How much do you hate keys? That's the central question behind TMD's new bike lock, a keyless chain lock that replaces physical keys with a Bluetooth proximity sensor and a smartphone app. Priced at $280, it is a significant investment compared to traditional locks of similar security levels that cost around $60. The lock aims to solve a problem that many cyclists face: the daily hassle of fumbling for keys, especially in bike-heavy cities like Amsterdam where locking and unlocking can happen dozens of times a day.
The TMD Chain Lock is not just a typical smart lock. It originates from a company that developed centralized, keyless systems for banks to secure ATMs. That background explains the lock's robust construction: a hardened steel chain wrapped in Dyneema and Kevlar fibers, designed to resist cutting and tampering while remaining flexible enough to wrap around a seatpost. It also carries an ART-2 certification, meaning it meets the minimum security standard required by many European insurance companies for expensive e-bikes and cargo bikes. In the U.S. and Canada, where no centralized testing body exists, this certification still signals a high level of protection.
The lock works by detecting your phone via Bluetooth when you approach. A simple push on the lock's button unlocks it. In testing, it worked seamlessly about 19 out of 20 times, with a delay of less than a second. This convenience is genuine for those who unlock their bike multiple times a day for commutes, errands, and child pickups. However, the proximity feature has a downside: if the bike is parked within Bluetooth range—say, outside a café or just outside a kitchen window—the lock automatically remains unlocked for anyone nearby. The only workarounds are to move the bike out of range or disable Bluetooth on the phone.
Another concern is that the phone becomes the key. If the phone is stolen, the bike becomes vulnerable. However, an emergency backup code (a four-digit sequence entered via button presses) provides access. Also, the lock can be shared with family and friends via the app, which is useful for scenarios like picking up a bike from a train station. The lock's integrated motion alarm, rated at 100 dB, deters thieves and can log events for insurance claims. But the lock emits loud unlocking tones (75 dB at one meter), which the author found annoying. TMD has promised a future software update to disable these sounds.
The battery life is rated at nine months, but real-world experience may vary. In testing, a week of indoor storage (where the phone is always in proximity) drained 16% of the battery, suggesting a lifespan closer to six or seven weeks. Charging uses a proprietary magnetic pin connector rather than USB-C, which is a disappointment given that many modern phones and devices use USB-C and achieve IP68 ratings. If the lock dies, a few minutes of charging can revive it, but carrying a proprietary cable is an added burden.
For anyone considering the TMD Chain Lock, the key question is value. A comparable traditional lock, such as the ART-2 certified ABUS 8900 in the same length, costs around $68. The $280 TMD lock offers keyless convenience, sharing capabilities, and an alarm, but these features come with trade-offs in range, noise, and charging. The lock is available in three lengths (70 cm, 110 cm, 160 cm) and three colors (Navy, Beige, Black). TMD also plans to release an anti-angle-grinder U-lock and a GPS ring lock, potentially allowing a complete keyless ecosystem.
For most cyclists, the premium is hard to justify. However, for those who absolutely hate keys, need digital sharing, or want insurance-friendly security with modern convenience, the TMD Chain Lock is a compelling but niche option. Its ATM heritage and solid construction mean it's not just a gimmick, but a serious product. Ultimately, it solves a real problem of key management, but at a price that many will find excessive.
The lock's design is sleek and does not scratch the bike's frame. The Dyneema and Kevlar sleeve protects both the lock and the bike. The thickness of the chain and the quality of the locking mechanism feel solid. The app is straightforward, though some users may find the constant Bluetooth scanning a battery drain on the phone. The lock's IP57 rating means it can withstand rain and dust, suitable for year-round outdoor use.
In summary, the TMD Chain Lock represents a significant step forward in bike lock technology, but it is not yet a mass-market solution. Its high cost and quirks limit its appeal to early adopters and those who value convenience above all else. For the average cyclist, a good-quality chain lock with a key remains a more sensible and affordable choice.
Source:The Verge News