Roxy, congrats on riding 40 miles! You beat me by 1 mile- I rode 39 yesterday (my longest ride since starting to ride this summer).

Don't fret too much about the daily scale bumps and dips- that's why groups like weightwatchers only have you record your weight once a week. I started riding to get of my plateau, and it really has helped- I'm sure it will for you. I cannot imagine losing 2 lbs a week though- sometimes it's half a pound.... or less.

Sounds like you have a lot of challenges as well as ambitious goals- good luck with it all!