Oversized Tyres?

An interesting question. What would be the benefit of doing it?

 

I will be interested in the responses you get.

 

I used to race a cbr600 honda in the steel framed series a while back (12 yrs ago ) - and we regularly used to fit 180 rear's onto the wheel rim designed for 160's ,I think it was a 5 inch rim, anyway , the point is , I was advised at the time that this would give a greater contact patch mid corner but would compromise straight line stability , I personally found that it worked well & got some of my best laps on a bigger rear , plus at that time there was a better choice of 180 rear's than there were 160's in the club racing world because R1's ,R6's & gixxer's were everywhere and the paddock tyre suppliers had the best selection in those sizes .
Having said all of that , I've looked at the rear tyre on my america & its quite a high profile tyre wall that kind of bulges out a bit , and if you were going to fit a 180 on in place of the 170 that tyre wall may bulge out even more , on the sportsbikes the profile is quite low and as a result the tyre wall angles a bit more , so I think the only thing you could do is try one on & see what it looked like , there's plenty of room for clearance so that won't be an issue . The two thing's to consider are that it might invalidate your insurance if it ever came to light after an incident , although you'd be a bit unlucky if it did I imagine & the other is that if fitting an oversized tyre could compromise straight line stability in any way , then on this type of bike it would be most disadvantageous .