Indian - world renowned American motorcycles built first by George Hendee and Oscar Hedstrom. The company had a really stormy history, the brand name was sold more than once
ItalJet - small capacity bikes built in Italy, nowadays they race in the 125 cc class of the WMC
Ideal Jawa - motorcycles built in India 1961
IKH - Russian bikes
Invincible - Australian motorbikes built in the 20s
Imperial - motorcycles built in America by American Cycle Manufacturing Co.
Izh/Planata - Russian motorcycles built in the 30s
Indian Enfield - a chapter of the Indian’s history, were sold in 1959
Industrial - American motorcycles built in 1903
Irbit - Another name for the Russian-built Ural
Island Hopper - American motorized bicycle manufacturer.
Italemmezeta - motorcycles built in Italy
Italvel - electric motorcycles built in Italy
Iver-Johnson - American built motorcycles in 1907-1915
IWL - Scooters built in Germany, by Industrie Werk Ludwigsfelde
Izh - motorcycles built in Iran by The Izhroosta Co.
Imperia - German motorcycles built in the 20s