Like most electric bikes, the Rad Wagon is also fairly heavy, weighing 72 pounds. The last drawback is that it comes in only one frame size (which I imagine helps to keep costs lower) that fits rider heights between 5 foot 2 inches and 6 foot 2 inches. My 6 foot 4 husband, however, can ride the bike just fine, so there’s some wiggle room to this range.
UPDATE (2019-03-15): I've now got more than 110 miles on the bike and still loving it. The longest ride I did was 28.5 miles and the display was still showing about two bars left on the battery. But the battery gauge is not accurate. Even when it went down to two bars it would also jump back up to 4 bars and stay that way for awhile. So it's really hard to tell how much power you have left. On one ride, after 14 miles the pedal assist stopped working all of a sudden. I stopped and re-seated the cadence sensor and it started working again. Even when PAS didn't work the throttle was still working. It hasn't happened since. There was also a lot of rattling noises which I found was the battery rattling around in the mounting bracket.
Today I’m looking at the Rattan Challenger 350W ebike. It can be found for under $680 at Amazon (after Electrek coupon code 5AIDO2GB) shipped and includes free assembly at a local bike shop. I assembled mine at home however in about 15 minutes with the graciously supplied in box hex tool and wrenches. It is pretty straight forward – the hardest part was bolting the front light on.
Haibike ships the HardNine with 29-inch tires, 180-millimeter hydraulic disc brakes, a 100-millimeter front suspension fork, and a nine-speed Shimano shifting system. The bike’s LCD readout is affixed to the handlebars and displays the current speed, level of charge, remaining range, and current pedal assist mode. The company says the battery can be completely recharged in just four hours, minimizing downtime between rides.
One of the items we demonstrated at the show is the new GMAC motor series. This is a powerful clutchless geared hub motor developed over the past 2 years in partnership with MAC motors, using a custom axle with an integrated splined torque arm. Imagine a MAC motor with perfect frame fit for modern bicycles, zero torque transmission on the dropouts, and phenomenal regenerative braking control.
In China, e-bikes currently come under the same classification as bicycles and hence don't require a driver's license to operate. Previously it was required that users registered their bike in order to be recovered if stolen, although this has recently been abolished. Due to a recent rise in electric-bicycle-related accidents, caused mostly by inexperienced riders who ride on the wrong side of the road, run red lights, don't use headlights at night etc., the Chinese government plans to change the legal status of illegal bicycles so that vehicles with an unladen weight of 20 kg (44 lb) or more and a top speed of 30 km/h (19 mph) or more will require a motorcycle license to operate, while vehicles lighter than 20 kg (44 lb) and slower than 30 km/h can be ridden unlicensed. In the southern Chinese cities of Guangzhou, Dongguan and Shenzhen, e-bikes, like all motorcycles, are banned from certain downtown districts. There are also bans in place in small areas of Shanghai, Hangzhou and Beijing. Bans of "Scooter-Style Electric Bikes" (SSEB) were however cancelled and in Shenzhen e-bikes may be seen on the streets nowadays (2010–11).
"Bicycle" means either of the following: (1) A device having two wheels and having at least one saddle or seat for the use of a rider which is propelled by human power. (2) A device having two or three wheels with fully operable pedals and an electric motor of less than 750 watts (one horsepower), whose maximum speed on a paved level surface, when powered solely by such a motor while ridden, is less than 20 miles per hour.
Can I legally buy/build and ride an ebike that’s faster than 20 mph? Yes you can, but you need to know that the ebike is no longer considered equivalent to a bicycle and is subject to other state vehicular classifications. The definitions for electric bikes spanning 20-30mph, and 1-2 horsepower ranges, will vary from state to state, resulting in a no-man’s-land consensus about limits for motor vehicle definition. The common label for a 20-30mph, 2-wheeled vehicle with active pedals is a Moped. Other MVA labels include motor scooter, motorbike and dirt bike which may have equivalent power and speed performance, but do not have pedals to assist and move the vehicle.
The oldest patent for an electric bike I've been able to find at the US Patent and Trademark Office is this one, by Ogden Bolton, Jr. of Canton Ohio, which was filed in September 1895 and granted three months later. You can see from these original diagrams that it bears an amazingly close resemblance to modern electric bikes. In the general picture on the left, you can see there's a hub motor on the rear wheel (blue), a battery suspended from the frame (red), and a simple handlebar control to make the thing stop and go. In the more detailed cutaway of the hub motor on the right, you can see there's a six-pole magnet in the center (orange) bolted to the frame and an armature (made from coiled wire, yellow) that rotates around it when the current is switched on. It's quite a hefty motor even by modern standards; Ogdon mentions "a heavy current at low voltage—for instance, to carry one hundred amperes at ten volts." So that's 1000 watts, which is about twice the power of a typical modern bike hub motor.
The great majority of modern bicycles have a frame with upright seating that looks much like the first chain-driven bike. These upright bicycles almost always feature the diamond frame, a truss consisting of two triangles: the front triangle and the rear triangle. The front triangle consists of the head tube, top tube, down tube, and seat tube. The head tube contains the headset, the set of bearings that allows the fork to turn smoothly for steering and balance. The top tube connects the head tube to the seat tube at the top, and the down tube connects the head tube to the bottom bracket. The rear triangle consists of the seat tube and paired chain stays and seat stays. The chain stays run parallel to the chain, connecting the bottom bracket to the rear dropout, where the axle for the rear wheel is held. The seat stays connect the top of the seat tube (at or near the same point as the top tube) to the rear fork ends.