Techniques for safely leaving a bike for 1-2 minutes in a safe-ish place In the last year, 3 of my friends got their bikes stolen by leaving them "just for a minute" in front of a shop "while watching them through the window".

Nevertheless, sometimes I do the same. Maybe I didn't plan to bring a lock, and need to jump really quick to somewhere. Maybe there is a security guard nearby, or a bank camera. Maybe I am just too lazy to to dig the lock out of the bottom of my backpack, and have exact change to grab a beer. Maybe there is nowhere to lock to in a 100m radius.

My question is how to increase security in these dangerous situations. 

A friend shared with me, that he shifts into the lowest gear - that way if someone tries to ride away the bike, it will take him quite some time. On the other hand, something that I do, is lean my backpack against the bike or even strap them together. IMO this makes riding off with the bike a little more difficult, while risking my backpack along with the bike.



Conclusion:

Currently, the "derail the chain off the front chainrings" sounds most sane to me, because I can do it with my shoe, without getting oil on my hands. Still, carrying the lock on my waist, under the backpack belt, is the far best solution. Why do I even put it inside the backpack?
Firstly, these suggestions are only going to make it slightly harder to ride away with your bike. I've heard the most common thefts involve grabbing the bike or bikes and slinging them into the back of a van, in which case it doesn't make much difference.

But against the casual opportunist/errant kid...


Have a QR parts and remove them - saddle, pedals?, bars?
I use a small velcro strap to make parking easier. This goes around the bars and pulls on the brake lever on when parking, makes it easy to lean it up against a wall without it wobbling. This might stall someone not expecting it.
Derail the chain from the front rings.
Best of all, get one of those super-convenient rear wheel/frame locks as below:



As long as you've got your key with you - some of them stay in the lock when it's unlocked - it's easy. No more excuses!