NL25 - JJ basic bet-sizing Q

[Everlong]

This is a very basic but kinda ipmortant part - how much to bet with an overpair on a relatively safe flop. Skip if you think this is kindergarten stuff.

Table is full of cold-calling passives. I guess they are setmining or playing ATS.

I used to always bet full pot here but I am starting to think it is not optimal and am leaning towards 3/4 nowadays - since we are obviously not eager to felt and will probably have to fold to very strong resistance.

Enlighten me.

PokerStars No-Limit Hold'em, $0.25 BB (6 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: 2+2 Forums)

Button ($42.30)
SB ($29.40)
BB ($15.95)
Hero ($26.25)
MP ($30.15)
CO ($26.75)

Preflop: Hero is UTG with J[img]/images/graemlins/club.gif[/img], J[img]/images/graemlins/spade.gif[/img].
<font color="#CC3333">Hero raises to $1</font>, MP calls $1, CO calls $1, <font color="#666666">1 fold</font>, SB calls $0.90, <font color="#666666">1 fold</font>.

Flop: ($4.25) 3[img]/images/graemlins/spade.gif[/img], 6[img]/images/graemlins/club.gif[/img], 9[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(4 players)</font>
SB checks, <font color="#CC3333">Hero bets ?</font>