm sensitivity. It ranges from 1 to 3. Where you’d use setting one on a bike rack, two in ‘normal’ conditions and three to alert on any movement. Having that third option could prevent thieves from stealing your lights for example. Or your bike computer. Stuff like that.


The AlterLock is an interesting new product, or product segment even. As said in my opening paragraph, it’s my first time dealing with a product like this, so benchmarking isn’t really possible. But I can definitely see the advantages to the device. If you do a lot of sportives, tours, or just like stopping for coffee. It can give you peace of mind. And that is its whole purpose. It’s not a deterrent, well, with the alarm, it sorta is. You don’t have to put it on a road bike, maybe your commuter if you have a really nice one. Or your tour bike. It’s universal.

There are some things which are quirky and some things that are clearly “version one”. But I don’t see those as an issue. This is a whole new product group and the UI/Flow hasn’t settled yet. That is something you can feel using it. Small little delays, or buttons that don’t seem like buttons. I do expect all this to settle, more users means more data. AlterLock is still actively developing the app and the firmware so it should all improve. And the overal use is good. Functionality is good and I’m a happy user.

Prices and Availability

The AlterLock sells via their own website and costs €135 or £115 on top of which you get a subscription for the data connection. At the time of writing it is available from pre-order at a decent discount (€99,99), with the expectation to ship at the end of May. These links are not sponsored.

EU €GB £
Purchase price€134.99£114.99
Service Fee / mo€3.99£3.49
Service Fee / yr€39.99£34.99

Sponsored Links

Just a note about the “links to buy” in this article, as they are sponsored. I do look for the lowest price I can find at the time of writing in a handful of stores, but by using the links I earn from qualifying purchases made through these links.

1 Comment on AlterLock Bike Alarm Review

  1. William De Ritis // August 30, 2021 at 1:56 pm // Reply

    Hello there,

    I sort of agreed with u in al most everything but the price is too high for something that isn’t 100% working correctly I had loads of bugs and problems with it and still have.
    locations wise is most of the times horrible is always on couldn’t find location especially when you need it most like indoor!
    the costumer service ? even worse!
    the all idea I think is revolutionary but they should either fix these problems or drops the prices I do understand that isn’t a startup but all of this bugs and problems and specially the frequences of it is like 2 times of 3 everytime you open the app. let me know what do you think.

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