5 string truss rod adjustment
 

I've been checking out the John Carruthers bass setup video series on youtube, and he gives the measurement of .381mm at the seventh fret as sort of a rule of thumb measurement for the truss rod on a four string bass. If this is the case, what would a good rule of thumb measurement be for a five string bass?



http://www.youtube.com/watch?v=te44eWXd9pc

I personally prefer 0.382 mm ;)

Seriously, I use the same procedure for 4s & 5s; fret down on 1st & last frets then measure gap between deepest string (E or B), & adjust truss rod for a business card's gap between string bottom & 8th fret's top.

Sounds funny, "rule of thumb", specified down to the nearest micron.

Anyway, that's .015", and I use between .010" and .015" for a 4 string.
A business card is .010" to .012".

If the 5th string is high, as in 'C' above 'G', not high action, a 4 string relief value should work just fine.

If the 5th string is low, as in 'B' below 'E', I would start with a 4 string relief value and only add more relief
if the lowest string absolutely needed it. I wouldn't compomise the other 4 strings unless I had to. For example,
if some extra action height didn't work for the low 5th string, then I would add a little more relief.