Carbon fibre neck rods

[scojack]

Cheers Pete , it's already done ...i'm taking a punt and going without.
IanM

[Beer of the Bass]

This thread is a couple of months old, but I've just picked up a carbon fibre rod from a luthiery supplier that I'm going to use in a mandolin neck, and it seems noticeably different from the material I used in my five-string bass neck. The rods I used in the bass neck were 6mm square from a model aircraft supplier in the UK, and the rod I've just picked up is 1/4" by 3/8" from Luthiers Mercantile International. While the different size makes the stiffness difficult to compare, the LMI material feels a lot stiffer and I can barely flex it at all, even across the 1/4" dimension and it rings with a high pitched chime like a piece of ceramic when knocked. The stuff from the model aircraft supplier has some spring to it, though it is still stiffer than a 6mm square rod of most hardwoods. I presume that different grades are available for different purposes.
So it would appear that not all carbon fibre rods are the same stuff, and it may be that if maximum stiffness is the goal it could be worth paying the extra from luthiery suppliers. Although the bass neck is doing fine after 18 months of medium gauge flatwounds, so using the more flexible material doesn't seem to have been catastrophic.