How To Evolve Golbat into Crobat?

Answer 1

Crobat doesn't evolve by leveling, but by friendship. This is basically how much your Pokemon trusts you. You can increase friendship by simply having it in your party and walking around with it, not letting status problems linger and preventing it from fainting. This may take patience however. There are ways to speed up the process of gaining friendship, but that would depend of what game you're playing. (Like visiting the massage lady once a day in Veilstone City from Pokemon Diamond/Pearl)

Answer 2

well i played ruby and when my golbat got to level 83 it evolved so that's the way of hard work (and rare candies)

Answer 3

all you have to do is to make Golbat's friendship high enough for Golbat could evolve into Crobat.