Cramping Playing Thinner (J) Type Necks

[Mastermold]

This is very true however in my case I dont know that this is the problem. I have never experienced this problem with any of my other basses including my Upright. It just seems like having a super thin neck puts my hand at an uncomfortable angle. Again, It has never happened with other Jazz necks, just the Geddy which is about as thin as they come.

In my case it's just sometimes when playing a lot in the first position (a long tune in F for example) I would experience any issue but otherwise I've been able to jam on a Jazz neck as well as I can on a Precision.