DIY enthusiasts, with tens of thousands of converted bikes using throttle-only, 20+ mph kits, are now officially labeled Moped class. While these bikes handle and pedal-ride just as safely as the class 3 speed pedelecs in many cases, our DIY counterparts will be officially kicked out and left on their own for advocacy and legal acceptance in California. This is a big deal, without a class sticker, any DIY electric bike conversion kit is considered a Moped and not a bicycle.
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.

On the other hand, the battery doesn’t lock into the bike, which means you can’t just leave it on your bike when you park at the bike rack. Anyone could walk by and simply remove your battery. That seems like an oversight to me, though perhaps the designers assumed that such a small battery would just be easy to take with you. And it is. My wife could probably lose this battery in her purse.

The great majority of modern bicycles have a frame with upright seating that looks much like the first chain-driven bike.[7][8][9] 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.
In 5 years of working as a bike messenger in Minneapolis, I've ridden all kinds of bikes, in all kinds of weather. I've ridden walmart mountain bikes, 80's classic steel road bikes, kitted out Treks, pretty much everything EXCEPT for fat tire bikes. Such wide tires always seemed... too much. No need for a bike that only makes itself worthwhile maybe two months out of the year, I thought.
How do the State Laws relate to the 2001 Federal Law? This is a difficult question to answer and know how they apply to you individually. From the Federal Law, one would hope that your purchased ebike is simply classified as a bicycle, with all the rights and privileges allotted to a normal cyclist. However, State Laws are confusing because they may be more restrictive in parts and add other requirements. About 30 U.S. states still have confusing regulations around them. Either the bikes are technically classified as mopeds or motor vehicles, or they have equipment, licensing or registration requirements that cause problems for riders. Thanks to the People-For-Bikes/Bicycle Product Suppliers Association (BPSA) partnership with local advocacy groups, they have been able to make the case for streamlining state regulations so that e-bikes are essentially treated like regular bicycles.4
The word bicycle first appeared in English print in The Daily News in 1868, to describe "Bysicles and trysicles" on the "Champs Elysées and Bois de Boulogne".[11] The word was first used in 1847 in a French publication to describe an unidentified two-wheeled vehicle, possibly a carriage.[11] The design of the bicycle was an advance on the velocipede, although the words were used with some degree of overlap for a time.[11][12]

It is very important that sensors work well and that they are integrated/tuned for good usability. Although ebikes do need some initial mental adjustment from riders, some model do much better then others, e.g. most testers seem to prefer the TDS Impluse over the Stöckli E.T. over the Stromer (which model?) with respect to reactivity. Of course, usability is subjective and some people may prefer one behavior over an other. However, cheap bikes may be just plain bad and this is why test driving is important.

The federal Consumer Product Safety Act defines a "low speed electric bicycle" as a two or three wheeled vehicle with fully operable pedals, a top speed when powered solely by the motor under 20 mph (32 km/h) and an electric motor that produces less than 750 W (1.01 hp). The Act authorizes the Consumer Product Safety Commission to protect people who ride low-speed electric vehicles by issuing necessary safety regulations.[63] The rules for e-bikes on public roads, sidewalks, and pathways are under state jurisdiction, and vary.