Wire Wheels From 78 KZ650 on a cast wheel 79 KZ650SR. Anybody ever done it?

I like wire wheels. I don't care about the loss of the rear disc brake. I also don't care about the loss of the 16 inch rear wheel.

Anyone ever done it, or know enough about the two bikes to suggest how to do it?

Thanks and happy Sunday.

I'm just guessing here, but my guess is that the front wheel from a KZ650B would be a direct swap. 
The rear wheel would be harder.  My guess is the KZ1000 spoke rear wheel would not be a direct fit, as I think the hub and sprocket carrier (and probably axle) are larger. But if did the work to adapted it you could keep the rear disk. 
Otherwise you'd need to convert your bike to use a KZ650B drum brake setup.  If you managed to find a junk bike and could get the whole rear end setup that might work. 
You'd need the rear wheel, swingarm, brake lever and pivot, brake rod, and every other piece associated with the swingarm and rear brake.  
I'm still guessing here, but there is a good chance the brake level pivot bushing is in the same place on the B and SR frames.  I mean, why change things around that much?  So there is a good chance the 650B brake lever and pivot would bolt on, and the swingarm should bolt on, and then you're set.  Maybe? 

Here are photos from auctions for an SR and B frames. The brake level busing looks to be in the same place.
 

Never done it but there is no issue in doing it. You may have to change the gearing front and back as the sprockets are different. I believe the SR uses a 630 chain which is overkill. The rear tire on a 18" wire rim should not be a issue as far as the OD.

19" front wheel on both so direct swap with no speedo error.
 

Thanks to everybody here, last summer I added a front disc to my KZ650B milk crate bike. So that would be an easy swap I think.

Did the mighty Kaw ever offer a wheel/hub/ in 18 with a rear disc? That would be very very cool if they did.

Before someone jumps all over me this is when the bike was still single disc.



 

I went the other direction. My wire wheels were due for a rebuild and I suspected they were contributed to a loose feeling at high speeds so I decided to clean up and install some alloy wheels I got from one of our members. I had already installed a 98 KZP swing arm, 1 1/2" longer but the 18" tire was hitting the fender on large bumps so I had to add a fender extension. to move it back 2" but my shocks were 13" not 14" like stock so it was still close. With the 16" rear wheel I can still use a 130/90 tire and the wheel is wider so the contact patch is wider. With the longer swing arm the bike is more stable at a ton and the 16 slowed the steering a bit adding to high speed stability. Add a fork brace and some gussets the bike is solid at speed. Next will be some fork emulators and the front end should be more stable too. I've always liked the rear drum brake because it isn't affected by rain where the front disks have to spin a few turns to dry out. I switched the shocks to 14" so the bike isn't such a "Low rider" too. It felt funny in the turns so it's all good now. 
The problem with changing from stock you change one thing it affects another. KZP swing arm, longer axle and spacers, swing arm pivot had to be modified too, shocks changed, sprocket changed to smaller one and so on. Would I do it again? Yes but I kept the stock parts, didn't hack the frame so I can go back anytime I want. 
BTW I installed late model front rotors replacing the heavy solid disks I had before. 
Before the wreck I had Lester's, these I like better. 
Steve

 

To answer your question about any 18inch spoke wheel with disk brake, yes the 76 and 77 kz750 twin B models did have such. I think there were like wheels on the kz1000 A models for 77 78 79 maybe more.

Other 16 inch rear wheel with spokes would include the 81 and 82 650 H models. The do not have a disk, rather drum brakes.

adding to gd4now's reply. the KZ1000M CSR had wire spoke wheels and triple disks: dual disk at the Fr & Rr disk.
48-spoke aluminum rims. same rims as the 650-CSR. There was a 750-CSR w drum brake but I think it had 40-spoke steel rims

The 1000M CSR has a bigger axle: 18mm & the diagrams indicate the length is 300mm which is about the same as my 650-csr & SR, maybe slightly longer. the axle length isn't listed for my csr and I never measured it.