I am putting together a electric recumbent trike that will have gear selection to the drive wheel. I will be using SLA batteries for now so weight is something I need to think about. Here is what I am interested in doing: top speed of 20-25 mph and pretty good range for around town, maybe 20 miles with very limited peddling and mostly level terrain. I thought for longer trips I could add a trailer carring batteries connected to the main system and may installing a switch easy to reach to activate these trailer batteries. So far my thoughts have been a 600w or 900w 24v motor or moving up to 36v. I have been looking at motors that may fit between peddle cranks which I need for this application. Somewhere along the line I think I was warned that a higher powered motor is not good at slower speeds, say, 7-10 mph. So that is something I don't know about. I don't want the bike to be a wimp, but also don't want to go into "overkill". I have been leaning toward the 600w 24v approach, thinking the gearing will be a big help for performance and I could carry more batterie for more range than with 36v. As you can tell, I am not sure about the best way to do this. I already got some good help on this forum from Professor and Johnrobholmes regarding another part of this project. So, thought I would try again with these questions.