I bike a fair amount and have had sharp, shock-like neck pains for a few seconds in the past few days, what could these be?

Pinched nerve. You could have a pinched nerve in your neck from poor posture while you're biking. You should have the height of your seat and handlebars checked, to make sure you are in a good posture.
Facet joints. When you ride a bike your neck is in extension. This places increased force on the neck joints (also known as facets). This can irritate the medial branch nerves of the joint which will trigger a "shock-like" pain in the neck and/or back of head.