Callaway make this shaft flex, it is designed in between a regular flex and stiff flex shaft.
A regular shaft has regular flex.
You can replace that shaft with any on the market. Since that shaft came with the Ping ISI Irons and had a firm flex, since the W44 were regular, you should get a stiff shaft put in for a replacement.
Hi....I have played Ping clubs for serveral years..and yes the Ping soft regular shaft is equivilant to the senior shaft or A flex of many shaft designations.
Stiff flex is simply a stiff graphite shaft. The flex of the shaft is basically how whippy it is, stiff has a little whip in it, but less than a regular. 60 would be the weight of the shaft, 60 grams.
Shaft flex is determined by the vibration frequency-- this is measured by fixing the shaft's butt and attaching a 10-ounce weight on its tip and then vibrate it to its vertical direction.
A senior flex shaft is a very flexible lightweight golf shaft which is ideal for senior golfers. They usually have a low kick point which is ideal to get the ball in the air with the slower swing speeds of a senior golfer.
Remove the inspection plate/dust cover from the bell housing. Disconnect the torque converter from the flex plate. Remove the drive shaft from the transmission. Separate the engine and transmission and support the transmission while you remove the flex plate. Replace the flex plate and put it all back together.
A stiff flex is the flex of the shaft usually for swing speeds between 90 and 105 mph.
A wise man's guess would be Stiff Regular flex, between Stiff flex and Regular flex.
There is actually very little difference between senior and ladies flex shafts. You will find that the senior flex shaft is slightly heavier. They are both aimed at golfers with slower swing speeds, to help them get the ball the air easier.
A Golf shaft which is too stiff will cause a slice. This is because the shaft is too stiff for you to square the club face at impact. You can get custom fit to see which flex is best for you, as a shaft which is not fitted correctly can affect your game.