To stretch your hip, squat down with one leg's ankle sitting across the other leg's knee. Hope that made sense -- you do one side & then the other. Squat down into it as much as possible and hold for 30 seconds.
Cramping could be a lack of potassium or magnesium. Make sure you're taking vitamins. Also make sure you're doing plenty of stretching after riding and after lifting weights. Drink plenty of water also.
I wish I could help you more -- as you know, I've had my own stiff neck issues.![]()