Originally Posted by fourknees
To secure your bike without a lock, if you have a road bike, put your brakes in the "open position" and adjust them for braking (before you are out for a ride). Then when you need to leave your bike on a ride and go inside, put the brakes in the "closed" position and it will clamp on to your wheel.
Couple this with putting the bike in your very highest or very lowest gear, someone won't be going anywhere very quickly.
This won't keep the bike from getting stolen as it can be picked up and carried, but it will slow down someone who thinks they'll just jump on and ride away.
I think these are fine tips. I suggest also using a bungie cord and wrapping it around the bike and post several times. Surely, the thief would need a little time to undo the cord. Of course keeping your bike within eye shot is always a plus!
In some locations in town it is very forested, ideal for hiding your bike. A risk, I know, but if you want to take that hike and have no place to lock it, stash it in a bush instead!!!
Saw this video recently and it is mind blowing http://www.youtube.com/watch?v=6AdugFzCi24
It's about the quantum leap in bike thievery in London England.