Are you just curious about this as an academic musing or are you serious with your worry?
If the former, you can certainly determine for yourself empirically (or go through some rather ponderous calculations like I did on my boat to determine whether my buoyancy chambers were sufficient for my planned ballast).
If the latter, why not consider attaching a self-inflating CO2 float bag to your bike.
Originally Posted by
70sSanO
In all seriousness, if you are concerned you can buy a mast float that is normally attached to the top of a sailing dinghy. I’ve have used one when the wind picks up and the mast will take in water if it capsizes.
You must have one of those tinkly masts.