Thu Jun 19, 2014 11:23 pm by escher7
As Flywheel says, it would be helpful to know the circumstances of each of your bike losses.
I have a beautiful Italian mountain bike that has served me well for over 25 years, and worry all the time about someone stealing it. I use a fairly common U lock with a disk detainer cylinder, but make no mistake- if you leave the bike alone for long enough someone will find a way to bypass almost any lock. The longest I ever leave the bike is while in the supermarket; at night I take it inside.
If you must leave yours while in classes, I would suggest two U locks, both through different parts of the frame and connected to a very strong post or bike rack. Locate it in a visible area where anyone trying to tamper with it will be seen, and yes, under a camera would be great. Do not use locks that have tubular cylinders as every kid knows how to defeat them. Disk detainers are OK as long as they are of heavy construction. I have also seen new locks with dimple pin cylinders which might be foreign to the common thief.
