Originally Posted by lucid
Despite weighing almost the same, the 19" rims will have slightly more rotational inertia than the 18" rims as the majority of the rim mass is distributed further away from the rotation axis (by 0.5" in this case). But that effect would be so small that one cannot feel it.
the 19" rims MAY
have slightly more rotational inertia - key word MAY. the forged 19 rim may wigh less at the outer rim. the spokes may wight less. the 18 inch tire could wiegh more. we dont have specs on the moment of inertia of the two do we?