*snootyvoice*
Ewww... I find the X-Pro complements the carbon fiber in my shoes. They are 0.7g lighter than the old ones, old sport.. The Classic Chrome setting makes every strand of Carbon come to life, don't you think?

*/snootyvoice*

Seriously with the X-100 even more so than the X-Pro A small handle bar bag would do the trick. It's right there and ready when you need it. I've carried my Lumix GX7 (same size as my X100f but slightly less costly to replace) on a long camera strap slung across my body while riding around. That worked fine.

While probably the safest solution, i think a camera back pack would be overkill for your use and, IMHO, when I have a camera in a back pack the camera tends to STAY in the backpack.