Introduction: Bike Anchor Chain

By
About: Programmer by profession. Tinkerer of electronics. DIY junkie. I love working on my 100+ year old house with the crap ton of tools I have accumulated over 15+ years.

We park our bikes in our alley. Even though our alley has a gate and the bikes are not visible from the street, locking them up gives us more comfort: Just need anything to prevent a thief from quickly snatching a bike.

We had been locking our bikes to the gas pipe that runs along the alley, but:

  1. Don't want to mess with the integrity of the gas pipe.
  2. The pipe is too low and too close to the wall. It takes skill to find the right angle to run a bike lock through both the pipe and the bike frame.

So, I decided to build some bike anchors. Ruled out attaching anything to the ground because it would get in the way of snow shoveling during winter. So, I came up with a way to pretty decently attach a loop of really thick chain on our brick wall (could have used the concrete of the foundation as well).

Attaching a chain to a wall is not a big deal. The hardest part of the project was to decide on the readily-available parts to use for the simplest installation that would also be sturdy enough. This is where I landed after some thinking and after a failed prototype. Hoping that this won't turn out to be my second failed prototype.

The idea is not to make the stealing of our bikes impossible, but to make this a pretty hefty deterrent. Someone would need to have time to examine how the anchor is attached to the wall to be able to undo it. And if a bike thief has the time and tools and the courage to undo the anchor, so be it.

Making this anchor actually permanent is also possible by using anchoring cement or construction adhesive. I didn't want to take that drastic route because I made this as a prototype that I may want to undo and improve.

Supplies

  • Galvanized chain: 3/8" thick, 3' long
  • Anchor point: 1-1/2" (just the bracket is needed)
  • Concrete anchors
  • Hammer drill
  • Pen for marking + center punch
  • Screwdriver or ratchet depending on the concrete anchor being used
  • Screw covers
  • Silicone sealant (suitable for outdoors)

Step 1: Attach the Chain

Open the package of anchor points and separate the brackets from the D rings. You'll be using just the brackets. Make sure that the groove of the brackets is wide enough for a chain link to fit.

Mark the holes for a bracket. Because the chain I used was thicker than the groove of the bracket, I centered the bracket on the grout line between two bricks to gain more space.

Update: As several people pointed out if the holes are too close to the edges of the brick, it's easy to remove the screws by chipping the brick by hitting the screws or directly attacking the brick with a chisel. In my case, they're about 1/2" from the edges, which is too close. Ideally, you should keep the holes as close to the center of the bricks as possible. A larger bracket that allows the chain link to loosely fit would allow attaching the bracket near the center.

To make drilling more accurate, use a center punch to make small dents where your markings are.

Drill the holes.

Tip: If you're using Tapcon concrete anchors, make sure that the hole goes deeper than the screws to allow debris to be pushed in when you're screwing in the Tapcon. Or just blow out the debris after drilling. I usually use a bendy straw to blow into the hole.

Start attaching the first bracket by partially driving the first anchor. Don't go all the way because you need space to run the chain's end link through the bracket. Attach the chain and then fully attach the bracket to the wall.

Repeat for the other end of the chain, at a little distance from the first bracket. Make sure there's enough wiggle room for both ends of the chain.

Step 2: Conceal and Weather-proof the Anchors

Even though I drove in the Tapcons with a wrench pretty tightly, I didn't want a prospective bike thief to get any ideas by seeing the exposed heads (It would be easy to come back with a wrench or screwdriver on a follow-up visit.) I wanted to conceal the anchors to make the whole setup more intimidating.

Got some plastic screw covers that were bigger than the anchor heads and glued them on with a silicone caulk that is outdoors-resistant. This doubles as some rust protection for the anchors.

Update: Because the plastic screw covers are air-tight, the caulk that's trapped inside hasn't cured after two weeks. It's still very jiggly. This wasn't a great idea. The caulk will probably eventually cure, but maybe I could have punched a pinhole on the plastic cap to let it cure faster.