Quick Bit Question

[teddypony]

My horse is currently in a single jointed mouth piece which is 5" i am thinking of swapping her into a cambridge mouth kimlblewick, do i need to change the size of the bit, i always get confused with different mouth pieces and bit sizes :rolleyes::o (swapping bits due to riding a giraffe most the time and want something to help stop her throwing her head up) -oh and im changing from a gag, so i think it is mainly due to the leverage of the bit which she hates
Thank you :)

[JustJas]

I thought the bit size was the size of the mouth and only a loose ring bit needed to be bigger.
Not used a bit now for 2 years so not best to advise. My mare threw her head around and just hated bits I tried all types- straight, jointed, lozenge, cambridge port. Jazzmyn prefers a bitless scrawbrigg- no use for showing but ok for hacking.

[montys helper]

my boy use to throw his head up and around when he got excited so i got a bungie lunge and hes fine now

[Joyscarer]

I swapped to a cambridge mouth and stuck to the same size as the french link she was in and it was fine.

An extra 1/2 inch to go up a size would have been too big.

I'd love to know how you get on with the swap. My mare much prefered the cambridge and was imediately less fussy through the mount and happy to accept contact which she wasn't in jointed bits.

[teddypony]

french links ( i think ) are half a size bigger than your normal bit size? So should i go up a half a size or leave it. I had her in a pelham that was 5" (rugby pelham) which was pinching and way too small. But her current bit is definately 5" (i have measured it)
Joyscarer, i will do, im interested to see myself:)
ETS: a lungie bungie isnt an option, i dont want to force her head into the position when clearly it is due to being unhappy in the mouth. She is probably honest enough to accept it (or stroppy enough to have me off lol)