What to try a bitless bridle but dont know which one to try?
ratings below - *1 poor - **2 average - ***3 good - ****4 excellent

SIDE PULL      - ***3 steering  - ***3 stopping  
                      - suitable for all riders from beginners to experiened
                      - most horses who are easy to handle in a halter will suit this bridle.
                      - noseband designed to prevent from slipping left/right
                      - the side pull design is the simplest form of bitless bridle, .
                      - being similar to riding in a halter .
                      - the reins connect to O rings on the sides of the noseband, 
                      - and uses mainly nose pressure for control

CROSS UNDER  - ****4 steering  - ***4 stopping  
                             - suitable for all riders from beginners to experiened
                      - suitable for all types of horses except some who are head shy.
                      - design uses nose, head, jaw and poll pressure
                      - the cross under design uses all over head pressure, .
                      - the reins connect to O rings on straps that cross under the jaw, .
                      - this bridle is more effective in turning than the side pull, .
                      - but some horses or riders dont like the poll pressure. 
                      -

HACKAMORE    - **2 steering  - ****4 stopping  
                              - not suitable for beginners, or those with heavy hands.
                      - Mainly suitable for horses who are head strong or hard to pull up.
                      - unique metal side pieces provide a soft hackamore action
                      - 
                      -

ROPE BOSAL- ***3 steering  - ***3 stopping  
                             - suitable for all riders from beginners to experiened
                             - similar to a hybrid of the cross under and sidepull
                             - certinally the cheepest way to try bitless bridles.

WESTERN - - ***3 steering  - ***3 stopping  
                             - suitable for all riders from beginners to experiened
                             - Very similar to the cross under but with a wider noseband
                             - noseband is wide and fleece lined so very soft

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Bitless are suitable for most horses, great for those with sensitive mouths or hard mouths. A Bitless Bridle is a Different feel for the horse, and they cannot evade the pressure, and there is no pain from the bit (for those with senstive mouths or bitting problems due to conformation) In my experience (about 40 horses trialed so far) over 90% of horses work very well in a bitless bridle, most will straight away be able to be ridden bitless, a few of them with need a couple of minutes to understand the new feeling. I have had 2 horses who i could not ride bitless, 1 was sensitive around the head and head shy, the other didn't like the head pressure from an old injury to her jaw.