Motor: We have a blog post showing some motor differences: https://www.ebikekit.com/blogs/news/its-whats-inside-your-motor-that-counts Cabling is probably the #1 issue when something goes wrong. Good connectors, good cables, and good assembly (bike shop!) are crucial Strain reliefs on all cable joints! Where you have a junction box or a connector, the stress is concentrated over a small area near this stiff spot on the cable. This can cause small breaks on the internal...
Best Buys are selected in the table below because they work well, come from solid companies and get high marks from users. Generally, buyers can opt to assemble the bike themselves, or pay an assembly fee to their local dealer or bike shop. (Assembly usually includes installing handlebar, pedals, seat and front wheel along with tuning and adjusting.)
E-bikes use rechargeable batteries and the lighter ones can travel up to 25 to 32 km/h (16 to 20 mph), depending on local laws, while the more high-powered varieties can often do in excess of 45 km/h (28 mph). In some markets, such as Germany as of 2013, they are gaining in popularity and taking some market share away from conventional bicycles, while in others, such as China as of 2010, they are replacing fossil fuel-powered mopeds and small motorcycles.
Twice the speed - with half the effort, Optibike has the power. On a test ride in Boulder Colorado, a fit road cyclist was able to climb the notorious Old Stage Road at 10 MPH sitting down with an easy spin on the Optibike. On his ultra light road bike, he had to stand and grind all the way to go 5 mph!!! Twice the speed - half the effort, Optibike has the power.
Durability. You’re paying a lot of money and a costly investment that lasts for a short time is not worthwhile. The electric bike has more components than the common bike, adding the electric motor and the battery; more attention should be put in selection of the bike because of this. You don’t want your electric bike to turn into a regular bike in a short period.
The Brose motor is definitely the most quiet ebike motor that I’ve used. The 28mph model is no different. I also find it to be pretty solid in terms of power. Generally speaking, Bosch motors are considered the most powerful, but with the Brose I actually think you get a lot of power with a more “real” feeling cycling experience. They also give you a 675 watt hour battery pack, which is still unrivaled in terms of a single battery system.
There are individuals who claim to have lost considerable amounts of weight by using an electric bike. A recent prospective cohort study however found that people using e-bikes have a higher BMI. By making the biking terrain less of an issue, people who wouldn't otherwise consider biking can use the electric assistance when needed and otherwise pedal as they are able. This means people of lower fitness levels or who haven't cycled in many years can start enjoying the many health benefits E-bikes have to offer. 
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.