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November 2018

E–bikes and e-scooters have arrived. Now what?

by John Allen

Improvements in batteries and electric motors in recent years have allowed higher power output with lighter weight and bulk, finally making it practical to power vehicles electrically. In one very important sense, this is a blessing: it reduces ground-level air pollution. Depending on the source of electric power to charge the batteries it also reduces regional air pollution and emission of greenhouse gases.


An electrically-assisted bicycle can now take the place of a gasoline-powered moped – and can be stored indoors without stinking up the place. Fire hazard? There is no problem with gasoline, though lithium-ion batteries have at times been known to cook themselves.

Electrically-assisted bicycles are of many kinds and have many uses. I know of at least one baby-boomer CRW member who is riding one to keep up with stronger riders, and another, just to keep riding. A light whining noise emanating from pedicabs in Provincetown reveals their little secret, see Any bicycle or tricycle which carries passengers or cargo is more practical with electrical assist. None of these are speedsters: the assist serves mostly to make their performance comparable with that of conventional bicycles.

Speed, however, can be an issue – the main issue – when a conventional bicycle acquires a motor. A cyclist’s skill and fitness generally develop together: the fast-but-clueless cyclist is rare. This limitation falls away with electrical assist.

The bicycle industry is pushing for laws establishing three categories of e-bikes:

“Pedalec”, pedal assist (maximum speed at which power is added, 20 mph);
“Throttle”, throttle-controlled, 20 mph;
“Speed Pedalec”, pedal assist, 28 mph.

Different rules would apply as to where each of these are legal. Any of them, increase the hazard for people with deficient bike-handling and traffic skills.

What answers are there to these problems? The only ones I can see are experience, education and enforcement. When I visited Taiwan a number of years ago, the most common vehicles were motor scooters. Traffic was orderly and I didn’t see any crashes in the week I was there. The speed pedalec ‘s performance is similar to that of a motor scooter. They can both be operated according to the standard rules of the road, but the regulatory and law-enforcement climate in the USA is anarchic. Here in Massachusetts, all electrically-assisted bicycles and tricycles are lumped into the same category as gasoline-powered motor scooters – see this: , but laws requiring registration and licensing are not enforced. I contend that they are probably not warranted for a 20 mph pedelec, but they probably are for a speed pedalec.

What about use on paths and off road? E-bikes are quiet and non-polluting, but their speed makes problems more likely. Mountain bikers have struggled for decades for trail access, and are rightly concerned about losing it. Shared-use paths, as well as trails open to mountain bikers, prohibit all motorized vehicles. How much are these rules likely to bend in the interest of allowing pedal assist to people who need it just to keep going as they (we!) age?

Standup scooters

The performance of e-bikes falls somewhere between that of bicycles and mopeds, both of which are recognized road vehicles. Electrically-powered standup scooters , on the other hand, raise additional issues.

At various dates in 2018, companies Bird, Lime, Skip and Spin have released dockless rental electrically-powered scooters into a number of US cities -- sometimes with approval from the city government, sometimes without. These scooters represent more or less a third wave in the advent of shared two-wheel personal transportation. First came docking bike share, then dockless bike share, raising an issue of “bike litter”. Now we also are seeing dockless rental electrically-powered stand-up scooters.

A bicycle's design reflects a compromise between the risk of a stopping-type crash and the bicycle's practicality and convenience. Avoiding the risk of a "header" or "endo" with a conventional bicycle, electrified or not, is largely a function of cyclist skill in avoiding hazards and in using the brakes. All in all, the hazards resulting from bicycle geometry are tolerated, and studies point out that bicyclists, on average, live longer than other people. The benefits of exercise outweigh the risk of an injury or fatality.

A stand-up scooter has a much worse problem with stability than a modern bicycle. The line from the center of mass to the front wheel contact patch is nearly as vertical as on an 1880s high-wheeler bicycle, only the front wheel is much smaller and pothole-prone. Also there is little benefit of exercise.

Blogger Bike Snob has written about these scooters in Outside magazine, . He is generally pleased with them as an additional transportation option but he gives a paragraph to safety issues: At one point, I rode down the gentle slope of SE Sandy Boulevard [Portland, Oregon] in the bike lane when a driver crossed my path. On a bike, I would have feathered the brakes and thought little of it, but on the scooter I immediately locked up the wheel, causing it to fishtail. I put a foot down and recovered quickly because I’m awesome, but it was a good lesson in how much faster you’ll hit the limits of a scooter than those of a bicycle. There’s also the fact that a bike is better suited to carrying heavy loads. You’d have a much easier time making a grocery run on a bike than on a scooter. And perhaps most crucially, due to the geometry of the scooters, it’s very difficult to ride them one-handed. Forget glancing at your phone or adjusting your bag; even hand signals are pretty much out of the question.

Is this acceptable? There is no saddle, and so, no point of reference for upper-body position. Forward/rearward rocking of the rider due to pavement irregularities, braking etc. will abruptly steer the scooter out from under the rider. Hanging baggage over the handlebar doesn't help with steering stability either, and these scooters offer no other option for baggage other than a backpack. A Washington Post article: describes some of the issues. People with little experience are riding these scooters on sidewalks, annoying pedestrians, and getting into crashes which most bicyclists would avoid, at an alarming rate.

Steven Goodridge, CyclingSavvy instructor and engineer, has done some experimentation on scooter handling, and describes it at length in a comment on a Facebook post, . Goodridge agrees with Bike Snob’s observations about stability. He finds that front-wheel braking of the Bird scooter he tested is limited to prevent pitchover -- though of course, only when due to braking, not surface hazards or abrupt steering. Rear-wheel braking appears to be automatically modulated in some way but can still cause fishtailing. Maximum braking is barely within the limit possible on a bicycle which has only a rear-wheel brake, typically also the legal requirement: 15 feet from 15 mph.

Goodridge also finds that motor power of the Lime scooter is "insufficient for even the slightest couldn’t handle a number of the short hills at more than walking speed. Acceleration into traffic is slower than manual kicking." Bicycle speed is less than that of most motor vehicles, but a bicyclist is able to sprint rather smartly from a stop.

Signaling turns is required by law. Any vehicle which travels on streets should allow the full range of control options required under the law, including signaling. But, with these scooters, not only is hand signaling impractical: the very small height and width of the rear-wheel and fender assembly make turn signal lights impractical.

The e-bike phenomenon, and much more acutely, the electrical scooter phenomenon, are examples of technology and commercial interests getting ahead of government management and regulation, a phenomenon which is occurring on many different fronts at the time of this writing.

I think that in the long run, the e-bike situation will sort itself out, but the deficiencies of electric standup scooters will lead to legal challenges and limit the willingness of entrepreneurs to offer them. Time will tell.

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