Alright, I started making a hackjob bass and I was working on shaping the neck and such today and I realized that it was wider than my 4-string neck and maybe I can make it into a 5-string.
The neck is 4.8cm wide at the thinnest part (by the head), which is approximately 1.88 inches.
I was wondering if this is fully plausible (I have never owned a 5 string before and thus cannot measure one myself). I am perfectly fine with a narrow necked 5-string. That may even be preferable.
A picture of it: http://s2.postimg.org/ljsh3hpmv/DSC_0308.jpg
Couldn't find a metric measure, sorry. :P tl;dr what is ideal 5-string neck thickness at the head, and what is the narrowest 5-string neck in same place.
Any ways thanks for the help.