Changing tire size on a stock rim?

[johnmichael]

I was wondering if it is ok to go up, or down a size on your rear tire, with a stock rim? The bike is a 1125r. I would like to replace the stock 180 for a 190. I also have an 929RR, I would like to go down a size on the sock 190 and replace it with a 180. The 929 is in Japan with tight windy roads, 1125r is in the US with allot more straightaways. I cant swap bikes either because the 1125 is not legal in Japan. Thanks in advance for any advise/constructive criticism[smirk]

 

[delta one]

you can go up but the point is nill. the width will be about the same. wide tire in a narrow rim still has a narrow profile but it will be a bit taller and it can feel strange as you lean it over. it wont be a consistent height change, it will look more like the tire is coming to a point instead of gentile curve.

same deal with going smaller only backwards. the tire will be more flat and shorter in the center if you stretch it over a too wide rim.

for best handling either go new wheel/rim or stick with stock.