Draw Length

[Marcus26]

Point weight doesn't change arrow spine.
Spine is a static figure that is the amount of flex induced to the arrow using a set amount of weight. Changing the arrow point weight won't change spine. The only way to adjust spine using the point is to change the insert length of the point which moves the front node.
Anyone who uses the words 'dynamic spine' needs to be shot because it doesn't exist.
Changing point weight will change the amplitude of the arrow flexing, but not teh frequency, and it's the frequency that matters.

Changing poundage won't change draw length because draw length is determined by cam rollover which is set independently to the limb positions.
Changing the draw length by altering the starting position of the cams will alter the bow's poundage.
Changing draw length by changing the draw stop position will not alter poundage.

[geoffretired]

A strightforward question about draw length and increasing bow weight has turned into some pretty technical stuff about spine. Not for the first time, a basic question brought out some very interesting responses. I find myself on a steep learning curve in these situations. I've never considered the ,frequency of the vibration, as the one that matters. For a recurve it is important( now that I come to think of it) otherwise the arrow would be bending the wrong way when it passes the riser. With a compound, the bends are vertical so clearing the riser isn't an issue. Is it necessary to have the right frequency, for the fletchings to clear the rest? I can't think of any other reason, but I am happy to learn more. Frequency, if I remember my science lessons, is determined by the nature of the material and its length, perhaps this is where the differences between aluminium and carbon start to have their greatst effect.
The amplitude of the vibration, which can be changed with weight in different places, must have some bearing on the flight of the arrow, or am I wrong? If there is too much bend, much energy will be wasted as the airflow will be more disturbed than with minimal bend. Also energy put into bending the arrow cannot be recovered, so efficiency is lost.
I am curious to know the truth; I don't like mysteries.