Kryptonite Stronghold Anchor 6.10 lbs. - Permanent Locking Point for Use Indoors or Outdoors to Keep Bicycles; E-Bikes; Scooters Safe

This thing is huge. I found a large, heavy package on the porch and couldn't recall ordering anything that big or heavy. I thought, "What, 24 more cans of cat food?" The round black part is light plastic with two 4 mm holes: it provides a pleasant cover over the bracket you bolt do the ground. It comes with 5/16" and 5/8" concrete bits but my DeWalt 577 drill needs SDS+ bits, so I set those aside and bought two more bits for my collection. The instructions for anchoring this to the floor are clear, correct, and guide you through the work so you don't, as it warns, end up with holes all over the place. You drill on 5/8" hole, then a 5/16" pilot hole guided by the bracket, then bore out the 2nd hole to be 5/8", and repeat that for the final hole. I used a shop vac to get the concrete dust out of the holes. Two of the masonry anchors worked flawlessly, but the 3rd came apart in the hole. All pieces are magnetic, so I retrieved them and spent an hour trying to put them back together. No dice. I slept on it. The next morning I reassembled the fastener by building it around a 7/16" diameter rod (not the 3/8" bolt) and had it back in working order in 5 minutes. It came apart the first time because the hole was neither deep enough (off by 1/8") and it must have had a burr along one side. I know this now because the fastener came apart a second time. I fixed the hole, reassembled the fastener, and got it all done. It looks great. When I drive off and leave the door up I know that at least my bike will be there when I get back. Amazing how far you have to go to deter a would-be thief.Note: to reassemble the fastener I used 2 rubber bands, a 7/16" rod, and circlip pliers to spread the spring. Just saying.

I moved from the quiet suburbs to an active urban neighborhood. Lots of riders in the area, but I still didn't want to take any chances with theft. I did my research and essentially, the best form of security is something that anchors your bike to a solid object, so it cannot be simply loaded into a truck.I wanted piece of mind. I bought this, the 5 ft. Kryptonite chain, and the Kryptonite disc brake lock.Let me tell you about installation of this thing: It's not as bad as it seems, but you will most likely feel in over your head unless you've drilled through masonry before.YOU NEED TO USE A HAMMER DRILL.I looked up the price to rent one and noticed it was actually the same as buying one through Amazon, so I picked one up for $30. Kryptonite supplies two bits, which honestly were probably low quality, but they got the job done. You need to apply a lot of downward pressure to drill to the proper depth. You have to ensure that you've gone absolutely far enough, AND cleaned out the hole as best as possible, otherwise you'll hammer the bolt sockets into the sidewalk and realize they won't go all the way down. This would be a huge mess as the entire point of those sockets is to be secure against removal.Once you have drilled one hole perfectly, you can line up the base and drill the other two. Again, you have to be really sure that the location is good and that the holes line up.Assuming all goes well, the installation is actually not that bad. Really just take your time with the drilling, follow the instructions, and be prepared to get your hands dirty. The anchor is actually a very nice, clean looking piece once installed. I'm very happy to have a permanent locking location right outside my door. The overall investment is pretty minor when you consider the thought of losing your bike entirely, and the lengthy and costly process that entails.

This is bigger than it looks in the photos. Eight inches diameter and almost two inches thickness makes quite a lump on your garage floor or patio.Before buying this Kryptonite unit I had considered digging a little hole in the floor, pouring in some cement, sinking an eye bolt in that, and waiting for it to set and cure. But hardened eye bolts are hard to find. Nice strong forged ones, sure, but they're not hardened and are very saw-able. So I thought of buying a decent hardened chain and pouring the concrete over most of that, leaving just a few links sticking out. But the chain would cost more than this unit. So I ended up just getting this thing and not pouring any concrete.The included drill bits are good. I tried drilling first with my conventional 1/2" drill, and it worked for a while, but had a gawdawful time getting through whenever it hit a rock; and since I was drilling through concrete, of course there were loads of rocks. So I bought a Harbor Freight 1/2" hammer drill, the cheapest one (about $20). While nowhere near as substantial a piece of machinery as my faithful old non-hammer drill, it worked just fine. It needs some downward pressure but not an unholy amount; let the drill do the work. It took me no more than five minutes of actual drilling time to do all three holes. Your mileage may vary; there's concrete, and then there's concrete. Some concretes are more annoying than others.The inserts are designed to grab in a hole maybe 1.5" deep. My outdoor slab of concrete is thinner than that, not much over an inch. It was poured in the 1920s, when they perhaps weren't so profligate with even cheap materials as they are now. So all three holes went all the way through. While that certainly made it easy to clean the dust out - it all fell through the bottom - it wasn't obvious that there would be enough material for the inserts to grab. I went ahead anyway, and it all seems to have worked OK.A problem - it is essentially impossible to drill three holes in exactly the right places. This is true for all materials and is just the way that conventional drill bits work; when they start to cut they don't do it absolutely symetrically, and the hole wanders. Drilling one hole as a pilot and then widening it with a larger drill makes things even worse; both bits will wander off center when they start cutting, and you'll be even farther off. Which is one reason why in machine shop practice a drilled hole is not considered a high-precision feature. Reaming and boring are precision operations, drilling is not. So in general, holes drilled in concrete won't end up where you want them without spot drilling and some elaborate fixturing which this kit doesn't have. So my holes were off a bit. Actually, they were off rather a lot. I managed to get the screws all started anyway; start them all with the plate not touching the ground (don't tighten one, then expect to get the others to line up, because they won't). Once they're started they'll probably sock down OK. If it hadn't worked, I could have tried again, moving the whole thing a few inches to one side or the other ... or I could have done it the long way, hammering holes through the floor, digging three little pits (or one bigger pit), filling them with fresh concrete, putting coupling nuts, studs and washers in the wet concrete, and lining them all up with the plate before it sets. This method wouldn't use inserts at all. But as it turned out Plan B wasn't needed.The included "L"-shaped hex wrenches are hardly adequate. They fit fine but are just too small to get any decent leverage. I used hex bits and a 1/2" drive flex handle to really torque the lil' buggers down.The finished installation looks nice - about as elegant as one can expect a chain on a floor to be - and feels very solid.I replaced the two flathead screws with stainless ones - just ordinary hardware-store specimens, not hardened or high-strength. They just hold the plastic cover down; it's the three bolts sunk into the concrete which make this secure.My motorcycle seems happy with the whole arrangement, except for being outdoors, and we can't blame Kryptonite for that.