[awjr]

No idea why they are single speed. Have these people not heard of hills ;)

A local company uses eBullit, but can only get about 4 hours out of the 500w battery due to hills.

I could see an advantage in offering a 1000w light-moped version however these would be illegal on cycle paths.

[mxfh]

They are purpose build for door to door postal letter delivery, sturdiness and low maintenance. Top speed is quite irrelevant and electric motor assisted operation is how is compensated for the weight and terrain. They are legal on bike paths since they are throttled to 25km/h so they still classify as normal bikes.

Unrelated, they do manual powered boats too: http://www.dpdhl.com/de/presse/pressemitteilungen/2017/start...

[Gravityloss]

German post office delivery river boat. How cool is that? I could see this becoming a "must have" thing in the San Francisco bay. ;)

[beamatronic]

You'd have people living in them to save on rent. And they'd make them self-pilot around the Bay to avoid the whole marina-liveaboard limitation issue.

[usrusr]

They are single speed because with a load like that nobody wants to go anywhere close to the 25 km/h of legal motor assist.

I work next to a depot of those so I occasionally share a bike path with them while they are in cruise mode (moving to their delivery area, as opposed to going mailbox-to-mailbox). They go a brisk pace considering the load, but certainly not much faster than the speed required for comfortable balancing. This is no bike messenger from hell tool designed to win alleycat races (though that wouldn't exactly be the home turf of 2x11 componentry either).

Between 250W of assist for hops and acceleration and a very narrow speed band to optimize the gearing ratio for, you really don't need a multispeed transmission.

[buro9]

It's a pedal assist variety of electric motor that provides up to 45km/h on the flat and 32km/h on mountains depending on the motor chosen.

http://www.go-swissdrive.com/en/the-go-swissdrive-system/mot...

Singlespeed, I assume you just got this from the drivetrain type which doesn't really relate to hub-geared electric motors.

[Xylakant]

The mail delivered by these bikes is stored in pickup places along the route and at least occasionally I see replacement batteries picked up with the mail. So there's limited need for a larger capacity.

[foepys]

> No idea why they are single speed. Have these people not heard of hills ;)

I think the idea here is that the electric motor will help in those cases.

[driverdan]

I have an electric bike with seven gears. I almost never shift because it's unnecessary. I can climb steep hills without shifting if I use the electric throttle.

Just to clarify your statement about batteries, you seem to have mistaken the motor rating for battery rating. Motors are rated in watts, batteries are rated in amp hours.

[photojosh]

Same. Regularly go up a 10% grade.

Except for when I'm towing kids in a trailer. 70kg extra means that the motor will drop out when speed drops below 5-6 km/h, because it's a hub motor. 250W isn't quite enough in that situation. Am contemplating upgrading to a longtail now that the kids are older, and will definitely get a mid-drive if I do.