I'm really a dummy when it comes to anything mechanical or electrical! If I understand correctly, if I buy the electric hub motor for my Electra Townie, I will no longer have the gears that came with my bicycle available for pedaling?

I need to keep the gears that came with my bicycle, so I can still ride my bicycle with no motor as often as possible. I need the exercise and enjoy riding, but also need to commute to various job assignments where there is no bus service, and too far for me to pedal (10-15 miles each way).

I want to get something that will last many years, and allow me to attain speeds of at least a good solid 35mph (45mph would be better, so I could ride on the country roads where the speed limit is between 45-55mph), with my weight, plus groceries (will not be riding fast with groceries!!!, only around 10mph then!).

When I go to work, my weight is around 210, plus my large backpack, which normally weighs around 15 pounds. Groceries will add another 15 pounds, sometimes more ....

So, I need a good quality motor that will easily carry over 250 pounds, reliable, effecient, long lasting ..... I've been checking around on different websites, but am still a bit overwhelmed ... !!! Help please ... !!!! Thanks!