My 15 year old gelding had only been ridden in a hackamore since a dental disaster when he was 6 up until a couple months ago when I decided to try a happy mouth loose ring snaffle on him. When I rode him in the bit he tossed his head, acted super nervous, and reared/bucked even though I was practically riding on the buckle. So my question for you is how can I work on lightness, suppleness, balance, and whatnot in a hackamore? Some exercises I can do? He tends to counter-bend on the flat even when I try to use my legs to straighten him out. I know some of the basics of dressage but not much and I really need help!
You don’t say what kind of hackamore. I have several and ride them the exact same way I ride with a bit. If it is a mechanical then you use it like a pelham with two reins.
I also ride dressage with a hackamore of this type and use it like a bit with light contact. My horse goes very well in it and will come up through the wither into self carriage more easily than he does in a bit.
Just curious, how did you introduce the bit? With a horse like yours I would start back at the beginning by having him wear it in the stall and get used to it, then slowly let him get used to being ridden and steered with it before asking for more.