i use one if this saddle bag for my road bike but the large size. can fit in an iphone11, a spare tube, multitool like the one you have in this video, some patches, a small wallet for cash. all the items are packed inside a small plastic bag and i put a cardboard between the iphone and other items to prevent any damage on the phone. make sure the strap is tighten well as not to rip off the seams.
![30 ชั่วโมงคนเดียว บนรถไฟชั้น 3 โซเวียต [Around The World Ep. 2]](http://i.ytimg.com/vi/MlE9boAVqDA/mqdefault.jpg)
I have the same bag but without the velcro strap for the seat post.
i use one if this saddle bag for my road bike but the large size. can fit in an iphone11, a spare tube, multitool like the one you have in this video, some patches, a small wallet for cash. all the items are packed inside a small plastic bag and i put a cardboard between the iphone and other items to prevent any damage on the phone. make sure the strap is tighten well as not to rip off the seams.