Transitioning to a New Bit 

"Never expect more from the horse than the time you have to give him. Training requires time, patience and repetition." 
The Myler Brothers

Once you've selected the bit your horse needs, it's time to introduce it and evaluate its effects. Don't expect the bit to be a magical solution to all of your problems or that it will train your horse for you! 
We recommend that you introduce any new bit in a safe, closed enviroment, such as a round pen or arena. There ar a few exercises we recommend as transition exercizes; Vertical flexion and lateral flexion. Both exercises are shown by Dale Myler in the video below. To practice vertical flexion, stand next to your horse's head and lift the reins at the withers until you make light contact. Hold the contact until your horse gives to the bit, even slightly, then immediately release. Do this on both sides until your horse is relaxed and flexing at the poll. 

To practice lateral flexion, stand next to your horse and lift the rein, but ask him to bend his neck and turn towards you. When he does, release him immediately. Perform this exercise on both sides until he is relaxed and flexing laterally. Then repeat both exercises from the saddle. 

The first rides with your new Myler Bit you want to make it for your horse a bit more easy going. It takes time for your horse to become accustomed to the new bit and this is depending on the horse's experience and dispostition. For a horse with experience under saddle, expect to spend at least 45 minutes to an hour on the initial introduction, but plan at least seven to ten normal riding sessions to fully transition him to the bit and evaluate his response. If the horse is green and this is his first bit, then obviously it will take more time and planning to introduce him to the bit and possibly several training sessions before he is accustomed to the bit. 

Also check the adjusting of the bridle, evaluating how the bit fits and adjusting the curb strap or chain.