Bicycle lock GERDA CONTRA chain lock 900 x 6 mm, hardened steel chain with protective sleeve

GERDA CONTRA chain lock 900 x 6 mm is a bicycle and scooter security device designed for everyday urban use. The product consists of a 900 mm long, 6 mm thick hardened steel chain covered by a protective fabric sleeve that reduces scratching and helps limit corrosion. The construction is intended to provide a visible and physical deterrent when securing a bike to racks, stands, railings or poles.

Advantages

The hardened steel chain increases resistance to cutting tools compared with non-hardened links, while the protective sleeve preserves frame paintwork and dampens metal-on-metal contact. Its 900 mm length offers flexibility for locking frames and wheels to fixed objects, and the compact cross-section makes it practical to carry without excessive weight. The simple form factor supports straightforward handling and quick deployment in daily use.

Suitable for

• Securing bicycles at bike racks and parking stands
• Locking scooters and e-bikes for short to medium duration stops
• Attaching a bike frame and at least one wheel to a fixed object
• Urban commuters seeking a portable, visible deterrent

When it may not be suitable

As a chain lock with 6 mm link thickness, this product is intended for everyday urban security rather than high-risk, long-term outdoor storage in isolated locations. It will not be fully resistant to professional-grade power tools or determined theft attempts using heavy cutting equipment. For maximum protection in high-theft areas, consider combining the chain with an additional lock or using a heavier-duty security solution.

Key specifications

• Chain length: 900 mm
• Link thickness: 6 mm
• Material: hardened steel chain with protective sleeve
• Protective sleeve: outer fabric to reduce scratches and exposure
• Intended use: bicycles and scooters, urban everyday locking

How to use

Wrap the chain around the bike frame and a secure fixed object such as a rack, stand or pole, passing through the frame triangle and at least one wheel when possible. Ensure the chain passes through rigid parts of the frame rather than quick-release components. Fasten the locking mechanism according to the lock type and keep the sleeve positioned to protect paintwork during handling. Store the chain on the bike or in a bag when not in use, and inspect the sleeve and links regularly for wear or damage.

What to consider before purchase

• Required security level relative to typical parking locations (short stops vs. long-term, high-risk areas)
• Compatibility of chain length with the objects you normally lock to (bike frame, wheels, fixed posts)
• Portability and weight for daily carrying

Usage recommendations

For improved security, use the chain in combination with a U-lock or disc lock to secure both frame and wheels, park in well-lit, busy areas, and avoid leaving the bicycle unattended for prolonged periods in high-theft locations. Regularly check the protective sleeve and clean or lubricate the lock mechanism to maintain function.