I am going to try the 190/55 size tire on the concours because of its claimed better cornering. However I was glancing through the owners manual and of coarse it says only use stock tires because different size tires rotate at different rpm's and can confuse the ABS/K-Tract system. Has anyone tried it and have good luck? I'm thinking its such a small difference it won't matter but just thought I would through it out there.