Here's a hook for hanging up your bike. It is approximately 11mm in diameter, rubber coated and has a 5cm long wood screw at its base. We set our garage up with hooks about 4 years ago and they are still going strong.

Dimensions:
22cm total length (top of rubber to base of metal thread)
10.5cm external width (from outside of rubber to outside of rubber)
Thread: O.D. is 11mm, I.D. is 9mm

Installation
It will need to be screwed into an appropriate piece of wood or stud, do not use hollow walls! Pre-drill a 9mm-10mm hole into your wood and then screw this hook in. It also comes with a nylon plug, in case you want to use a solid wall.