Wireless ones do work Tony, though they can suffer the odd interference failure like any radio device. Not serious though, just missed beats, but I'm personally not keen on having a regular two battery replacement situation.
In fact the cycle computer that 50cycle fitted to the Agattu that I tested was very unobtrusive. The black wire didn't show up on the headstock, and they'd neatly coiled some of the spare cable into a slim spiral to allow free steering and wound the rest round the left hand brake arm where it wasn't obvious. Since I like the Cateye Velo 8 cabled model, I'd be happy with doing an installation like that.
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