Mouthpiece Rims - GR Mouthpieces

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Mouthpiece Rims

GR School
The rim is the part of the mouthpiece that comes in contact with your chops. 
It will determine how your mouthpiece feels and to some extent, how it responds. 
Therefore, it is imperative that you get it right!

The rim area has been one of debate and mystery. 
We measure our rims and cups using the Mouthpiece Design Parameters unique to GR Technologies.
 
  • We have defined the entire mouthpiece mathematically, so we have a huge advantage when it comes to measuring.  
  • Every parameter is important and will effect the feel of the mouthpiece on the face.

  • The rim Bite is the radius between parameter r1 and r2. Note on the drawing Rb. This is the bite radius.
  • A smaller radius will give the rim a sharper feel. 
  • This will aid attacks, but too sharp a bite may be uncomfortable. 
  • A larger radius will have a softer bite. 
  • This may feel very comfortable to some players, but may make clean attacks more of a challenge. 
  • A softer bite may also make the cup feel slightly wider.




We use r2 and r4 to measure the cup diameter.
  
  • When using r4 the diameter is measured at a distance  of  .032" from the rim plane.   
  • When using r2 the diameter is measured as the point the bite radius (Rb) ends.  
  • See Cup Diameter for information.

  • Rc, Rb, and Ro are the radii that make up the rim.  
  • Other important parameters are r0 and r02 as these represent the highpoint and outside diameter. 
  • These parameters are used when defining the rim.

Outside Diameter
This is the diameter measurement from the outside of the rim on one side of the mouthpiece to the outside of the rim on the opposite side of the mouthpiece. 
Parameter r02.

Rim Contour
The blending of the radii around the rim makes up the rim contour. See below. The Rim Contour starts at r02 on the outside of the mouthpiece and ends at r2 at the start of the cup.
 

Hint! Use manufacturer's descriptions and comparison charts as a very general guide and starting point.
Only GR Playing Tests will be the definitive method to determine proper match between player, mouthpiece, and instrument.
Rims are usually classified into four very general categories:
1) Wide
May feel very comfortable and aid endurance, but may make flexibilities a challenge. Wider rims have an anchoring effect and may aid in distribution of mouthpiece pressure in the upper register.   Usually if a rim is too flat or too wide it will impinge lip vibration and cause a thin sound.
 
2) Narrow
May aid flexibilities and attacks, but may be uncomfortable to some players. Too narrow a rim could have a "cookie cutter" feel if a player uses too much mouthpiece pressure, but to some, will give great flexibility and precise attacks.   If a rim is too narrow or to sharp is will hurt endurance or cutting could occur.
 
3) Flat
The larger rim area of the flat rim will aid endurance and have an "anchoring" effect, perhaps at the expense of lip flexibility. Some players will greatly benefit from the comfortable feel and anchor of a flatter rim.   Usually if a rim is too flat or too wide it will impinge lip vibration and cause a thin sound.
 
4) Round
Round rims have a very secure feel and may aid flexibilities, but may hinder endurance. The reason for this is that with a rounder rim, there is less effective rim area contacting the chops. This is a similar situation to the narrower rim, however, some will excel with a rounder rim.
The rim contour is made up of small arcs or radiuses. The three that make the most impact are:
 
1) Inside or Bite Radius-Rb
A smaller radius will give the rim a sharper feel. This will aid attacks, but too sharp a bite may be uncomfortable. A larger radius will have a softer bite. This may feel very comfortable to some players, but may make clean attacks more of a challenge. A softer bite may also make the cup feel slightly wider.
 
2) Crown Radius-Rc
This radius determines the roundness or flatness of the rim. This may also be referred to as the "high point" of the rim. The high point (r0) will also determine the feel of the diameter of the cup. If two cup diameters are the same, the mouthpiece with the high point closer to the outside may feel larger.
 
3) Outside Radius-Ro
This will determine how wide the rim feels on your chops. A smaller outside radius will make a narrow rim feel wider, especially in the upper register, where more mouthpiece pressure is experienced. This will give you more rim area on your chops if you add mouthpiece pressure.

  • Rim contour is a very personal choice. Careful experimentation is the key. Try to change only one aspect of the rim at a time. Remember what works for you and keep notes. You must know what has worked for you in the past to move to the next level.

  • The blending of the radii around the rim makes up the rim contour. The Rim Contour starts at r02 on the outside of the mouthpiece and ends at r2 at the start of the cup.

Additional information!
The plating on the rim will also affect player comfort and resonse!
Whether you choose Silver, Gold, Rhodium, Lexan, or Delrin Plastic, each will have a different grip!
See "Plating" for more.
 
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