Sure you could wrap it a few more times but you will still have problems holding onto the 550 once it is weighted.
The thinnest line I have rappelled was 7mm and it was scetchy.
Why not go try it right now? I bet you will find it virtually impossible.


"On the other hand, a rappel is not something to be set up in a hurry. Ask me about the time I rappelled right off the end of my rope."

Not good. Ever heard of a backup?