Not all foam cores or composite cores are equal. Some are made with polyurethane resins and the stronger materials made with the more expensive Epoxy resins. The density and strength of the material is based on the percentage of filler to resin and the characteristics of the material is based on what filler bulks out the resin system, stronger weaker lighter heavier more dimensionally stable less dimensionally stable. The elasticity of the core is meaningless. Lets assume that the composite core is half as elastic strong as bamboo. Okay then here is an example just and example and not and actual situation just and approximation, then assuming the bamboo core alone without the composite bow facings generates a bow drawweight of 1Llbs and the composite core .75lbs and the bow weight is 55lbs So the bamboo core is responsible for 1.8% of the drawweight and the Composite core is responsible for 1.3% so the difference in bow weight generated is 0.5%. 0.5% is nothing and would hardly affect the speed at all. However a 20% weight reduction in core mass is about a 7% mass reduction in the whole limb and that is significant and represents about 2 fps. But some composite cores will be roughly the same weight as the wood core and so no different.
Reply To: Widow test drivejpc2017-01-15T18:12:43-07:00