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

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