Are you measuring the full diameter of the rim, or just the bead set diameter? It is the B.S.D. that should be 571mm. (See this http://sheldonbrown.com/tire-sizing.html)
(I can't see your photo b.t.w.)
@s.walrus started
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Are you measuring the full diameter of the rim, or just the bead set diameter? It is the B.S.D. that should be 571mm. (See this http://sheldonbrown.com/tire-sizing.html)
(I can't see your photo b.t.w.)