electric bikes?

Well for us we are in our mid 60's and live in a mountainous area not much flat.
We did ride regular bikes up until now. When you got knee problems, I have had a hip replacement (the other will be replaced soon) they allow us to have fun and still be on 2 wheels.My wife and I were avid Motorcycle riders for years so this keeps us in the wind now.Arthritis is no fun.