ONGUARDRockSolid U-Lock – Angle Grinder Resistant (3.5” x 6.9”) for Bicycle, Motorcycle, Powersport – 14mm Shackle, X4P Locking Mechanism, Lightweight, 5 Keys Included, Anti-Theft Protection

i dont think ill ever know if its making people think again but you know it doesnt matter just not having to worry about the bike is great and ive seen enough about this thing to have peace of mind with it soo ill add to the 5 stars xD

This review is for the OnGuard RockSolid Model 8590 Angle Grinder Resistant U-lock, one of the lightest angle grinder-resistant locks on the market with a Sold Secure Pedal Cycle Diamond rating. The OnGuard RockSolid 8590 is nearly 1.5 pounds lighter than my Kryptonite New York Standard lock, has a higher security rating, and incorporates a special diamond coating that can wear down cutting blades. I bought this lock because battery-powered angle grinders are now a prominent threat and can potentially make short work of previously Diamond or Gold-rated locks that lack protection. I use the OnGuard RockSolid 8590 in combination with a folding lock to protect my Tern QuickHaul, and it fits perfectly between the chainstay and rear wheel, but there is not enough reach to include an immovable object.Speaking of reach, the OnGuard RockSolid 8590 is advertised as having interior dimensions of 3.5" by 6.9" (90 x 175mm), but I only measured 83mm x 174mm (~3.3" by ~6.85"). While the 14mm diameter shackle (without the RockSolid coating) is average to slightly below average for the category, there's a very thick rubber layer around it, creating a roughly 25.5mm (1 inch) square. Putting the shackle through the spokes of a 20" or smaller wheel may be challenging. I measured the shackle thickness to be 15mm with the coating.It should be noted that while some reviewers and publications might mention the OnGuard RockSolid in the same breath as the game-changing Hiplok D1000, the Hiplok is also Sold Secure Diamond rated in the Powered Cycle category at the expense of being ~600g or ~1.3 pounds heavier. While the OnGuard RockSolid was also listed in the Powered Cycle category, it did not have a rating. This lock does not include a bicycle mount, but the light weight makes it easy to carry in a bag or attached to a rack. I lock it to the base of the Tern Clubhouse Mini while riding.Notes:1) The Quattro locking mechanism is not rattle-free. There is still a small amount of play between the shackle and the crossbar.2) OnGuard is very generous with its keys. You get five keys, though none have a light.

I’ve been using the OnGuard RockSolid lock since it came out on Amazon, and I’m really happy with it. The lock feels incredibly tough and well-made, with the 15mm steel shackle giving me confidence that my bike is safe. The design is easy to use, and I love that the keyway is covered to keep dirt and moisture out.It’s a bit heavy, but that’s the trade-off for such solid security. It’s also built to resist angle grinders, which is a huge plus. Overall, this lock gives me peace of mind, and I’d definitely recommend it to anyone who wants to keep their bike safe.