so the idea for a snowmobile bike had been kicking around in my head for awhile. I wanted to utilize skis somehow. Then it hit me how to do it and I dumpstered an old Murray BMX frame and got a pair of skis my roommate dumpstered and I went to work on it!

Here she is in all her glory. This was a BMX and I threw on a dumpstered MTB fork and cut in half a ski. Then I went to the hardware store and got some clamps with a shape like so _/-\_, basically an arch. I then took a front hub off a kids bike and bolted in to the fork, bolting the two clamps to the ski.
The ski has an up and down pivot motion and I have been able to easily ride down my driveway, into the street, and up the curb into the neighbors yard. On sunday I even rode it around the frozen creek across the street. This thing is SOOOOOO much fun and it actually gets going pretty fast with minimal effort (just watch those dry spots). I also put sheet metal screws in the rear tire for added traction.
Only improvment I want to make is a set of teeeeeeny cranks to improve clearance from the ground/snow. I've just been to excited at the prospect of riding this to get to that.
Oh and yes, I plan on taking this down a hill and breaking an arm.
Heres some more pics: