You need to set the bead on the rim. I can tell you the ******* method lol.
-Take the tire & rim off the bike
-Spray a small amount flammable aerosol in the tire (Like brake clean, carb clean, hair spray etc.)
-Throw a match and... LOOK OUT!
The force of air exploding out inside the tire sets the bead. It's ghetto I know but it works i've used this a couple times, it does work. Just be careful not to spray too much and catch the tire on fire.