Best Type & Length Truss-Rod for a 25.5" Scale, 24 Fret Bolt-On Neck ?

[jtm45]

I just wanted to be sure about which length and type of Truss-Rod is best to use in a bolt-on modern style (Superstrat/Blackmachine) neck with a 25.5" scale length and 24 frets ?
I'm looking at them now and they have them in 440mm, 445mm and 460mm length versions. I'm assuming the longest i can fit in the neck the better, which would be the 460mm, but would the length interfere with threaded inserts in the neck heel if i fit them in a AANJ/Blackmachine type of neck screw layout ?
I want to use the rod & flat bar style with the allen-key adjustment that will allow me add a forward or backward bow but there seems to be two different types.
The same seller is selling some as 'Double' type and others as 'Dual' type and they make the point that one is different to the other.

Can someone please explain the difference between these two and also let me know which one it is that i want.

This is the one they are calling the 'Dual' type;



And this is what they're calling the 'Double' type;



I had it worked out that to do what i wanted it was the first one, the 'Dual' type that i needed but seeing that there's this other kind, the 'Double' type has got me second guessing myself.

Any help would be greatly appreciated. The last thing i want is to find out after finishing my neck that i've fitted the wrong type of truss-rod!

 

[ahvia_musicom]

1st pick is dual action, 2nd one is single action dual rod as supposed to fender single action single rod, i hope i made sense, i buy 18in rod for 24 frets and 16.75in-17in for vintage type 21-22 fret necks, if they dont have them in stock i order the longest and cut it to size then weld it again

 

[jtm45]

Thanks for the reply!
I think i understand what you're saying but i'm still not 100% certain.

 

[foreright]

I have bought truss rods from this eBay seller previously. I did ask him this exact question directly and you want the "dual" rod and NOT the "double". The dual rod allows you to bow the neck in both directions.

HTH

 

[Pikka Bird]

Yeah, if you want to be able to adjust the neck forwards then the first is the one for you. With this type the entire rod rotates, and is threaded at both ends. It has a reverse thread cut into one end (apparently the end that's shown in the picture) that enables it to tighten in the "push" direction too, inducing forwards bow.

 

[jtm45]

Thanks guys!

That's exactly what i needed to clarify in my mind. I wasn't sure exactly how the dual type worked and you've answered that for me nicely Pikka Bird.