How to ride under obstacles
10 cm from the saddle would be possible if you are talking about XC saddle height and the handlebars are lower than the seat.

One way is to do this:



Another way is to bend and go very deep:


knees bend pointing outside
hands totally straight to the bars so your body moves backwards
back totally straight
position your body so the saddle goes exactly between your head and your left or right bicep (whatever works best for you)
look ahead