Although the founder Thomas Humber left the business in 1892 his successors, Harry Lawson and an American Edward Pennington continued the name. Lawson brought with him the rights to his innovative three-wheeler, and Pennington owned a number of important patents. By 1903 the priority for the Humber factories was car production, with motorcycle and bicycle production as a sideline. Success with one of Pennington's 340 cc two-speed V twin engined Humbers in the first ever Isle of Man Junior TT in 1911 boosted the motorcycle sales.
Early Humber motorcycles were built under licence to Phelon & Moore with a single-cylinder P&M engine and two-speed chaindrive transmission. Disputes over royalty payments and P&M's desire to make their own motorcycles led to this licence being terminated in 1905, so later models had Humber 496 cc, 596 cc and 746 cc engines.
Humber was taken over in 1930 by the Rootes Group, who went on to make several very successful cars under the Humber name.