I do a lot of these event/charity rides. So far, I've done three this year and I'm getting ready to do the MS 150 next month. You will warm up quicker than you think once the ride starts. Don't worry about leaving your bike unattended at the SAG stops unlocked. Unless your bike runs in the $9,000.00 and up range, you will see quite a few bikes worth much more than yours. Unless your bike is very unique, no one will mess with it. Just make sure you have plenty of water to get you from stop to stop, take some gels and granola bars, don't ride as if you're in a race and enjoy the ride. Your goal is to finish the ride and have fun doing it.