TMD’s redundant bike lock is a $280 solution to a $60 problem

I’ve seen a lot of so-called “smart” bike locks over the years, but none so far that would justify the extra cost. A new start-up in bank ATMs is trying to change that. Nothing too special TMD Chain Lockbut the combination of hardware, functionality, and insurance coverage of the ART-2 makes it worth considering.

TMD’s first bike lock combines a Bluetooth proximity sensor and motion alarm with a thin metal frame wrapped in soft and lightweight Dyneema and Kevlar fiber sleeves. This makes the lock strong, yet still able to wrap around your seat when riding a bike. TMD also designed a keyless lock that can be shared with friends and family, as well as withstand shock, rain, dust, and high temperatures. This makes it very suitable for city bikes parked outside and ridden all year round.

I like the TMD Chain Lock I’ve been testing, but spending €249 (about $283) for something that usually costs less is a big ask.

The noise separating ATM security from bicycle security is not as far as it might seem. TMD created a centralized, redundant system for banks to allow access to its ATMs to operate, instead of master keys that create a major security risk whenever they are lost or stolen. I know exactly what TMD is bringing to the Bluetooth bike lock.

There are many benefits to turning phones into digital keys, especially in bike-centric communities like the Netherlands, which TMD calls home. For example, I can ride to the train station and ask a trusted friend to pick up the bike later. And the trivial simplification adds up quickly for those of us who use our bikes to get to work, pick up the kids at daycare and soccer, run errands, and buy groceries. In my home city of Amsterdam, it’s not unusual to have to grab my keys several times a day to lock and unlock my bike.

I tried TMD Bike Lock in 110cm (about 3.5 feet) is the iPhone 15 Pro with the latest version of iOS. Most of the time – I’d say 19 out of every 20 attempts – the TMD Chain Lock instantly recognized my method, allowing me to unlock it seamlessly with just the push of a button. As I waited, it didn’t take more than a second for the button to flash blue, indicating that the lock had detected my nearby phone in a pocket or purse. Great, but that flexibility comes with tradeoffs.

For example, my bike was in the middle of my phone when I parked it outside a cafe, so anyone could get on it and open it. I had the same issue when cooking in my kitchen with the bike parked outside the window, as I do. In both cases, I had to move the bike or turn off my phone’s Bluetooth radio. And since my phone is now my bike key, if it’s stolen, my expensive e-bike is dangerous.

TMD claims its Chain Lock is “the ultimate protection against drilling and picking,” but all bike locks can be defeated by a determined thief. The Chain Lock has received ART-2 certification from an independent Dutch organization that tests and certifies bicycle locks on a scale from one to five. Most Dutch insurance companies require ART-2 at least to insure policies for expensive e-bikes and cargo bikes. It is similar to other such as Selling Safe Silver or Gold in UK, 2 Roues in France, and VdS approval in Germany. (The US and Canada do not have a single, centralized, independent testing body that defines bike insurance requirements.) If your bike is stolen, you can create a digital file for the insurance company from within the TMD program as legal proof that your bike is covered.

To prevent theft, the lock also has an integrated alarm that can be armed and disarmed in the app or by double pressing the lock button. At 100dB it’s a bit quieter than I expected, but it does the job when it feels like the lock is moving. It turns itself off after about 10 seconds of inactivity.

The lock is very noisy in daily use. The opening is accompanied by a loud sound that hits 75dB when measured at a distance of one meter. I hate that it takes away my attention and my expensive online bike. It’s just green and open – that’s enough. TMD tells me that future updates will allow you to disable these sounds.

TMD claims the lock’s battery can last up to nine months on a single charge. However, my test unit has already dropped 16 percent after a week of testing, which means that the lifespan is closer to six or seven weeks. But maybe that’s because I keep my bikes inside my house when not in use, so the Bluetooth lock radio is always activated by the proximity of my phone.

To prevent water and dust ingress and leave more room for the battery and speaker, TMD says it chose a non-magnetic connector – not USB-C – to charge the Chain Lock. It’s a shame because most phones have USB-C ports and offer better quality IP68/69 protection against rain and debris. This means you should have a cable to connect the lock when you ignore the low battery warnings and leave it to us. It can recover quickly, though: I’ve seen a dead (and locked) Chain Lock come back on after two or three minutes of turning off the iPhone’s USB-C port.

You can still unlock TMD Chain Lock when your phone is dead. You just need to press your four digit “emergency code” again on the lock button. Selecting a code like 1324 would require pushing 1, then 3 pushes, then 2, and 4. The ring around the button changes colors to show you the new number. The TMD app also allows you to share the lock with friends and family, who can also help you with their phones.

For peace of mind, it’s always a good idea to double lock your bike, so many urban cyclists combine a lock with a ring lock that is mounted on the frame and prevents the rear wheel from spinning. TMD has already announced “Anti angle grinder” U-Lock and Equipped with GPS rings coming later this year. Having my phone unlock all my bike locks at once would make it easier and justify the TMD prices.

Right now, pay € 249 while similar bicycle analog locks cost a quarter of that would be ridiculous for most people. ART-2 has been confirmed ABUS 8900for example, in the same flexible length of 110cm, it costs about €60 (about $68). If you can buy a TMD Chain Lock and hate keys, or want a keyless lock that can be shared digitally, give it a try. Otherwise, it will not justify its high price.

All photos by Thomas Ricker / The Verge