back tire

Running a 120 on the back of my 1000 its not very wide at all.What is the biggest tire I can use without extending the arm..

i'll be watching this thread i have a 130 on mine. make sure to put your bike in your signature go to "my profile" in the forum it will help people answer your questions. Also if you feel comfortable slap in your hometown and state and someone on the forum may want to hook up.

I think 130 is as big as you can go.

Running a 140/90-18 on my 76 900. stock swingarm but no chain guard. about 6mm between tire and swingarm each side. May be more if you use 140/80-18.

140 is the biggest that will fit and may need some massaging to make work while a 130 will fit without any issues. Naked eye won't be able to tell difference between the two, so I would go with the 130 for ease of fit and be happy with it.

Even a 120/90 will generally rub the chain guard. (Tire sizes vary greatly between manufacturers). 120 is the widest tire to run on a stock 2.15" wide wheel. Any bigger than that you're not getting the correct tire profile. These old Kawasaki's were not made for 6" wide tires on a 2.15" wheel. The new motorcycles are another story as they have wider wheels to fit wider tires.