Who said that wooden bike is impossible to make one? A Chinese villager has proven that statement 100% wrong by making his totally-wood-even-the-frame bicycle. Check out the follow picture where he brings the bike for a spin around the village:
It practically no other material except wood art. The creator, Peijia Wu is a local carpenter (artist?) in that village and he is brilliant enough to create something that people thing is impossible to make. Even the joints were fixed with wooden bungs. No Screws or anything else.
You may also find the chain is not existed in this bike and Peijia Wu replace the chain with a traditional rod-crank system. The “look & feel” is certainly not so good, but it’s absolutely a state of art. However, I believe this bicycle only capable of handling smooth ground. Rough ground will probably hurt your bottom (because there is no proper cushioned seat), and it might break the wheel frame.