Relationship between string gauges and action

[steamthief]

I replaced the worn-in set of 45-105 Fender 7150s on my Jazz bass with a brand new set of 50-105 Slinkys, and the action has gone up 1/32" higher.

Is it a safe bet that going up or down a gauge will heighten or lower action by 1/32"?

[therex]

its because of strings tension
the thicker = the more tension to the neck so minor adjustments are needed

[XylemBassGuitar]

Generally, yes it is a safe bet that changing string gauges will alter your action.

Like therex points out, all things being equal thicker strings will be under more tension. The extra tension will cause your bass' neck to upbow a bit more, which can cause an increase in action.

Many basses will benefit from a basic setup after you change string gauges. The truss rod, action, intonation and sometimes pickup heights may need to be adjusted.

If you understand how truss rods work and are comfortable adjusting them, I would tighten your truss rod just a little bit, to counteract the added tension from your new strings. I would also check and re-set your intonation if necessary.