If you have an especially good bike, and it means anything to you, keep it. If you still want to get rid of it and move on, SELL it. Universally, things are only worth what people pay for things. If you give it away and it costs the other person nothing, it will have zero value to that person. On the other hand, if you price it right and find a person really wanting it (that's what advertising is for), let them PAY you for it. The bike will then have value to its new owner.