There aren't that many days that we need a jacket here in Florida, especially this year. I usually carry some long shoe laces in my saddle bag that have several roles. When I do wear a light jacket or sweatshirt and it starts to warm up, I roll the jacket up and tie it to the saddle bag with the shoe laces. Works really well and you don't have to give up a jersey pocket or have a large bulged item against your back.