they say not to string em backwards. i remember doing this with my red fiberglass kids bow i had , and it made it almost sort of reflex. i threw it out a while later when i realized i had made it splinter...
i have been reading up on sinew , and if you use sinew it will pull your bow a bit backwards , and you can/will gain weight depending how much and how you apply it. it would also give you some assurance as a backing...
i take it you came in under weight?