Hi all .. As part of my new commute, I will have to drop my daughter off at school. I'm getting a Thule 983 Spare Me rack that I want to lock my bike to. I plan on biking from there. I'm worried about securing it to the rack. I'll have to leave it while I walk my daughter to her class and...

When out in the urban area what do you do about the security of your saddle/seatpost?