55g x stiff vs 60g stiff, whats the difference?

[irishlad88]

Iv been using a 60g Aldila RIP stiff shaft on my Titleist 910 driver and works just fine for me. I went to a club fitter and using flightscope they could only get me 10 extra yards on my own driver using a Fujikura 55g F1 Motore x stiff shaft. What is the difference, the x stiff is 5g lighter than my stiff shaft so why would an x stiff be better suited? (I ordered a Taylormade RBZ in the Fujikura since that shaft gives me 10 yards and the RBZ is also longer than the 910)

[Mr. Desmond]

Shaft flex is measured differently by all manufacturers. There is no uniformity. Torque might also be different and it is measured differently. The construction of the shaft and kick points may also be different.

Nothing is simple. That's why you go on the LM.