The OnGuard RockSolid 8580 is a Sold Secure Diamond-rated lock that is claimed to resist angle grinders making it ideal, in theory at least, for securing high-end road, gravel and electric bikes.
OnGuard may not be the most recognisable brand in bike locks, but it operates as a subsidiary of Magnum Locks, a large industrial firm that’s focused solely on security. This relationship gives OnGuard access to a broad range of expertise and manufacturing techniques. Leveraging this specialisation and advanced knowledge, OnGuard has developed what it says is "an impenetrable fortress against even the most determined thieves”.
Construction
At its core lies a 15mm hardened steel shackle coated with OnGuard’s patented RockSolid finish, which is the basis of this remarkable lock's effectiveness—more details shortly. Weighing only 1.3kg/2.8 lbs, the RockSolid features a shackle reach of 17.5cm/6.8 inches and an internal width of 9cm/3.5 Inches, resulting in a locking area of 157 cm2/23.8 Inches. This makes the OnGuard the lightest in our tests by almost a kilo, although it also offers the smallest locking reach.
The main body attaches to the shackle using OnGuard’s X4P Quattro four-point locking system, secured by an enhanced Z-Cylinder lock barrel that’s designed to resist picking, pulling, and drilling. OnGuard provides five keys, the highest number among all the angle-grinder-resistant locks we’ve tested. To protect against the elements, the RockSolid features an automatic key cover and a robust rubberized coating to maintain its appearance.
Specification
In Use
On receiving the RockSolid, I immediately noticed its quality. The rubberized coating is soft yet not tacky, with minimal play between the shackle and locking mechanism. This secure connection is evident when removing the shackle, which requires a slight jiggle to disconnect. While this adds to the impression of security, it can be frustrating, as rushing makes alignment difficult. Simply slowing down resolves this issue.
This minor frustration extended to engaging the key a couple of times. While the automatic weather guard is a nice touch and utterly unique to OnGuard, getting the key to engage with it isn’t always straightforward. Once engaged, the lock was smooth, positive, and consistent across all keys.
In the wild, I was never troubled by the RockSolid’s lack of reach, but that could be because my local town is not a central transport hub or commuter hotspot, so there’s always room at a bike rack. I know how busy transport hubs in New York, London, and Manchester can be, and I see that as an issue for some, especially if you need to secure your bike to a lamppost or railing.
The Angle Grinder Test
This is where the OnGuard RockSolid solidified its status as my choice for best overall. By pure coincidence, the OnGuard was the last to be cut on the day, and its resilience took me by surprise. During our five-minute test, we used a high-powered battery-operated angle grinder fitted with metal-specific disks, and the OnGuard showed barely a scratch. The patented RockSolid coating that’s applied to the 15mm hardened steel shackle effectively ‘sanded down’ the cutting disc, launching plumes of grinder disc dust into the air.
In well under the five-minute time limit, we burned through three grinder discs, the most of any lock on test. To this point, all the locks were cut to some depth into the shackle within the time allowed.
Value and conclusions
Given the OnGuard RockSolid's security against angle grinder attacks, you may be surprised to learn it is the cheapest in our test at £200/$250. That’s £50/$50 less than the next cheapest, the Litelok X3, and a massive £100/$100 less than the Hiplock DX1000.
While I am awarding the OnGuard the title of best overall angle grinder-resistant lock, it could also be the best budget, most secure, and most user-friendly lock. This shouldn’t reflect badly on the other locks in the test, as they all performed well. None failed the angle grinder test, and all offer similar specs and retail prices. The OnGuard RockSolid, like Tadej Pogacar, stood out in a field of outstanding performances, having that little extra something to give.
How we test - angle grinder locks
While watching sparks fly and examining a bike lock's construction more closely is fascinating, most videos and reviews of angle grinder-resistant locks do not represent the real-world scenario. In reality, thieves don't have half an hour or time to swap out worn-down cutting discs.
After many hours in a YouTube black hole, my research showed that opportunistic bike thieves really have less than a minute. After this, someone arrives on the scene with a phone filming the incident or attempting to get the thieves to stop. In some cases, the police are called and will be on their way.
So, I devised a very simple test.
To remove a bike lock with an angle grinder, you need to either make two clean cuts, one through the shackle and one through the lock barrel, or one cut through the shackle and be able to twist the lock. Since most locks now feature anti-twist and tamper features, I would likely need to make two clean cuts.
Using a high-powered battery-operated angle grinder fitted with high-quality metal-specific cutting discs, I allowed myself a maximum of five minutes. This would account for any disc changes required and be more representative of the time a thief may allow themselves in a low-foot traffic area, or if they had broken into a shed or garage.
