The Amazing Grocery-Getter Box for Bikes

In this howto I'll show you how to build the perfect grocery-go-getter box for the rack on your bike. Bike racks are usually $20-60, and are very handy, but they don't keep your coat or bags or anything else you are carrying, from falling off the side and into the wheel. This homemade box is not only extremely lightweight, it is durable, quite cheap, and is a good way to recycle all those old political sign boards.

This box is the perfect size for a coat when you're not wearing it, or a grocery bag with 10lb of potatoes, snacks and almost anything that fits in one grocery bag, from your local grocers.

To build each one of these you will need:

• A sturdy plastic signboard - standard 2x1.5ft size.
• Four beefy 1-2 inch long bolts with nuts and washers to attach to bike rack. You must have a drill bit the same size or slightly smaller than the bolt.
• Paint stirrer or other small wooden piece to attach to secure to rack below.
• Four small nut+bolt combinations, about half inch long. The 0.5 inch machine screws with matching nuts pictured were just the right size to bind two layers of plastic wall for the front and back. (about $5 per box of 100, from the local hardware store).

You will need no special tools other than a drill,a box cutter and a measuring device and perhaps a hacksaw if some bolts are a little too long.

Place your corrugated plastic near the rack and measure approximate size - you will want several inches at least for the walls, I used 5.25 inches which makes a perfect size for a standard grocery bag. Measure and mark a square 5.25x5.25in at each edge and extend the line. You'll have something like the attached photo - it is easier to mark on signboards like this with less writing and colors.

When you cut, make sure you don't cut through what will eventually be the end piece reinforcements. You will only need to cut through on the red lines noted in the picture, and you will need to barely cut through part of the plastic on the neon green lines in the picture. Try the box cutter's lowest setting and cut just until you can make it fold.

Measure and drill an appropriately sized hole in both the wooden bottom piece, and the bottom of what will be your box. These must be appropriately spaced for your bike's rack, probably a few inches from the edges.

You will also want to trim the end pieces where the plastic on the end overlaps, so you have simply two layers on each end. Drill through and fasten with a nut and bolt. If too long, take the bolt out and cut it to the right size with a hacksaw and vise.

With the four end flaps fastened and the bolts pressing the piece of wood and the box together to the rack, you have a handy grocery bag carrier that is great for carrying odds and ends too! Use a bungee cord around the whole box to keep items from bouncing out.

Tip: Check the bolt ends below the rack from time to time as they may start to loosen... maybe it's just mine, I had just hand tightened these to make the box easy to take on and off.

You should now be all good for preventing your stuff falling off the sides or slipping off the back of your bike, but what if you want a mug and a walkie talkie / amateur radio handy, but not bouncing around or bouncing out?

If your radio comes off when you clip it on to the side and go over a bump, make a slit matching the belt clip end as pictured, to keep it on the side of the box until you unclip it.

To keep your mug upright, first cut one or more large rubber bands in half. Then drill a small hole maybe 1.5 inches from the corner, where you want to bind the mug to the box. Press the ends of the rubber band into the hole from the inside by pushing each end in with a small nail. Pull tight and knot the end outside the box to fasten. Place your mug in the box as pictured to keep it from falling over.