I recommend something w/cadence, also something compatable w/ your rear wheel (trainer) I have a vetta vl100 which fits that bill and its awesome. I also have a cateye strata double wireless which is also plenty functional but Im not crazy about the neck mount and mode change action.
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2010 Kestrel RT900SL, 800k carbon, chorus/record, speedplay, zonda
2000 litespeed Unicoi Ti, XTR,XT, Campy crank, time atac, carbon forks