I am a first timer trying to choose a new ebike. Two EBC bikes I''m considering are primarily the model R, possibly X. I live north of Atlanta,Ga.it is hilly in places. I am older, 69 and a big guy, 255 with some knee issues at times and hip replacements.. I would expect the 7 speed to help with climbing. I am just curious about how, if there is much change in acceleration, and especially top speed with 7 speed vs single speed. I will be riding mostly on the road, and this is not a very biker friendly area. A little more speed is a good thing. I'm also considering a Biktrix Stunner. It's been about 15+ years since I rode a bike much, I did ride a motorcycle for about 30 years.