My wife is shopping for a comfort bicycle. The last time either one of us was on a bike was decades ago. She really thinks the single speed 2006 Raleigh Retroglide with coaster brake is "...just so cute " but it only has one speed....she "thinks" she wants a seven speed. In here defense she has test ridden a single speed, three speed and seven speed. I would really like to make her day and bring the Retroglide home retro-fit with a seven speed set up...is this practical / possible?