How much more compatable, really, is the 4550 with a 9 speed set-up than a R600 or R700? Some searching of this site leads me to conclude that one of the '10 speed' cranks will work just fine with my 9 speed 105 components. In other words, how much difference is there between 9 and 10 speed chainrings?
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"The older you do get, the more rules they're gonna try to get you to follow. You just gotta keep livin', man, L-I-V-I-N." - Wooderson
'14 carbon Synapse - '12 CAAD 10 5 - '99 Gary Fisher Big Sur