My wife and I spent several hours with the owner (Chad) of Spin Bicycle Shop in Lansing MI yesterday test riding trikes for the first time. As long time bike riders we very impressed with the trikes and even more so with Chad. Following two knee replacement surgeries (resulting from knee injuries skiing) my wife was able to get back on her bike this spring for the first time in two years. Unfortunately, while she has no trouble walking, climbing stairs, etc. the way she described her bike riding to friends Is that she has a "hitch in her get a long." Each revolution with her right knee would kink and cause a pause in the stroke and a slap in the chain. After a couple hours on the trike yesterday she and I were "SOLD. She had no problems (pain or even discomfort) in either knee! We tested the Rambler 8 speed, The Tour II Base, and Sporster x30. We ordered two Sportster x30s and will pick them up two weeks from tomorrow. We are both "geeked." It is such a pleasure for me to see the anticipatory excitement in my wife. We begin a three week vacation in three weeks and now plan to travel the state of Michigan hitting as many trails as possible (primarily northern Michigan) on our new Terra Trikes!