Truth .
Can I ask you why car and truck suspensions sag over time?FBinNY said:I beg to differ,
This is really a myth. There's no harm in storing a bike with the derailleurs in the slack spring condition so you might as well. On the other hand, there's also no harm in storing it with tight springs.
Metal springs are elastic and do not take any kind of set or get weaker from long periods in the compressed state. If they did, your car would get lower over time as the springs sagged, and scales would need to be constantly re-calibrated as the springs changed their constant.
The tension property of any spring is called the spring constant for the simple reason that it is constant. As long as a spring is not flexed beyond it's elastic limit it will not change dimension or constant and can be stored almost indefinitely in the compressed state.
The only things that might take a set or be damaged from long term improper storage are your tires. Either pump them from time to time, keeping them hard enough to keep their shape, or store the bike with the weight off the wheels.