Thanks for the responses, everyone. To clarify:
- It's a steel frame and I've been in contact with the manufacturer (Bike Friday). They think it will bend back fine.
- That mud is, as choddo guessed, is from the last ride that precipitated this fine mess. This was a month ago, right before the holidays. I dejectedly trudged home and put the bike away. I purchased the tool after the new year and am ready to give it a try.
- I have no idea how or why the cassette stayed clean.
- I have not checked to see if the wheel is still true. I will use a consistent reference point, i.e., the part of the rim with the valve stem. I'll likely check trueness first.
Thanks again.
