Kz750 rear wheel question

My 82 750ltd has a 16x3 rear on it now and I'd like to change to an 18 for more tire options (not many trail/adventure tires for a 16).

The only rims I'm able to find right now are 2.15 wide from a GPZ550. Am I correct that the police model was the only one with a wider rim at 2.5? And are these rims a direct swap or do I need some other components to make it all work?

If I can get decent tires for with the 2.15 wide rim then I'll just get that one, but I suppose 120 is the widest I could go, and I could probably get a 130 on the 2.5 rim?

Apologies, I'm sure this has been asked before, but I've been doing a lot of reading and still lack a lot of knowledge about this.

What year is the 550? From the diagrams at Partzilla the 550-D1 has the same axle & the sprocket carrier coupling assy is the same plus some of the other stuff is the same as well, so there's a good chance it will work. You can compare the stuff yourself to verify. This is what I did before getting 550 cast alloy wheels for my 650-CSR.

As for the a 1000P police motorcycle, the rear axle is larger in diameter, so the components will be different as a result. I have no idea if the swap can be done.

martin_csr wrote: What year is the 550?

It's from an 82 Gpz 550h

Operatic wrote: My 82 750ltd has a 16x3 rear on it now and I'd like to change to an 18 for more tire options (not many trail/adventure tires for a 16).

The only rims I'm able to find right now are 2.15 wide from a GPZ550. Am I correct that the police model was the only one with a wider rim at 2.5? And are these rims a direct swap or do I need some other components to make it all work?

If I can get decent tires for with the 2.15 wide rim then I'll just get that one, but I suppose 120 is the widest I could go, and I could probably get a 130 on the 2.5 rim?

Apologies, I'm sure this has been asked before, but I've been doing a lot of reading and still lack a lot of knowledge about this.

Correct. A 120 tire on a 2.15 rim is about as wide as makes sense. For years I ran 130 tires on a 2.15 rim, but eventually I discovered that the narrow rim distorted the tire and left no more tread touching the pavement than that of a 120 tire. The 130 tire is rather difficult to mount on a 2.15 rim and offers no advantages over a 120 tire. Ed