OnGuard RockSolid 8590 - Best Value & Most Compact Angle Grinder Resistant Lock
The OnGuard RockSolid 8590 delivers astonishing angle grinder resistance in an incredibly light and compact package, offering top-tier security at a competitive price.
- +Exceptionally lightweight at 1.3kg (2.8 lbs) for a Sold Secure Diamond-rated lock.
- +Patented rubberized surface finish on the hardened steel shackle turns angle grinder discs to dust.
- +Often the most affordable option among high-end angle grinder resistant locks.
- -Smallest locking area on test, with limited internal space that may not fit bulkier e-bikes or certain locking points.
- -Lacks an included frame mount, making transportation less convenient.
- -Shackle diameter of 15mm is slimmer than some competitors, though its composite material compensates.
The OnGuard RockSolid 8590 stands out by defying expectations, combining extreme security with remarkable portability. Its most impressive feat is its weight—or lack thereof. At just 1.3 kilograms, it is significantly lighter than every other Sold Secure Diamond-rated lock in its class, some of which weigh over twice as much. This makes it one of the easiest high-security locks to carry daily. The secret to its performance lies in its patented RockSolid shackle, which features a hardened steel core coated in a specialized rubberized material. When attacked with an angle grinder, this coating doesn't just resist cutting; it actively degrades the cutting discs themselves. In testing, multiple grinder discs were worn down to nothing while making only superficial marks on the lock's surface.
This destructive interaction would be a major deterrent in a real-world theft attempt. The lock also features a robust, anti-pick and drill lock mechanism. The primary compromise for its low weight and cost is size. With a maximum shackle height of 17.5 cm and an internal width of 9 cm, it has the smallest locking volume of its peers. This requires more careful selection of locking points and may not accommodate very large bicycle frames or components. However, for standard road, hybrid, or mountain bikes locked to standard racks, its size is sufficient. For cyclists seeking the highest possible security without the burden of heavy metal, the OnGuard RockSolid 8590 is a compelling and often unbeatable value proposition.