ROCKBROS Heavy-Duty Steel U-Lock | Emoto and E-Bikes

The ROCKBROS Heavy-Duty U-Lock combines a vacuum heat-treated steel shackle, dual-sided locking design, and protective silicone coating for dependable everyday security. Its compact 8.27 x 4.33-inch size makes it practical for commuting while still providing room to secure a compatible bike frame to a rack or other fixed object.

The shackle has a maximum stated diameter of 22mm and is designed to resist common cutting and prying attacks. At 1.76 pounds, or 0.8kg, the lock provides substantial steel construction without becoming overly difficult to carry on daily rides.

Protected High-Security Lock Core

The precision-engineered lock core uses a unique key design intended to resist picking and other technical opening methods. A built-in dust cover helps keep dirt, water, and road debris away from the cylinder, supporting smoother operation and a longer service life.

A thick silicone exterior helps protect the lock from daily wear while reducing the chance of scratching the bike’s frame. The included mounting bracket secures the lock to a compatible frame tube for convenient transport.

Technical Information

• Brand: ROCKBROS
• Lock type: Heavy-duty bicycle U-lock
• Locking design: Dual-sided security
• Primary material: High-quality alloy steel
• Steel treatment: Vacuum heat-treated
• Maximum stated shackle diameter: 22mm
• Lock dimensions: 8.27 x 4.33 inches, or 21 x 11cm
• Weight: 1.76 pounds, or 0.8kg
• Lock core: Precision-engineered cylinder with unique key design
• Keyhole protection: Protective dust cover
• Exterior protection: Thick silicone coating
• Transport: Bicycle mounting bracket included

Fitment

• Suitable for compatible road bikes
• Suitable for compatible mountain bikes
• Suitable for compatible e-bikes and commuter bikes
• Can also secure compatible gates, fences, and other valuables
• Confirm the lock opening and mounting bracket fit your bike before ordering

Why It Stands Out

The 22mm vacuum heat-treated steel construction provides a strong physical barrier, while the dual-sided locking design and precision cylinder add protection around the locking mechanism. A silicone coating, dust cover, and frame-mounted carrying bracket make the lock practical for frequent outdoor use.

No bicycle lock can stop every theft attempt. For better protection, secure the frame to a solid fixed object, keep the lock away from the ground, and leave as little open space as possible inside the shackle.

Best For

• Urban commuters securing a bike during everyday stops
• E-bike owners who want a substantial steel U-lock
• Road and mountain bike riders who prefer frame-mounted lock storage