Bike Anchor Chain

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Introduction: Bike Anchor Chain

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.

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    19 Comments

    0
    spark master
    spark master

    10 months ago

    I like the concept, it keeps honest people honest. But grind off the edges and round the heads so they are not so easy to remove. As another has noted these are removable, so I humbly ask for people to consider a Double Expansion Shield. When putting 4 inch emt or 4 Inch gal we went with 3/8th size, but a 1/4 inch size would work here. You can slather it with pc-7 and then set it , Then after you set the outside nut it is simply not removable, after you put the hook on it (eyelet, welded steel ring of bibical proportion) you double nut it using permanant locktight or more PC-7. But first mash the outermost threads. We used these babies mounting huge steel enclosures, on ceilings. If you mount them on a stamped steel 1900 box It makes it very hard to attack the bolts. I would would use 2 or even 3 so I got them in center of the bricks. Again we used them with heavy electrical items and pipes, Mr Plumber and Mr Carpenter used them as well for various projects where failure was never an option.

    https://toggler.com/products/double-expansion-shie...

    a 1900 box is here, and it is stamped, not assembled and spot welded, it is stronger for this porpose, you must go down a bit to see it is a 4 Inch Squasre box.

    https://www.doityourself.com/forum/electrical-ac-d...


    Nice project though. And the last few years I worked we used them, for lighter duty, (say pipes on wall with not stress when pulling wire through said pipe), or smaller fixtures.

    Bravissimo Maestro

    0
    atesgoral
    atesgoral

    Reply 10 months ago

    A lot of great know-how here. Thank you! I might put these to practice in the second iteration of these anchors.

    I did this as a kind of a proof of concept to save the day, as well as opening up the implementation to public scrutiny on this medium to hear about great advice like yours.

    0
    Daveb1972
    Daveb1972

    10 months ago

    I strongly recommend NOT using tap cons for this project. The ones used have poor holding strength and being hardened the are far too brittle for this application.
    A better and more secure approach would be a toggle bolt all the way through, or large anchors with a forged and hardened eye. If the eye is long enough and the chain short enough it would be very unlikely to remove it by unthreading it.
    Tap cons break on installation more frequently than they would have anyone know. I use them to mount electrical boxes frequently.

    0
    lorenkinzel
    lorenkinzel

    Reply 10 months ago

    A toggle bolt is a poor application of hardware for almost any situation.
    Buy a decent bit instead of the one that comes with the tapcons & your breakage problem will go away.

    0
    atesgoral
    atesgoral

    Reply 10 months ago

    The stock Tapcon bits work well at the beginning, but burn out after 10-20 holes. Good advice on investing in a sturdier bit!

    0
    atesgoral
    atesgoral

    Reply 10 months ago

    Fair general warning! I've personally used Tapcons for long enough to learn (the hard way) how not to break them while driving them in: Drill straight, blow off the dust after drilling, and never ever force the screw if it seizes in the hole -- just remove the screw and correct the hole first.

    In my case, I have layers of brick, so a toggle bolt wouldn't be practical (unless we're thinking about different bolt types here).

    I steered away from a bolt with an eye because I didn't have the means to cut open the links to run them through the eye and weld them back or use a ring that I would have to weld. Using a padlock was suggested, but I wouldn't like that aesthetic. With the method I used, there's no need to close any loops with the chain.

    Great tip on keeping the eye small + chain short to prevent unthreading a threaded bolt!

    0
    mtbike2
    mtbike2

    10 months ago

    Constructive feedback here. Major weakness in this design is two things. 1) lock is only around lower tube. Assuming they get it off the wall they can just ride away. Instead lock it through the rear wheel to the vertical tube holding up seat then through your chain. IF they get it off the wall they cannot ride away. 2) EASY and silent way to get it off the wall. Stick a piece of wood or steel rod in the chain and twist. Keep twisting and it tightens up then pops the chain off the wall....silently. NOT sure how to fix that one though.

    GREAT instructive and nice measure to help prevent theft. After all any professional thief will get the bike. Just slow down the regular thief or make them look elsewhere. Strong work.

    0
    JohnR45
    JohnR45

    Reply 10 months ago

    You are right about the lock around lower tube: you may as well have one longer chain+ padlock at the other anchor, and do away with the bike lock at the home site

    0
    JohnH973
    JohnH973

    10 months ago

    You may regret putting the screws in so close to the edges of the bricks, because when the freezing weather gets to work, they may split away. Better to position the brackets in the centre of the bricks and space them off the wall with some washers if you need the chain links to be loose.

    0
    atesgoral
    atesgoral

    Reply 10 months ago

    Yeah, I had second thoughts about it. They're around 1/2" away from the edges. I normally hit the center of bricks when I'm mounting things. This time around, I wanted to center the link on the grout because of the thickness of the chain. I could have propped up the screws with some washers as you mentioned (and used a longer screw to account for the torque).

    0
    Loneman
    Loneman

    Reply 10 months ago

    I was about to reply with exactly the same comment, plus with them being so close to the edge a bolster chisel would have the brick cracked in seconds exposing the bolts and making them easy to remove.

    0
    BaznSuz
    BaznSuz

    10 months ago

    It's possible to purchase the sort of bolt that is used to secure steering locks on cars. The hex part of the bolt head shears off when the bolt reaches max tightness, leaving a rounded head, so that the bolt can only be removed by drilling it out - a noisy and time consuming process

    s-l1600.jpg
    0
    jliptrap
    jliptrap

    10 months ago

    Great idea! Have you thought of cutting the chain in half so you could wrap it through the wheels and then connect both ends with your lock?

    0
    atesgoral
    atesgoral

    Reply 10 months ago

    The locks we use are thick and heavy chains themselves, so I can only fit them by leaving the anchor chain as one big loop (if I correctly understood your suggestion of running the lock through the links).

    0
    sbelectrics
    sbelectrics

    10 months ago

    A nice security upgrade, compared to a gas pipe ! One possible improvement, used in at least one commercial security anchor, is to employ internal hexagon socket-head screws and tap a ball-bearing into the recess after installation. These are all-but-impossible to remove without a grinder.

    0
    atesgoral
    atesgoral

    Reply 10 months ago

    I've learned a new thing! I might actually go for that upgrade!

    0
    RachaelP38
    RachaelP38

    10 months ago

    Be sure to ask the building owner if you can drill holes into their property before doing so.

    0
    atesgoral
    atesgoral

    Reply 10 months ago

    Very important to get consent before touching anyone's wall! In my case I was lucky enough to be working on my own wall.