Will a 180 fit on a...

[PJ]

5.75" rim? 6" rim? At what point are you forced to run a 190?

[Woofentino Pugrossi]

Should fit on a 6" fine.

[Super Dave]

+1

[PJ]

Thanks guys!

[IBFrank]

But you will need to change your gearing now too!! Tell em Special Dave

[PJ]

But you will need to change your gearing now too!! Tell em Special Dave

Huh? That's what I was hoping to avoid, changing gearing and suspension settings. I'm using a 180 rear now. Just going to a slightly wider rim. Why would using the same profile tire on a 1/4" wider rim change gearing?

[spyderchick]

Huh? That's what I was hoping to avoid, changing gearing and suspension settings. I'm using a 180 rear now. Just going to a slightly wider rim. Why would using the same profile tire on a 1/4" wider rim change gearing?

I think he's funnin' at Dave. 

[Gixxerblade]

Thanks for the answer! I got got some Marchesini's and was worried about that too. Except I think the 04-05 Gixxer rim is 5.5, right?

[GSXR RACER MIKE]

Huh? That's what I was hoping to avoid, changing gearing and suspension settings. I'm using a 180 rear now. Just going to a slightly wider rim. Why would using the same profile tire on a 1/4" wider rim change gearing?

Because it changes the outside diameter of the tire by allowing the tire to expand to the sides a little bit more therefore reducing the overall height of the tire, at the opposite extreme a narrower rim would cause the same tire to be taller (this is all using the exact same tire). By changing the height of the tire you effectively change the gearing as well, remember that tire has to turn alot of times to go a certain distance so even a minor change can sometimes have suprising results. The other thing it can do is throw off the geometry of the bikes set-up since it changes ride height a bit.

Either of these things may not be substaintial enough to cause a problem in handling, turning in, or holding a line - but it potentially could so I would test it to see if it still handles the same or not.

[Super Dave]

I think what Otis is getting as is that a 180 and a 190 won't necessarily have the same circumfirance, period.  That will change the chassis geometry and the final gearing. 

If they are both 50 aspect ratio tires, the heights are different, period.  You've got to calculate it first, then contact the manufacturer too 'cause 180/50ZR17 is just a size...the real tread could be 183 with the aspect ratio really being 48%, as an example.