In industrial production, bicycle frames are usually made of aluminum. The advantages of carbon frames are low weight and possibility of creating different aerodynamic shapes, according to your wishes and requirements. If you love biking and customized bikes, building a carbon bike frame is the next big step for you.
Make a square wooden frame out of the wooden box using an old bike frame to determine the size. Cut the boards with a hand saw and connect them with large screws.
Pick a bike frame shape. The triangle shape is the most common.
Set the metal pieces of your bike into the wooden frame (bracket shell, head tube, seat tube, cable stops and rear dropouts) and lock them into the final position using pieces of wood and screws. The position of metal pieces must follow the outline of your new frame.
Create the core foam. Make rods from polystyrene with a hot wire foam cutter or a knife. Put the rods into the wooden frame and snap them into place. Glue the rods onto the metal pieces with epoxy. All the rods and metal pieces have to be perfectly aligned.
Sand the rods, especially in the connection areas. Put on safety glasses and a dust mask to prevent danger from small airborne particles.
Laminate the foam core (you need about 200 grams of woven carbon cloth per square meter, epoxy resin and hardener). Wet the pieces of carbon with water and wrap them around the foam core in equally sized layers.
Wrap each layer of carbon with perforated electrical tape to assure compaction during drying. Drying of one layer takes approximately five hours.
Remove the electrical tape after drying and add another layer of carbon. Repeat the process at least 10 times. Leave the bike frame in the wooden box and let it dry. The drying time can last up to 48 hours, depending on the room temperature.
Polish the surface of the frame. Sand it or spray it with a clear varnish.
Always wear a dust mask when sanding polystyrene and carbon. Wash all your clothes after sending the carbon and ventilate the room you have worked in. Don't touch the bike frame while you are working with a foam cutter.