[jhautz]

No it doesnt overhang. It comes almost exactly flush to the back of the threaded area. The first speed gear goes on almost exactly flush to the front of the carrier.

Here are a few pictures that show the assembly a little better than the pictures in the store. This is the 16T first speed and 21T 2nd speed gears and the 2 speed adapter.

EDIT: The gear faces themselves are 6.8mm wide. The first peed gear has a collar addtached to it to space it from the 2nd speed gear