.009s (the smaller the gauge, the easier to bend) you can get .008s in some brands but i wouldnt bother
note to threadstarter, the smaller the gauge, the more tinny and less strong the tone's gonna sound. But go for 9's if u really truly need to bend lol, cuz any thinner and u'll be popping strings here and there if u attack the strings heavy. Personally, i bend decently w/ 10s and i have 11s on my artcore :shrugs:
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i use .11s and have no problem with bending, however ive been using .11s for years so im used to it, and i yune a half step down, but to me anything thinner sounds like crap.
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it depends on how strong your fingers are. if your using a thick gauge and got used to bends with them and move down to something lower then you find them real easy to bend but if you got used to bending on thinner strings then moved up a couple of gauges you will find them absolute a bitch to bend but you grow into them