So, on my longer rides, ~30 miles or more, I get really sore and stiff in my neck. Actually, more specifically, it's the prominent vertebrae (thoracic - C7?) just below the neck that gets stiff/sore and lasts for 2-3 days.

I've been riding for just under two months and am wondering if this is this something that will get better with time or do I need a bike adjustment?