It has been done before, and successfully. Naturally you will end up with a shorter bow, but you will also end up with a heavier draw weight, unless you really tiller it down and knock some weight off. I would be careful not to shorten it up too much becaus then you will put stresse on the bow that was not intended by the design, although I don't see where it would be any worse than a guy with a 32" draw length drawing a bow that is rated at 28". I don't know about the Black Bear, but many of the Bear bows used to be advertised as "draw length - unlimited"
For safety, once you have the new notches cut, I would add an overlay on the tips, possibly using the material you cut off.
Go for it. Watcha got to loose.
JUST MY THOUGHTS