Originally Posted by EricDJ
It is likely set for the wrong tire size. Some new bikes come with a 700x26 tire that isn't even listed in the owners manual.
Speaking of interference, mine was a pain to set up but not due to the unit. Something in the area of my stereo and TV interferes with the unit so when I was setting it up, it couldn't communcate between the sensor and unit. When I tried later across the room, it worked great. I can spin the wheel near the TV and nothing registers at all.
See. And you mom always said TV ws bad for you
. Seriously TVs and stereos have a lot of RF (radio frequency) circuits generating radio waves. Even with FCC shielding there is leakage to interfere with nearby wireless bike computers. Same reason you must not use a cell phone in a hospital. Also the power supply in a HID bike light that jumps battery voltage to light voltage can generate RF. If you really must have the bike near the TV try a wired computer. And you might need to put shielding on the wire.