some truss rod help

[warwickben]

so iam makeing a seven string bass. the neck is made of 7 parts weng and purple heart. do i need to have two truss rods. i was told that if i didnt the neck would have major problems. if i do need to have two should i have them angled out , ie following the taper of the fret board. or should they follow the center line of the neck. also could i use 2 spoke style truss rods and the end of the neck, not at the head stock. i swear ive seen neck thru basses like that. but i was told it wount work.

 

[Suburban]

I don't think you'll run into any major problem, twist and such.
However, a very stiff neck is hard to move at all, and 7 strings will make it hard to straighten without a jig.

If you settle for 2, I recommend to follow the taper of the neck. This will counteract any tendency to twist, and make it possible to vary the relief slightly between bass and treble.

Spoke wheels work well, even very well! The groove must be correctly done, which adds some work with taper layout.

 

[Dirk Diggler]

I've only done 6 strings but only 1 works fine with Wenge and Purple Heart. The neck on my first has only ever needed adjustment 1 time in over a year. Those materials make for a very, let me stress, very solid neck. That's why my first paying customer wanted the same neck for his build. And I can't believe that extra string will make that much difference. YMMV, but my Warrguitar 8 string only has 1 trussrod and it's only maple and a few walnut stringers and it's never had an issue.
Good Luck,
Dirk

 

[warwickben]

thanks for ur guys help. when i get the bass done ill post pics.