I am looking for a wireless computer with cadence to mount on a Co-Motion Speedster Co-Pilot. I purchased a Sigma, but when I read the directions, it stated I couldn't mount the sensor more then thirty inches from the computer. In my mind, the best place to mount the sensor is on the stoker's back left crank arm, but this exceeds the recommended distance from the computer. Any ideas on a computer or place to mount this particular one? Thanks in advance for all replies. Also, we just took delivery of this Speedster after 20+ years on an old Gitane. We are totally impressed with the new bike.