ahhhhhhhhhh.....69, got it. This was attempted years ago as well....in fact, IIRC it was Cannondale that sold (for a little while at least) a 24" rear/26" front set-up. While this is pretty normal in the motor-cross world, it doesn't have the same effect on a mountain bike. Mountain bikes don't generally use rear tires that are significantly wider than the front for traction under power, etc... I don't care what power-tap you use...you don't produce 40 (or more) horsepower! Really though, wheels of different sizes have been quite commonplace on bikes pretty much since they were invented.

Now, that being said...the idea of it is one thing that I do LOVE about mountain biking vs. road riding. Mountain bikers (gross generalization) tend to be more experimental with equipment and set-ups, always looking for something new, something different than what the others are doing. I remember years ago when I was "in the biz" I would see some crazy stuff being tried out. But even if it didn't work, it was worth it, because at the very least, something was learned, and development happened, and it still does. Good stuff my friends.




EDIT: What reflectors? Good looking Salsa!