Oops- forogot to finish the sentence ;
"222 (small 2) is the inside diameter of the chainstay ports in mm.(22.2) with Nervex, whole numbers were associated with"
Should read ...associated with French shells - typically 18, 20 & 22 mm, and for English threaded shells (ID's of 19.05 & 22.2 mm).
Bob Reid
Stoneaven
Scotland