Horse bucks

My horse Rebel is a smooth ride and a good ride. The only time I have had a problem is when you kick him to gallop or run. Trail riding or slow riding he is awsome. When we are standing and you kick he is fine. I am learning so if I am wrong let me know. I think it is he is not expecting the kick and it spooks him.

What do I need to work on with him?

Hard to say without seeing it.
Does he only buck when you kick? Perhaps you are being too strong and abrupt with your cues. You should be suggesting what you want him to do first, not jumping strait to demanding. Give him a chance to decide and then apply more pressure as necessary.
Smooching works also as encouragement as well as pressure from being (whip of sorts)
For example, spurs are meant to make a rider's leg cues clearer when asking to yield the body or heighten the stride. Whips are meant to increase a horse's speed (reasons why bronc riders wear spurs & not whips and jockeys use whips and not spurs). Sometimes too much pressure in the leg area when the horse is in motion like that can cause them to bring their bodies up in a buck.
Many horses are dull to this though or have learned it means otherwise.
The hard part is determining exactly why your horse is bucking. First you must rule out pain or unconfidence issues. Then determine whether it is lack of understanding on his part or unruliness.

Yes that is the only time I have had him buck is when I kick. He doesn't buck every time I kick. The first time it happened was at a play day kicking him to pick up speed on the game. When I walked the game he didn't offer to buck one time.

It could be that you were asking him for more than he was comfortable giving. I know we want our horses to do what we ask when we ask, no questions, but for some it takes time getting them to that point.
My mare used to buck every time I wanted her to lope and never any other time. It was merely a confidence issue. She did not feel comfortable with what I wanted her to do, not because she was afraid to run but because I had insisted upon it.
I know it sounds silly and she should have just done it but horses are not machines. They have emotions that can seem ridiculous to us at times. Sometimes the littlest, seemingly most insignificant thing can upset them.
It was also quite a while before she would even lope on the line for me when I asked without pulling but now she does is perfectly and the only time she bucks when running now is when I push her too hard off the get go when she is not expecting it or if something else is bothering her like the tack or if the horse flies are super bad.
This of course was only achieved in time by never giving up and taking every little bit she gave me. And this was a horse who was 14 when she came into my hands and had had several owners over the years. In other words, a horse you would think should be perfectly comfortable being ridden.

Thank you for the info. Rebel is only 5 so it sounds like I just need to put some time on him and work him some more.

Anyone else?

Will he canter without bucking if you are a bit more gentle in asking?
I would gently squeeze to request the canter rather than kick. You might want to use a crop (gently) on his neck along with the squeeze to push him along. Some horses are just a bit sensitive to excessive leg pressure.

Maybe refining your aids so you squeeze instead of doing the kid-kick would help. I would probably kick out or buck too if someone kicked me to go faster.
Posted via Mobile Device

My six year old gelding bucks when he is kicked at a run. It was shocking when he did it, because my mare can be kicked and kicked and kicked when she's running and she does nothing.

Some horses prefer it if you ride differently than you are used to. Well, I'll use my two for examples...

My mare knows that a kick to the sides and a yell of the word "Hike!" means to go as fast as she can, give it her all, etc... She doesn't mind being kicked at all, and I can ride her at a run with a lot of motion (swinging the reins up her neck and back down with my mar motions, kicking her, moving in the saddle to encourage her, etc...).

However, my gelding, is much different. He hates to be kicked and will buck when he's running and I kick him. He prefers for me to sit very still and not encourage him with movements. If I kick him while he's running and he doesn't buck, he will show his displeasure by slowing down to a canter or trot and ignore my urges to go faster. He will, though, give it his all if I stay perfectly still on his back, lean forwards very slightly, and click or kiss to him. That's how he knows to go full tilt into a run, and that's what he likes.

Some horses just prefer different things. I would experiment and find out what types of cues your horse prefers.

Aug Issue of Horse & Rider has an article in it about horses that buck at the lope.