Photo: Left: The hub motor of an electric bike. Right: If you took off the casing, this is the kind of thing you'd see. It's a simple brushless motor from a PC cooling fan, but it works in broadly the same way as a bike's hub motor. There's a static part made up of four electromagnet coils (left) and a rotating part (right) made from a permanent magnet (the gray ring) that clips onto it. When the coils are energized in sequence, they generate a magnetic field that makes the permanent magnet and fan spin around. At a glance, a hub motor looks much like an ordinary bicycle hub, but look closer and you'll find it's a lot more bulky.
We rode the Vado through the gauntlet, including some of the steepest hills in Palo Alto, and it easily handled everything we threw at it, maintaining a steady 20 miles per hour even on the most daunting of ascents. The bike also handles well on downhills and is both nimble and quick on city streets and paved trails. It’s even comfortable to ride for extended distances, which is vitally important for any bike built for urban settings.
Class 1 makes great inroads to establish set boundaries for off road/natural surface trail access for eMountain bikes. There is fierce resistance from some mountain biking purists to allow ebikes on trails. BPSA and IMBA have done good work to justify the impact of class 1 ebikes on natural surface trails, and eliminate the wear-n-tear argument, though IMBA members are not 100% on board.
Both bikes have passable cadence sensor pedal assist that kicks in a little late and lets go a little early. Torque sensors are too expensive for this price level so you are just not going to get the same responsiveness as a bike store e-bike. Rattan has 5 levels of pedal assist while the Ancheer has 3. Over long periods of pedaling the PAS evens out or you can just use the throttle.
Ebike definition in Colorado follows the HR 727 National Law: Template:Convert e-power and Template:Convert max, 2 or 3 wheels, pedals that work. Legal low powered Ebikes are allowed on roads and bike lanes unless the city or county has passed laws to the contrary (Boulder city bans ebikes over 400W from bike lanes and all ebikes from bike paths) -none -(except Boulder city) have to date. Bicycles and Ebikes are disallowed on certain high speed highways and all Interstates unless signed as "Allowed" in certain rural Interstate stretches where the Interstate is the ONLY means of travel.  Unless the locality has specifically passed laws making ebikes illegal on sidewalks or trails, Ebikes are legal. However most business and shopping districts do not allow riding bikes or ebikes on sidewalks. Boulder and a few other cities specifically dis-allow ebikes on their trail systems through legal statute.
DON'T BUY THIS BIKE!!!!! Worst customer service ever!!! I bought this bike for my 18 year old son to commute to school. It worked well for the first 2 months but the battery is cheap and stated to wear out. I tried going on the website, but they battery shows as out of stock, and has been for 3 months now. I left 5 emails with customer service, never got a reply. Also there is no number listed on their website to even speak to a real person. Now I have a worthless 5 month old bike..... horrible this company should be ashamed.
There are many possible types of electric motorized bicycles with several technologies available, varying in cost and complexity; direct-drive and geared motor units are both used. An electric power-assist system may be added to almost any pedal cycle using chain drive, belt drive, hub motors or friction drive. The power levels of motors used are influenced by available legal categories and are often limited to under 750 watts.
This article did a good job of trying to justify the assist speed limits but fell short of detailing how that can ever be effectively enforced. In reality the only enforcement that is going to work is applied speed limits to use of bikes and ebikes. For example, it makes sense that a bike lane on a street that the speed limit of vehicles is the speed limit of the bikes/ebikes. On sidewalks and shared pedestrian paths the speed limit probably does need to be in the 15-20mph range to match traditional bikes speeds on those paths.
Perhaps the cleverest thing of all about the Electric Brompton is that despite all the extra stuff, it folds up exactly the same as the non-powered variety. It's so simple, and unlike certain folding bikes we could mention, what you're left with is a genuinely small thing, rather than something that's about the size of a bike with the front wheel taken off.