HI,
You need to get the rear wheel nut socket. I'd highly recommend the www.speedymoto.com
http://www.speedymoto.com/Merchant2/merchant.mvc?Screen=PROD&Product_Code=04-0203&Category_Code=SMT
A standard socket in this size is problematic as it might slip off because of torques involved. You also need a good torque wrench as well to do the job properly as the nut needs to be torqued to specs when remounting the wheel.
good luck
Chris
I just got my new tire delivered. I want to take the back tire off and have the dealer switched the old for the new one. I heard that for the 1198 and 848 you need a special tool. Is it true for the hypermotard too?