I've been doing a little more research, and it sounds like the R/C-type motors need to be running at high RPM, or one may encounter some trouble. I read through a couple posts that described how the gearing is absolutely critical, or motors and controllers will start letting out smoke. I definitely don't want to go with high-end R/C components and start melting them down. In reading about Matt Shumaker's DaVinci drive, it sounds as though it has to be geared low enough that it tops out at 40 mph. I currently ride a MAC motor (8T) with a 12s3p LiPo setup. That system does over 30 mph, and it just sips power if I pedal along with it. Additionally, my legs are partially paralyzed (from a spinal injury), so I can't really give it much assistance.
Anyway, the reason that I am considering building a new system is to get something that will travel at the speed of traffic. When I am going 30 mph in a 30 mph zone, people are still driving like @$$holes and trying to squeeze around me. In a 35, they're usually going about 45. I typically take side streets and bike paths, but sometimes I have to get on a busier street. I feel as though I would be safer traveling with traffic instead of just a little slower. People in cars sure are reckless. I've been a cyclist my whole life. Since I broke my back ten years ago, I've spent most of my time riding handcycles. However, since I've discovered the wonderful world of e-bikes, I've been able to enjoy being on two wheels again. The way people drive around me when I'm on my handcycle is completely different than when I'm on the e-bike. On the handcycle, people give me lots of room and are far more cautious. On the e-bike, they go racing around me and don't give me very much space. I almost feel like carrying a small club so I can smash tail lights when I catch up to them at an intersection. However, I don't think that would make car/bike relations any better. Then again, I think people will always drive like jerks (until one of their loved ones is killed or maimed by reckless driving.)
Getting back to my original post, I've started drawing up some sketches for a mid-drive specific bike that doesn't have any pedals/cranks. I'm finding that it will be very difficult to fit both the motor and a modular battery system inside the frame. Electric motorcycle builders sure have their work cut out for them. Because of the limited space, an R/C motor might make more sense. From the get-go, I've planned on using gears at the rear wheel (either a NuVinci or traditional cassette.) To get a reliable R/C setup, it seems that it would be imperative (if I am going to reach the 50 mph mark.) I think it would be much easier on both the motor and the controller. However, to get the R/C motor speed low enough to use gears at the rear wheel, I would need to have a serious gear reduction. Even with the 4 or 5-to-1 ratios with Mr. Shumaker's drives, it still requires a HUGE sprocket at the wheel just to keep things from burning up. The idea of using a DOUBLE has entered my mind, and I've also wondered about the possibility of making my own planetary gear system. However, those options get complicated rather quickly. I've really been charmed by the simplicity, efficiency, and effectiveness of my MAC hub. I'd like to build a system that has similar qualities but has more top speed. I'm thinking that it may not yet be feasible with the current options available.
