This from Castrol:

From an article in Motorcyclist Magazine: "Riders who warm up their motorcycles for extended periods risk engine damage."

From David Jilbert, head of Castrol's English motorcycle research department: "The anti-wear components of engine oil do not work properly until the oil is heated to 140 degrees Fahrenheit to 158 degrees Fahrenheit." He went on to say that to warm up the engine and oil properly, the bike must be ridden.