In a parallel hybrid motorized bicycle, such as the aforementioned 1897 invention by Hosea W. Libbey, human and motor inputs are mechanically coupled either in the bottom bracket, the rear wheel, or the front wheel, whereas in a (mechanical) series hybrid cycle, the human and motor inputs are coupled through differential gearing. In an (electronic) series hybrid cycle, human power is converted into electricity and is fed directly into the motor and mostly additional electricity is supplied from a battery.
E-bikes are classed according to the power that their electric motor can deliver and the control system, i.e., when and how the power from the motor is applied. Also the classification of e-bikes is complicated as much of the definition is due to legal reasons of what constitutes a bicycle and what constitutes a moped or motorcycle. As such, the classification of these e-bikes varies greatly across countries and local jurisdictions.
11. Disputes: THIS SWEEPSTAKES IS GOVERNED BY THE LAWS OF United States AND PA, WITHOUT RESPECT TO CONFLICT OF LAW DOCTRINES. As a condition of participating in this Sweepstakes, participant agrees that any and all disputes which cannot be resolved between the parties, and causes of action arising out of or connected with this Sweepstakes, shall be resolved individually, without resort to any form of class action, exclusively before a court located in PA having jurisdiction. Further, in any such dispute, under no circumstances will participant be permitted to obtain awards for, and hereby waives all rights to claim punitive, incidental, or consequential damages, including reasonable attorneys' fees, other than participant's actual out-of-pocket expenses (i.e. costs associated with entering this Sweepstakes), and participant further waives all rights to have damages multiplied or increased.
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.