Need to curb bucking?

Is there anything in your rides that have been different at all--new bit, bridle? How about his feed anything different with anything there? Horses don't hate that I am aware of, they do things out of fear and out of habit. They are a prey animal so if they fear something their instict is to get out of there as quickly as possible. You probably know all of that. If you have exhausted any solid reason for him acting this way, I would say it is a learned reaction to something. A horse will give signs before they bolt or buck, pay close attention to these signals and head them off before he can do it, make him move his feet, small circles keeping your outside leg into him. My trick is to reach my hand down the rein, pull it back until it about reaches the waistband of my jeans, pulling his head right around--if a horse can't get his head down and get his nose out, he can't jump, buck or bolt. You will feel when he gives in to this, the second he gives, let go of him and let him rest and think about it for a minute. Resting is a reward for any horse--they are pretty lazy creatures. Be consistant and hopefully you will see his bad habit subside. Good luck!!