Known for not only their powerful line of mountain bikes and specialty bikes—cruisers to fat—Bulls also has a versatile line of urban models. The Cross E Wave comes as one of their more affordable options at roughly $2,800, but at 20 mph can still range for up to 134 in optimal conditions with everything you’d expect (fenders, lock, lights and adjustability). The entire family of Bulls e-bikes has specifications built for any scenario.
In a friction drive motor, a small, solid wheel rotates against the side of the tire in order to drive it. The first motorcycles used the same concept, with a motor mounted above the front wheel. The problem is that the drive rubs at the side of the tire. It's inefficient, and it quickly wears the sidewall away. Tires need to be replaced every couple hundred miles. For this reason, you'll seldom see electric bikes with this type of drive anymore.
For many bikes, battery range is more important that total power (because they're all pretty powerful). You want a bike that delivers a range long enough for your rides at the power levels you want. Most e-bikes will have three to five levels of assist kicking in anywhere from 25 percent of you pedal power to 200 percent boost. Consider how fast the battery takes to recharge, especially if you'll be using your bike for long commutes.