Rad bikes are very hard to beat for the price.
There are three common types of electric motors in use right now
1) Direct drive hub - these look like giant Frisbees on the front or rear wheel, very simple, just a large generator, no mechanical parts
Pros- Very efficient at their cruising speeds and (best for) high speeds & long distance, typically 16-28 mph range. Can do regeneration i.e. regenerate power when braking and going downhill, when equipped with a proper controller. Very reliable. Either the motor or pedals can get you home if either break. Easy to install on front, moderate to install on the rear.
Cons- Very inefficient for slow speed cruising. Not good for steep hills, they will draw a lot of amps and output little power at low rpms. Large and heavy. Over 500 watts should have a steel dropouts and beef up plates.
2) Geared hub- These are about half the diameter of the large Frisbee direct drive hubs, and usually a bit fatter. They are basically a smaller direct drive hub tied to a mechanical gear reduction, 3 plastic planetary gears. Easy to install on front, moderate to install on the rear.
Pros- More low end power than a direct drive hub, smaller and lighter. Better for hill climbing than direct drive, not for steep hills. Very easy to install. Either the motor or pedals can get you home if either break
Cons- The plastic gears can strip or wear out over time (not common), not quite as efficient as a direct drive hub (close), no regeneration (they freewheel). Over 500 watts should have steel dropouts and beef up plates.
3) Bottom bracket mounted- These externally mounted motors (factory bikes have internal on some) directly drive the chain from the pedal cranks.
Pros- Incredible power as you can use the bikes gears to multiply torque. Excellent for steep hills. Must have for really hilly areas or very heavy towing.
Cons- Wears out the driveline faster, increases power several times more than a human can do through the chain rings and sprockets accelerating wear. Not as efficient as the hub motors, will use more battery power for long distance riding. If the chain ring breaks you are stranded. Moderately difficult to install.
You can purchase quality motor kits around $400 and a good battery around $400 and add them to a bike that you really like. Personally, the Rad power bikes are so well made and inexpensive (for an ebike) I would just go that route for anyone but a real ebike enthusiast.
Sondors makes some really inexpensive ebikes, about $600. Those would be good for flat paved or very smooth dirt roads, not boondocking dirt roads.
I've owned several ebikes and have used them extensively. Any questions just post.
