If you have a 28" draw length on a compound, you will probably loose 1 to 1 1/2 inches of draw length on a traditioanl bow. Check to see the exact draw length. If it drops 1 inch you will loose 2 pounds of draw weight.

You can still shoot carbons but, like Alpha said, they must be spined correctly. If not, you will have very poor arrow flight. Also, make sure to tune the bows brace height and string nock with properly spined arrows.

45#'s is a good starting weight to learn proper shooting form. It may take a while to become proficiant but keep at it.