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

I’ve seen a lot of “smart” bike locks over the years, but none so far can justify the extra cost. A newcomer to ATMs in banks is trying to change that. There’s nothing completely unique about the TMD Chain Lock, but the combination of materials, functionality, and ART-2 certification that comes with insurance make it worth considering.

TMD’s first bike lock combines a Bluetooth proximity sensor and motion alarm with a thin nose of a tough steel chain wrapped in a soft and lightweight sleeve of high-performance Dyneema and Kevlar fibers. That makes this lock heavy, but flexible enough to wrap around your seat when cycling. TMD has also designed a keyless lock to be shared with friends and family, and can withstand shock, rain, dust, and high temperatures. That makes it ideal for city bikes that are 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 a lot less is a big ask.

The gulf that separates ATM security from bicycle security is not as wide as it may seem. TMD developed a centralized, keyless system for banks to authorize access to their ATMs for service, instead of large portable keys that created a major security risk whenever they were lost or stolen. It’s this same keyless approach that TMD now brings to Bluetooth bike locking.

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

I tested the TMD Bike Lock at 110cm (about 3.5 feet) with an iPhone 15 Pro running the latest version of iOS. Usually – I’d say 19 out of 20 attempts – the TMD Chain Lock quickly recognized my approach, allowing me to unlock it seamlessly with a single press of the lock 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 found my phone nearby in a pocket or bag. It’s great, but that convenience comes with some trade-offs.

For example, my bike was always within range of my phone when it was parked outside a cafe, so anyone could walk up and open it. I had the same problem when I was cooking in my kitchen with the bicycle parked outside the window, as I usually 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 also at risk.

TMD says its Chain Lock is “resistant to common drilling and picking,” but all bike locks can be defeated by a determined thief. Chain Lock has received the ART-2 certificate issued by an independent Dutch organization that tests and certifies bicycle locks on a scale from one to five. Most Dutch insurance companies require ART-2 as a minimum to insure policies for expensive e-bikes and cargo bikes. It is similar to something like the Safeguard Silver or Gold standard in the UK, 2 Roues in France, and the VdS approval in Germany. (The US and Canada do not have a single, central, independent testing organization that sets bike insurance requirements.) If your bike is stolen, you can generate the insurance company’s digital log file 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 from the app or by double-pressing the lock button. At 100dB it’s a bit louder than I expected, but it does the job when it feels the lock is locked. It turns itself off automatically after 10 seconds of inactivity.

The lock is noisy in daily use. Turning it on is accompanied by a loud tone that hits 75dB when measured at a distance of one meter. I hate that it draws attention to me and my expensive e-bike. Just flash green and turn on — that’s more than enough. TMD tells me that a future software update will allow you to disable these sounds.

TMD says the lock’s battery will last nine months on a single charge. However, my test unit has already dropped 16 percent after a week of testing, suggesting a lifespan closer to six or seven weeks. But that’s possible because I keep my bikes in my house when they’re not in use, so the lock’s Bluetooth radio is always 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 shallower pin connector — not USB-C — to charge the Series Lock. That’s a shame because plenty of phones have USB-C ports and offer even better IP68/69 protection against rain and debris. That means you’ll need to have a proprietary lock cable if you ignore the low battery warnings and let them die. It can be quickly recovered, however: I’ve seen a completely dead (and locked) Chain Lock come back to life after just two or three minutes of charging through an iPhone’s USB-C port.

You can still unlock TMD Chain Lock if your phone dies. You must click the four-digit “emergency code” on the lock button. Selecting a code like 1324 would require pushing 1, then 3, then 2, and 4. The ring around the button changes colors to show you each new number. The TMD app also allows you to share the lock with friends and family, who can help you with their phones.

For added peace of mind, it’s always a good idea to double-lock your bike, so many urban cyclists combine a key chain with a lock that’s permanently attached to the frame and prevents the rear wheel from spinning. TMD has already announced an “anti angle grinder” U-Lock and a GPS-equipped Ring Lock coming later this year. Having my phone unlock both my bike locks at the same time would increase the convenience and better justify the TMD prices.

Right now, paying €249 when equivalent analog bike locks cost a quarter of that would be silly for most people. The ART-2 certified ABUS 8900, for example, in a flexible length of 110cm, costs about €60 (about $68). If you can afford the TMD Chain Lock and really hate locks, or need a keyless lock that can be digitally shared with others, have at it. Otherwise, it will not justify its high price.

All photos by Thomas Ricker / The Verge