will a 190 50 17 fit on my 99 900rr it came with a 180 55 17

 

Yes, if it's at least a5.5 inch wide wheel but you'll lose steering quickness by doing it. You don't really gain any beneficial tire width anyway because of the wider tire being jammed onto the narrow wheel(190 is usually on a 6.0). It's pretty close to the same width as the 180 once it's on the 5.5inch wheel but it has a shorter profile which is going to slow getting onto the side of the tire when turning. Basically, I'd stick with the stock size and just put some sticky rubber on there if you like turning. However, the shorter profile is good for drag racing since when you let the air down you have a fairly flat wide surface.

In short(if wheel widths are as mentioned above):
180 = good for corner carving
190 = good for drag racing
Hopefullythat's the info you're looking for.

 

excelent thanks for the info