Introduction: Cheap and Waterproof Smartphone Holder for Bikes

The goal of this little and easy project is to make a cheap, affordable and waterproof smartphone holder for my mtb. I just wanted to use my smartphone when riding my bike in order to use Runtastic-like apps without buying an expensive bike computer. Actually, I spent 0 € for this holder, since I was able to find all I needed in my garage, using spare parts or scrap.

Step 1: Gathering All the Materials and Tools

Basically this holder is a transparent pocket in which your smartphone lies on a foam pillow for shock absorption purposes. So the materials needed are:

- plexiglas sheet (or any kind of rigid material sheet, like plywood)

- ski strap

- foam

- steel wire

- duct tape

- glue

The tools I used are:

- angle grinder

- scissors

- measuring tape

- sandpaper

- marker

- wire cutters

Step 2: Making the Holder

I started taking measurements of my smartphone and I decided to cut a 8 x 14 cm square from the plexiglas sheet with an angle grinder, since it's the only tool I have capable to cut this material. Also, we need two parallel cuts in order to make the ski strap to pass through and fasten around the handlebar. The size and distance between them depend on your handlebar and width of your ski strap. Then I cut a piece of foam of the same size of this plexiglas piece and glued onto it. I covered this foam with white plastic from a plastic bag, in order to squeeze the foam a little on the edges and to make the phone sliding in and out more easily. I simply used transparent duct tape on the back. The same with the transparent plastic, leaving a longer extremity on the top. Now I attached some strong tape on the top with a piece of steel wire on top, in the middle of two layers of tape. This feature allows the transparent plastic to fold on the back and wrap firmly around the long edges, avoiding squirts of water or mud to hit your precious phone.

Now your holder is ready to go!