D
It depends on what you mean by "lighter". I generally use 45-105 with roundwounds but that's to stiff for me with most flats. I normally end up around 40-100 with flats, although in some cases I can go lighter. TI Jazz Flats is one example. They're really a bit on the floppy side for my playing style (especially the A-string) but I'm willing to adjust my playing for the wonderful, unique tone they deliver.
There's ONE type of flats where I'll just suck it up and go 45-105 and that's Roto 77s. The lighter sets just don't give the me same tone and they're still rather stiff. So I might as well use 45-105. At least they're stiff enough to set the action lower than any other strings I can think of. Which mean that after a proper setup they're really not that hard on my hands after all.
But generally it's 45-105 with roundwounds and 40-100(ish) with flats for me.
There's ONE type of flats where I'll just suck it up and go 45-105 and that's Roto 77s. The lighter sets just don't give the me same tone and they're still rather stiff. So I might as well use 45-105. At least they're stiff enough to set the action lower than any other strings I can think of. Which mean that after a proper setup they're really not that hard on my hands after all.
But generally it's 45-105 with roundwounds and 40-100(ish) with flats for me.
-canned as soon as the function check was done - was a set of old, salvaged Chromes that I put on a '15 Tom Hamilton G&L ASAT Bass - because I had no other flats to put on it at that time. They were probably 45-105s; They were - OK, on that bass; until they died, about a year later. And were replaced with a set of Fender 9050L's (45-100) which have been my default flats for longer than I care to think about... 