Developments in electric scooters stalled for the next 20 or so years after a Long-Island based company released the Autoped, a competent gas-fueled scooter that saw many sales in the US and Germany. The development of new more efficient gas-powered engines saw many companies manufacture gas-powered scooters. Unfortunately, these gas-powered scooters were often seen as low class and it took a few decades for people to change their minds on the product.
http://www.dbaoescooter.com/old-electric-scooter/