DIY: Bicycle Sprocket Mailbox Post

A DIY mailbox post made of bike parts is sure to be the envy of all the cyclists on your street.

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Hey, so this is my first guest post, but I am not sure it really counts since it was my husband that wrote it…and I told him he had to… 😀


A DIY mailbox post made of bike parts is sure to be the envy of all the cyclists on your street.

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This idea had been bouncing around in my head for a few years, but this week I finally had an urgent reason to build it – our mailbox post broke (again!), but this time I was unable to fix it.  We literally had the mailbox duct taped to the post for a few days while I had been working on this project, which was quite embarrassing.  Rather than planning this project out thoroughly ahead of time, I did most of the planning in my head standing in the hardware aisle of our local Lowes, but thankfully it came out alright. Learn from my mistakes 🙂 Also be sure to read the USPS guidelines regarding mailbox height and distance from the road when planning, especially if you have a grumpy mail carrier like we do.

A friend of mine owns a bike shop back in my hometown that specializes in BMX bikes, and for quite some time he had been saving me sprockets (or chainrings, depending on which end of the bicycling spectrum you may be familiar with) that would have otherwise ended up in the trash can.  While most bike shops do not deal with the volume of BMX bikes that his shop does, you can just as easily do this project with full-size chainrings or cassette cogs from road bikes or mountain bikes.  Ask around at local shops if they have any that they are throwing out from a repair/replacement, or if you have a very good relationship with a local shop ask if they can save some for you over the course of a few weeks.  Cassette cogs, in particular, can also be used for fun projects like a desk pen holder, drink coasters or clocks.
A DIY mailbox post made of bike parts is sure to be the envy of all the cyclists on your street.
Aside from the sprockets themselves, the only things we needed to buy were two square posts, a package of JB Weld , small 1″ angle brackets, a bag of concrete, and a mailbox mounting board. I highly recommend finding aluminum posts, as they will not rust, but steel posts can work if you prepare them to be in the ground – just don’t expect to get a very long life out of them!  All the other tools you may need are those commonly found in a garage or workshop, including a handheld file, sandpaper, a spray degreaser or Simple Green, a drill (or screwdriver if you are patient!), some type of saw or Dremel to cut the mounting board to size and cut the posts shorter if needed (I used a jigsaw myself), and a shovel or post digger.
A DIY mailbox post made of bike parts is sure to be the envy of all the cyclists on your street.
First, you want to prepare the sprockets and the posts for “welding,” ensuring the surfaces are flat and clean.  A file can help here, not only to make the surface flat but by scratching the surfaces with an edge of the file you can score the surface to help the JB Weld adhere better.  Sandpaper can also work if you don’t have a file, but it may take a lot more work.  I cannot stress enough you cannot skip the cleaning phase, as trying to use JB Weld on a greasy surface is about as strong a bond as gluing something to wax paper.
A DIY mailbox post made of bike parts is sure to be the envy of all the cyclists on your street.
When you are ready to start “welding,” be sure to mix the JB Weld according to the instructions on the back of the package, as a poor mix will not adhere well.  During the process, keep in mind the worst part about using the JB Weld is the curing time, which is 4-6 hours on average.  You need to make sure the sprocket is tight and flat against the posts for it to cure, so you can either set them on a workbench with heavy items or weights on top or use vise grips as a clamp to hold them tight.  Depending on your method you may only be able to attach a few sprockets at a time.
On our post, I also decided to attach the angle brackets with JB Weld, but if you have good quality drill bits you can instead drill small holes into your posts and secure them with screws.  These brackets are what will hold the mounting board to your post.
A DIY mailbox post made of bike parts is sure to be the envy of all the cyclists on your street.
Before installing the post into the ground, I highly recommend priming and painting.  This will ensure that the entirety of the post can be sealed away from moisture but will also prevent you from trying to spray paint on a windy day like I did!
When the post is ready for install, dig out your hole at least 12″ deep, although a few more inches won’t hurt.  Add the dry concrete mix and an appropriate amount of water to the hole (doing it this way is less messy than mixing in a bucket and pouring in the hole), install the post, and cover the top with dirt, making sure that the post is straight from all directions. I ended up using about 3/4 of a standard 80-pound bag.  When the concrete has cured – I’d wait at least one day – you are good to install and use your mailbox!
A DIY mailbox post made of bike parts is sure to be the envy of all the cyclists on your street.
Thank you, my husband, for sharing your hard work  (See?!? I didn’t take any of the credit).
Pretty cool, right?  Did I mention that he love bikes? He actually commutes to work by bicycle nearly every day…even in the rain or freezing cold. I, on the other hand, like to ride in my car with the seat warmers on. 😀
Do you have a cool bike-part project you would like to share?  How would you customize your mailbox post?
  • Reply Michelle November 24, 2016 at 12:42 pm

    Oh yes please, I love it Mr Dara 😉 I loved the way you shared the instructions and the photos. We learnt the hard way when we didn’t wait for our concrete to cure and our hole was also not deep enough 🙁 Your new bicycle sproket mailbox looks stunning. It’s all Steampunk-ishly, may it last a very long time

    • Reply darabre@gmail.com November 26, 2016 at 8:17 pm

      He did a great job explaining the steps. He just might need to guest post more often! 😀

      I hope it lasts awhile or else that mail carrier will be very upset with us! She already yelled at me once. EEEEK!

  • Reply Brittany Giles November 25, 2016 at 10:08 pm

    I really wish I was creative like this! I absolutely love it! You did an amazing job!

    • Reply darabre@gmail.com November 26, 2016 at 8:08 pm

      He did a really great job, it is the best mailbox in the neighborhood 🙂

  • Reply Jen November 30, 2016 at 10:29 am

    Crafty husband! This is so cute! We have a big community mailbox, but I wish we could do something like this!

    • Reply darabre@gmail.com November 30, 2016 at 6:55 pm

      He did a really great job, I guess I will keep him around 😉

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