changing flats on a bass with no truss rod

[mr sprocket]

I have a 5 string Dean Pace bass. It is basically a 35" fretless neck on a stick but that stick is pretty big to emulate the feel of an upright neck. There is no truss rod on the bass.

I am getting ready to change strings. The flats on there no are having a hard time holding tune. I am not sure what they are although I suspect by the red silks at top an bottom they might be GHS.

I am considering the TI flats but I am concerned they will not put enough tension on the neck which may require work to play properly.

Should I worry about that or try another string? I could try Chromes or even some tapewounds.

[GianGian]

I would check tension charts before doing anything. You could try something a bit tighter, like the Steve Harris flats or something like that.

[mr sprocket]

I don't think the roto flats come in a 5 string extra long set. The roto tapewounds do though. It might be easier to try the Chromes.