Detraction from C&V aesthetics? Hmmm, depends on the mood. I get a kick out of technology and the wiz bang out of a smart phone for near zero cost, but only use maybe 25% of my time cycling. Sometimes I attach to the bar or stem with a Nite Izes mount, other times in the pocket or handlebar bag clear map window.
Often don't mount anything, though always have a pair of lights ready and a whistle in my hydration pack. Blinkies on the helmet.
Also enjoy old school gizmo's and or mixed with other. Example is on this Trek 520. O-ring drive and darn accurate. Other side is a homebuilt bracket attaches to any axle skewer and holds a USB chargeable tactical flashlight.
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DSC_1021 by
carrera247, on Flickr[/IMG]