"bicycle" and "vinyl" are two words that always trip me up when spelling because it FEELS to me that the y should be the longer vowel of the two.
by + icicle = bycicle
vy + nil = vynil
I always have to remind my self that's bi- as in 2, then cycle even though it's pronounced cicle. And for "vinyl", well, I just tell myself that's the "other way around".