Daft question about bit ring size

[McFluff]

I'm replacing my mare's looks ring snaffle and wondered if I could use the 55mm ring size (which is meant to be used as part of a double) rather then the 70mm size.
She is a cob, but has a neat head, and I find the current bit rings rub her noseband unless I fit the noseband a bit higher than I like (noseband is loose).
Does the ring size affect the action of the bit?
I can't seem to find anything about this, so would appreciate any thoughts.
Thanks

 

[be positive]

There is no reason why you cannot use the smaller ring size, it will look neater, probably stop the rubbing and the only difference will be slightly less movement which should be no problem, I sometimes use a bradoon on horses with small mouths as it looks so much better.

 

[nicelittle]

We used a bridoon snaffle on a loan ISH. He had a very big tongue and was not happy with a standard snaffle mouthpiece thickness.
I think it was also slightly more harsh as it was considerably thinner.

 

[McFluff]

Thank you both so much. That helps.
She has a small mouth, low palate and big tongue, so trying a 12 MM thick bit. Appreciate it is harsher, but nicer if it fits better!
Using the bit bank, so can always change...

 

[Sugar_and_Spice]

Larger bit rings help a little with steering. If that's not a problem then you'll be fine with the little rings.