http://www.amazon.com/Schwinn-SW654-...5460007&sr=8-1

$14 schwinn wired 17-function bike computer

i had one on my $600 bike and now i have one on my $1900 bike. i absolutely love it. so simple to use and gives me the details that i really wanted to know - speed, average trip speed, miles covered and 14 more other functions (calories burned, etc)