I use a wireless Cateye V2c. It has a single sensor on the chainstay, with a magnet on one pedal post and one on a rear spoke. I get cadence without a second sensor, which is what sold me on this model. I have no connectivity issues whatsoever, and have a really big bike (68ST, 60TT). The current versions of the wireless computers use the 2.4Ghz frequency, same as most WiFi, and have a greater range than the older computers. There is no longer a need to run wires, nor limit where you put the sensor(s).