I have bought a set of the above limbs 36#@66" and am using them with a Hoyt Excel 23" riser. The first pair showed a reduction of 1 cm in brace height over 4 dozen arrows resulting in a marked inaccuracy which was disconcerting to say the least. I checked all the set up from tiller to limb bolts but could find no obvious problem. I assumed the string was a factor and changed it for a new one. Then a good used one. The result was exactly the same. I consulted the good people at Quick's in Waterlooville who also checked and changed the limbs free of charge. Happily I tried them out only to find exactly the same letdown over the same period. The string I use is D75/fastflight and this does not change in length.
I am certain that I have checked everything but cannot find what is happening. Once the bow has been unstrung, rested and restrung the brace height resumes its original setting, but again reduces as I shoot several ends.
Please can you help?