Now I know you can add sinew or wood to a wooden bows, but can you add draw weight to a fiberglass bow?
I talking about maybe 5 more pounds or so?
If its a recurve you could staticate the tips by gluing on an overlay to the belly...that adds some weight. If its a longbow you might be able to add some power lams to the belly and that would do it as well. Either option would change your tiller and the way it shoots, but it will add weight.
The only real easy way would be to shorten it. Jim