I have the Austone also. It's about an inch taller than a stock tire. For those of us who do a lot of cross country riding it's like having overdrive. The engine turns only about 3,000 rpm at 75 mph. As great as that is for us, it may feel like the gearing is too tall with your sidecar. You may be more interested in a 195/55R16 which I can't speak for because I've never run that size. The Austone is 175/80R16. A tire very similar to that in size is 185/75R16. The 195/55R16 also comes in the run on flat with very stiff sidewalls. Folks will be along any minute now to give you some insight based on experience on these tires. What ever your choice of tire, you are going to love your bike, the ride and the adventures it takes you on.