In April of 2012 I decided to build a plywood bicycle, to distract myself from my physics homework.
The bike had three gears, two with 28 teeth (one of which takes the place of the chain) and one with 21, producing four revolutions of the wheel for every three of the crankshaft, this gives the bike a max speed of about six miles per hour. The gears didn’t last long; I replaced them seven times after an average of two miles.
The wood bike is modeled after my mountain bike; I cut out cardboard templates of all the pieces I would need and traced them on the plywood before cutting them out.
I constructed the bike from a single sheet of 23/32 plywood, about 14 inchs of 2×4, 58 screws, four roller blade wheel bearings, two 5/16 bolts, one 1/2″ bolt, some 1/2″ dowel for roller bearings and some glue. I made all the cuts with a jigsaw (I did not have a bandsaw at the time).
Here’s the link to the news story that 11Alive (our local news) did: http://decatur.11alive.com/news/news/144833-bored-teen-makes-wooden-bike