pedelecs
segways
monocycles
tricycles
scooters
patented
bicycles
wheelers
installment
1881
ion
speeds
fleets
prototypes
mph
counted
editions
lithium
motorcycles
battery
wheel
transport
1940s
isolated
tested
200
vehicles
available
limited
electric
engineers
covers
innovative
developed
followed
increasingly
todays
possible
hundreds
urban
open
beginning
popular
road
decade
millions
growing
light
series
powerful
author
lives
century
including
history