The OnGuard RockSolid U-Lock is engineered for riders who demand advanced protection against modern theft tools. Built with a 14 mm (0.55 in) TriRadius hardened steel shackle and a proprietary angle-grinder-resistant coating, this lock helps resist cutting wheels, saws, and leverage attacks used by determined thieves. The X4P Quad Lock mechanism secures the shackle on four sides to prevent spreading, twisting, or forced separation under attack. Its balanced 90 mm × 175 mm (3.55 in × 6.90 in) interior dimensions provide secure locking around racks and posts while minimizing leverage space. Despite its extreme strength, the lock remains portable for daily commuting and high-risk urban environments.

• Angle-Grinder Resistant Coating: Specialized exterior layer helps disrupt cutting wheels and significantly increases resistance to grinder-based theft attempts.
• X4P Quad Lock Security: Four-sided locking mechanism secures the shackle at multiple points to resist prying, twisting, and forced separation attacks.
• 14 mm (0.55 in) Hardened Steel Shackle: High-strength TriRadius steel construction resists bolt cutters, leverage tools, and sawing attempts.
• Balanced Anti-Leverage Design: 90 mm × 175 mm (3.55 in × 6.90 in) interior dimensions reduce available leverage space while securing bikes tightly to racks or posts.
• High-Security Urban Protection: Designed for high-risk areas and valuable bikes including e-bikes and commuter bikes needing advanced theft resistance.


Manufacturer Sku: 8590
Todson Sku: 45008590