How do these possibly hold up? Even if the wood was solid it's still not very thick considering the force things like the rim, seat/chain stay, head tube, and top tube need to support. While they're beautiful to look at I'd be terrified I'd snap the bike in half while climbing
Nice looking bikes, but practically speaking, why not go with bamboo? Comes hollow, and very strong for it's weight. Also very fast growing compared to the trees mentioned. I'm taking a relatively inexpensive steel bike, chopping out a good portion of the frame tubes and replacing them with a bamboo/carbon fiber composite. To give an example of the weight difference, the fattest steel tube piece I cut out weighs 1lb and 7 ounces. The replacing piece, bamboo wrapped in carbon fiber is longer and weighs 7.7 oz--almost a third of the weight. Weight is not the primary concern though, but rather the vibration dampening. The bike will eventually have a small motor on it for pedal assist and I want to be able to do very long rides at greater comfort.
lilzaack make them... They'd probably cost exponentially more than a metal wheel set because the difference in time and materials to make them. I highly doubt they're every day bike kind of wheels though as I can very much see the spoke nipple ripping straight through the wood if your wheel gets out of true.