Sorry to have been silent for so long, wasn't getting notifications until this morning. Thank you to all of you who have posted so much helpful information (most of you ). Since I posted, I have found out about Adaptive Biketown which fits and rents adaptive bikes and ebikes and happens to sit right at the head of one of my favorite rides from Portland to Oregon City. So, while she is recovering, we will make use of that. Thank you all for your help!