As crossbow limbs get shorter, and we ask for more power, and speed it takes it's toll on the limbs, cables, strings, and all associated parts that impart that force into the arrow/bolt. Even with the reverse draw crossbows that allow for a greater power stroke have what I see as short limbs. Then we get into the flagship machines such as the Ravin "R" series crossbows. We are asking those short limbs, cables, strings, and cams to do a VERY serious amount of work. In the end we will need to replace parts sooner than later if we do alot of shooting. I have been pretty lucky with equipment, but I am also a realistic person. Looking at the designs, and what the machine/crossbow does--we are asking alot of the materials that make up the total package in the latest flagship crossbows. The consumer wants "more" out of their crossbow(s)--the manufacturers are trying to give us that--so--we got more power, more speed, and more wear on the parts that make up the crossbow.