Humber Flex LT PlusHumber Flex LT Plus The Flex LT Plus adds enhanced features to the lighter Flex LT platform, giving riders a practical and easy to live with electric cargo option for family, commuting and utility riding. Humber electric cargo bikes combine Danish design, practical everyday transport and reliable Promovec electric assist systems. Built for family journeys, business use and day to day utility, the range focuses on comfort, stability and useful cargo