Two different horses, two different issues, and I'm needing help with both.
Horse One is a 11yo Arab/QH. Has made a LOT of progress in the past few months, and has really figured out that using his back and being through is way easier. However, his mouth is not exactly soft, which is something we are working on. He tends to brace and lean on the bit, especially in downward transitions. We do lots of half-halts, lots of leg, and I regularly lighten contact to force him to carry himself (works like a charm). We have tried a 3 piece loose ring, a Myler D ring, a Myler Baucher, and a plain, single-jointed loose ring. He improved with the Baucher, but only slightly. I know the bit is not going to completely fix him, but I am curious if a different bit will change this habit. Some rides when he's feeling extra good he braces more, and I feel that when I am half-halting a lot he just tunes me out after awhile.
Horse Two is a green 8yo TB gelding. The way he is built, evading contact by arching his neck is super easy. He's very sensitive and light in your hands, but still learning how to stretch into the contact. He didn't care much for the loose ring 3 piece, and is currently in the Myler D ring and seems happy. However, would a loose ring encourage him to accept contact and stretch more?
The horse that seems happy I'd leave alone.
The leaner needs trot halts... Lots of them. Prompt, even with a whip in each hand get him launching into that trot with some power, and bring it back to a halt before he loses that balance. Praise and throw a party when he doesn't lean.
Riding in shoulder fore will help a lot too.
For the TB, I would try a nice fat bit (18mm-21mm) with a lozenge in the middle. Not necessarily a loose ring cheek since the added "wiggle" of the loose ring may discourage him from taking up a contact since he's still learning to take up/stretch into the contact.
My horse was very light in the contact like yours and I found that simply increasing the thickness of my bit from a 16mm to a 21mm made him stretch into the bit more willingly and consistently.
For your first horse, I don't think changing the bit would be a good idea in the long run. Personally, I think it sounds like he just needs some clever exercises to get him to loosen up throughout his entire body and work through his haunches (not just half-halts, get creative!). I feel as though "bitting up" would only mask his habit of bracing, not proactively work to fix it.
I definitely need to get the horse that leans/braces better on the aids. Lately he's been low man on totem pole when it comes to the schedule. I'm not looking to bit up, just looking for something that he may not be able to lean on as heavily. I ground drove him in one of the new Prof. Choice single joint loose ring snaffles tonight and he didn't seem as heavy. He was also very full of himself, so we'll have an official test ride tomorrow.
For the TB, I never thought of going to a fatter bit. Duh. The three piece loose ring had a lozenge, but he wasn't too thrilled with it. I really like the way the Myler D moves, so I'll look at the tack shop to see if they have a fatter version. My trainer may have a fat double jointed full-cheek.
Time to raid the bit bucket!! Thanks for the help!
My Arab was very shy about the bit when he started out. He loves his JP Korsteel eggbutt oval mouth. They're relatively inexpensive (around $30). I have one with a copper lozenge and one that is the same silver colored metal as the rest of the bit.
I initially got him a Myler and he HATED it, backed off and did everything in his little Arab power to evade it. The fatter JP Korsteel he was MUCH happier with. He also likes a mullen Pelham (he doesn't need the 'breaking power'...I just wanted to try a mullen mouthpiece and I like the look of the Pelham for hunting) with a similar thickness.
my half arab goes in the JP oval mouth loose ring. I think its more about taking a good connection/stability and getting the horse in front of the leg then anything.
My horse likes to rush and brace but the answer has been more training and keeping it really simple.
Forward-straight-even in both reins-connection.
Agree with Candysgirl arabs tend to go either too braced or too deep/evade. Its been a constant challenge to work on these basics but my horse in other ways has shown to be a very talented dressage horse. Its just an arab thing.