you can safely hang a bike from a single vinyl coated steel J hook, 3 bucks from lowes, etc

ideally you should drill a slightly smaller diameter hole into the exact center of the 2x4 stud, then screw in the hook till you can't hardly turn it anymore with no tool.

if you're not particularly strong use leverage device.

for example:

http://cgi.ebay.com/2-Pack-Storage-H...4074QQihZ016QQ

the pedal and bar only will contact wall surface when hanging sideways (against wall) - so, not much damage if careful

when you move just unscrew, spackle, paint. or leave it there for next tenant.