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

I’ve looked at a lot of so-called “smart” bike locks over the years, but none could justify the extra cost until now. A newcomer who started off as ATM security for banks is trying to change that. There’s nothing entirely unique about the TMD Chain Lock, but the combination of materials, performance, and insurance-friendly ART-2 certification make it worth considering.

TMD’s first bicycle lock combines a Bluetooth proximity sensor and motion alarm with a thin core of hardened steel chain wrapped in a soft and lightweight sleeve of high performance Dyneema and Kevlar fibers. This makes this lock tough, yet flexible enough to easily wrap it around your seat post while cycling. TMD keyless locks are designed to be shared with friends and family and able to withstand shock, rain, dust and extreme temperatures. This makes it highly suitable for bikes parked outside the city and ridden throughout the year.

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

The gap separating ATM security from bike security is not as wide as it seems. TMD developed a centralized, keyless system for banks to authorize access to their ATMs for service, replacing physical master keys that posed a massive security risk if lost or stolen. This is the same keyless technology that TMD now brings to the Bluetooth bike lock.

There are many benefits to turning a phone into a digital key, especially in a bike-centric society like the Netherlands, which TMD calls home. For example, I can ride to the train station and ask an authorized friend to pick up the bike afterward. And the convenience of keyless adds up exponentially for those of us who use our bikes to go to work, pick up kids from daycare and soccer, run errands and buy groceries. In my hometown of Amsterdam, it’s not unusual to have to grab my keys more than a dozen times a day to lock and unlock my bike.

I tested the TMD Bike Lock at 110 cm (about 3.5 feet) in length with an iPhone 15 Pro running the latest version of iOS. Generally – I’d say 19 out of every 20 attempts – the TMD Chain Lock immediately recognized my approach, allowing me to seamlessly unlock it with a push on the lock’s only button. When I had to wait, it didn’t take more than a second for the button to flash blue, indicating that the lock had detected the phone near me in a pocket or bag. Great, but this feature comes with some changes.

For example, when my bike was parked outside a café it was in range of my phone, so anyone could walk by and unlock it. I had the same problem when I was cooking in my kitchen with the bike parked right outside the window, as I usually do. In both cases, I had to either ride the bike or turn off my phone’s Bluetooth radio. And since my phone is now my bike key, if it is stolen, my very expensive e-bike is also vulnerable.

TMD says its chain lock is “immune to conventional drilling and picking”, but all bike locks can be defeated by a determined thief. The chain lock has achieved ART-2 certification issued by an independent Dutch organization that tests and certifies bike locks on a scale of one to five. Most Dutch insurance companies require at least ART-2 to validate policies on expensive e-bikes and cargo bikes. This is something like a Sold Secure Silver or Gold rating in the UK, 2 Rouge in France and VDS approval in Germany. (There is no single, centralized, independent testing body in the US and Canada that sets insurance requirements for bicycles.) If your bike is stolen, you can generate a digital log file for the insurance company from within the TMD app as official proof that your bike was locked.

To prevent theft, the lock also has an integrated motion alarm that can be armed and disarmed in the app or by double-pressing the lock’s button. At 100dB it’s less loud than I expected, but when it senses lock movement it does the job. It automatically turns off after about 10 seconds of inactivity.

The lock makes a lot of noise in everyday use. When unlocked it produces a loud sound which reaches 75dB when measured at a distance of one metre. I hate that it draws attention to me and my expensive e-bike. Just flash green and unlock – that’s more than enough. TMD told me that a future software update will let you disable these sounds.

TMD claims that the lock’s battery will last for nine months on a single charge. However, after a week of testing my test unit has already dropped 16 percent, which suggests the lifespan is closer to six or seven weeks. But that’s likely because I keep my bike inside my house when not in use, so the lock’s Bluetooth radio is constantly lit by the proximity of my phone.

To prevent water and dust ingress and leave more room for the battery and speaker, TMD says it opted for a shallow magnetic pin connector for charging the Chain Lock — not USB-C. It’s a shame because plenty of phones have USB-C ports and offer better IP68/69 protection against rain and debris. This means you’ll have to keep the lock’s proprietary cable if you ignore the low battery warnings and let it drain. However, this can be recovered quickly: I observed a completely dead (and locked) Chain Lock reactivate after just two or three minutes of charging the iPhone’s USB-C port.

You can unlock TMD Chain Lock even if your phone is turned off. All you need to do is tap your four-digit “emergency code” on the lock’s button. Selecting a code like 1324 will require 1 push, then 3 pushes, then 2, and 4. The ring around the button changes color to visually prompt you for each new number. The TMD app also lets you share the lock with friends and family, who can also come to your aid from their phones.

For added peace of mind, it’s always a good idea to double-lock your bike, so most urban cyclists combine the chain lock with a ring lock that is permanently mounted to the frame and prevents the rear wheel from rotating. TMD has already announced an “Anti Angle Grinder” U-Lock and a GPS equipped Ring Lock coming later. Having both my bike locks open simultaneously from my phone would really increase the convenience factor and better justify TMD’s pricing.

Right now, paying €249 when the equivalent analog bike lock costs a quarter of that would be foolish for most people. For example, the ART-2 certified ABUS 8900 in the same flexible 110 cm length costs around €60 (about $68). If you can purchase the TMD Chain Lock and really hate keys, or need a keyless lock that can be shared digitally with others, do so. Otherwise, it won’t justify its exorbitant price.

All photography by Thomas Ricker/The Verge