Shaft spine alignment

Poss a question Sanders may know the answer to as its his field. I have been looking on you tube about shaft spine alignment and its a new one on me. If there is such a thing ( and it seems there is ) surely all shafts should be fitted correctly. What are the consiquenses of a shaft being fitted at 90 degrees out? Also what noticable benifits could be seen by having your shaft refitted correctly?

Cheers Dave CAC handed Geordie. 

David

the spine is the theoretical line along the length of the shaft at which it is stiffest.  On a steel shaft this will usually be along the line of the weld in the original stock tube.  The metal around this area is slightly more brittle and thus less flexible meaning that the whip of the shaft is different depending on how the spine is aligned to the head.  Certain other factors can also affect the flex, such as the ovality of the tube, material grain density and thickness.  In composite shafts the accuracy of the weave lay-up and binder thickness have much the same affect.

Spining a shaft (you can try this if you've got a spare shaft - no head or grip) is basically gripping the shaft at the thick and and twanging the other.  The shaft will start to flex and it's then pretty easy to identify in which plane the shaft natural describes an up and down movement as opposed to a figure of eight.  Thus fitting a shaft with the spine facing the direction of the ball flight will result in it being slightly stiffer than if its at right angles to it.  It's a bit like trying to bend a plastic rule along it's length, it's a lot easier to bend it flat down than across the flat.

So that's the theory, whether or not it makes much of a difference to us mere mortals is debatable.

Something interesting to consider is how many people actually play a shot "down the line"? What I mean is most people tend to play with a draw/fade/hook/slice for a shot (whether deliberate or unintentional) and that will usually mean swinging from in to out or out to in - very few I would think tend to play exactly square. Often one (attempts) to manufacture a shot by opening or closing a club face. These things obviously change where the spine is in relation to the "line" too, so is it going to make a big difference where the spine is.....one would hope not, but then it may do. Once you really get in to reading a bout Spine alignment you start to find it's often a very personal issue with many theories for different results.

Just to throw another little taster in, the spine will change with the torque reaction of the head.  But not linearly....

Just thought I'd mention that.