Tire size on stock Z1R wheel?

I just picked up a used GS1100 alum. swing arm for my 78 Z1R. Now that I have a wider/longer arm how much tire can I safely get on the stock 18" Z1R wheel? maybe a 150? Or should I be looking for different wheel?

here we go again...good luck...oh you'll get answers:laugh:

Yes. after 130, profile of tire results in less ground patch. G

I'm relatively sure the Z1R uses a 2.5" wide wheel which was pretty common at the time. You can look at the tire manufacturers data on each tire and they normally specify what size wheel is suited to a certain width tire. 130 would be pushing it as far as practical I would imagine. I do the 120/90 on 2.5" wheels and even that is too wide for the wheel in my opinion and makes crowning of the tire more than desirable.

How about my situation?

I'm going to be putting an 18" Z1R front wheel on my kz650C2.
Stock Z1R front tire is a 110/90-18 I believe, compared to a 100/90-19 stock kz650 tire.
On the rear I was contimplating going back to 120 width (stock kz650 size) from my current 130 rear, but having a wider front (110) I wondering if I should continue with a 130 rear.

Thanks for the info I got a 130 on it now, it damn near rubs the stock arm. The GS arm will take a much bigger tire but with a 2.5" rim I'm maxed. Does any one know of a similar style KZ rear wheel that might be at least 3"+ wide? Maybe a later model KZ or somthing off a MKII or LTD. I don't want a modern sport bike looking 3 spoke.

Z1, Have heard of having stock mags being cut and rewelded to diffrent width/diameters. (am guessing you have mags) spokes are easy, just lace a wider hoop. Luck G

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Mark