Cateye makes several low-end models that can suit your needs. the computer can easily unclip from the mount and go in your pocket. They sell wiring and mounts separately too, just in case those get stolen
off your bike.

**Important about the Cateye Strada Cadence** I recently bought this model just to get something
cheap with cadence and found that the only buttons are on the bottom of the computer. If you want
to change what data you are viewing, you have to remove the computer from the mount, press the
button, then put it back on the mount.