Fitting shown replaced original end fitting. We race under IRC; as such my question is if any one has experimented with reducing Spinnaker Pole length measurement and its impact on IRC rating.What problem are you trying to solve? This looks like a heavy lump of something unnecessary that adds to the swing weight of the boat.
Definitely not noticeable while sailingSince pole length is measured to the end of the pole, not to where the U-bolt is, the above fitting might result in a shorter measured sprit length if it is replacing the old fiberglass sprit cap that many 105s have. Where the U-bolt is fore-aft might be slightly less but likely not noticeable while sailing.