As a counterbalance to the cute utilitarian bikes above, the Specialized Turbo Levo FSR Comp is a big, bad, and burly mountain bike. With 27.5-inch wheels, massive 2.8-inch tires, 150mm of travel in the front and 135mm of travel in the rear this bike is made to shred. The Specialized 1.3 Rx Trail-Tuned motor is designed specifically for off-road riding and features a double freehweel design that disengages the gear box at top speed to reduce friction while ripping downhill. The low center of gravity and stout parts make this one a relatively nimble handler that is ready for the rowdiest downhills.
More powerful pedelecs which are not legally classed as bicycles are dubbed S-Pedelecs (short for Schnell-Pedelecs, i.e. Speedy-Pedelecs) in Germany. These have a motor more powerful than 250 watts and less limited, or unlimited, pedal-assist, i.e. the motor does not stop assisting the rider once 25 km/h has been reached. S-Pedelec class e-bikes are therefore usually classified as mopeds or motorcycles rather than as bicycles and therefore may (depending on the jurisdiction) need to be registered and insured, the rider may need some sort of driver's license (either car or motorcycle) and motorcycle helmets may have to be worn. In the United States, many states have adopted S-Pedelecs into the Class 3 category. Class 3 ebikes are limited to <=750 watts of power and 28 mph.
Because e-bikes are capable of greater speeds for longer periods of time than standard bikes, you want extra control. Wider tires provide traction and some bump absorption with little penalty. You also want strong brakes to slow you (and all that extra weight) easily. It's worth looking at the quality of the brakes and investing in bikes with better ones if you can.
Over the course of our testing, our testers universally agreed that the HaiBike XDURO AllMtn 8.0 had the most responsive and robust motor. The system felt almost twitchy, raring to go with a torquey feel that started the moment you pushed on the pedals. It got up to speed quickly and felt like it had the fastest top speed of all the models we tested. The power output was smooth and consistent, and shifting between the system's 5 support settings went off without a hitch. Testers also loved that the power band extended for a moment after you stop pedaling, not quite as long as the Commencal, but enough to still be a benefit on the climbs. The Commencal has a similarly strong motor, but couldn't quite match the torquey feel of the HaiBike or the top speed, although it has an even longer push of the power band when the pedaling stops. Both the Trek and the Specialized motor systems felt slightly less powerful, still offering plenty of pedal-assist support mind you, but that also resulted in the most efficient motors and longer distance ranges than the models with more brute power. Note that our Turbo Levo showed up with a top speed limit of 16mph and not the 20mph. We were very disappointed with 16mph as a max speed. Luckily, we were able to get it adjusted back to 20 and were then quite happy. If you buy a Specialized, make sure it's set to 20mph.
For those looking for a fast, versatile, and highly capable full suspension ride should seriously consider taking the Powerfly 7 FS Plus for a spin. Reason being, not only does the ride host an integrated mountain-specific Bosch motor with a top speed of 20 mph, but a full RockShox suspension setup, mid-fat tires for enhanced stability, and high-end mountain bike components work to elevate your mountain biking experience for the better. From rough to nearly impenetrable terrain the Trek Powerfly could very well be the solution to your desired exploration.
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.