Learn About Trumpet Mouthpiece Deign and Construction - HEREThe rim contours of each diameter are unique. Although each rim is consistent within it's size range (ex., Curry 1C rim contour is the same as Curry 1Z rim contour), it is much different than the 1 1/4 rim. For example, if the Curry 1 1/2 C rim is the most comfortable rim you've ever felt, but seems a little "tight", it is wrong to assume that moving to the 1 1/4 size would solve that problem. The correct solution would be to get a custom mouthpiece using the 1 1/2C rim contours. The "tightness" issue could be solved in a couple of ways. The rim profile could simply be moved a few thousandths to the outside, or perhaps the bite radius could be increased which would also give a few thousandths more room. There are others ways to get the "feel" you're looking for, but you shouldn't be concerned with that. I'm the mouthpiece makerInner diameter "numbers" mean very little. Most manufacturers reference charts are expressed in both inches and millimeter sizes. One "major" manufacturer's published "numbers" are totally wrong! In fact, the millimeter conversions in their manual do not match the decimal numbers! And, they've reprinted the same mistakes year after year! The point I'm making here is that every manufacturer has different criteria for measuring the inner diameter. My personal criteria for measuring the inner diameter varies from rim to rim. In my 30 plus years of trumpet playing, I've learned that the feel of a mouthpiece can vary from rim to rim. The spot on your face where you "feel" a 1C rim is much different than the "contact point of the 1 1/2C rim. Although they only vary in "size" by a few thousandths of an inch, the difference in feel can seem like a country mile. Don't get hung up on the numbers too much. If they do matter to you, buy some dial calipers. A good enough pair (Chinese-made are just fine) of calipers will run about $60 in an industrial supply store. By the way, of my several thousa
