My 70s german Hercules "Klapprad" folding bike. with a few minor modifications and upgrades it turned into a very nice little bike. And the doumatic-kickshift is just a great piece of engineering
Sunnywheel Klapprad Bügel 28 cm Stahl schwarz - Internet-Bikes
Vivi 26Inch Electric 500W 48V Foldable Mountain Bike MTB 21 Speed E-Bike with Mechanical Disc Brake
20" E-BIKE PEDELEC 20" DAMEN KLAPPRAD 6 GANG 25 KM/H - 5 POWERMODI | eBay
Klapprad im Test: 28-Zoll-Fahrrad von Bernds verspricht mehr Komfort