Rear Drum to Disc, can it be done?

I have a 76 650b and a 77 650 c. The C has rear disc, and dual in the front, but they are mounted to mags. I would rather use my spokes, as they look better for a cafe racer style bike(which i am building) The front wheel seems ok, I have mounts on my forks on both sides and the wheel looks like it will take the second rotor. My question is: is it possible to remove the rear drum and replace it with a rotor? I want to mount these wheels on my C frame which is all setup for the rear disc, otherwise, any suggestions on powder coat colors for the mags?

No they're entirely different. You'll need a new wheel.
KZCSI

get a set of wire wheels for a kz1000 shouldnt take much to mountB) goodluck,happy wenching!

wireman wrote:

get a set of wire wheels for a kz1000 shouldnt take much to mountB) goodluck,happy wenching!

Just keep in mind that a KZ1000 uses a larger rear axle diameter than the KZ650, so you will need the axle, spacers, caliper hanger, etc. Or drill out your caliper hanger, axle adjusters, and swingarm to the larger axle size.
Or you could make an adapter to mount the KZ650 axle in the KZ1000 wheel, a tube with the ID of the 650 axle and the OD of the 1000 axle.

Any of the 650s use a spoke wheel with disk rear brake? If so, then that would be the easiest way to do it.

i dont remember ever seeing a 650 with a stock disc brake wire wheel .i know the 1000 front wheel will bolt on 650 forks,he has a disk brake mag wheel on the rear are you sure the axle diameter is differant?ive put 1000 swingarms on drum brake 650s to convert them to diskbrakes with no problemB) goodluck,happy wrenching!

Yep, I'm positive
The KZ1000 uses the same diameter rear axle as the KZ750 twin (many chassis parts are the same between the two) and the 650 uses a smaller axle. Using the 650 axle in the 1000 swingarm allows the axle to get cocked vertically, (one side higher than the other) because the axle slots are larger on the 1000 to allow for the larger diameter. When I got my current 750 twin daily driver the sprocket teeth were like pyramids, they were worn to a point because it had a 650 rear wheel and axle in a 750 swingarm. With no centerstand someone had adjusted the chain while it was on the sidestand and appaently did not make sure the axle was either all the way up or all the way down before tightening the axle.

You can go to buykawasaki.com and compare wheel bearings for the two models in question to verify that the axles are different diameters, and I think there is a wheel bearing list in the Filebase that you can check also.

Kawasaki used thick axles in the earlier models then went to thinner axles later on. I'm not sure but the 81 and later 1000s might have the same axle diameter as the KZ650. I know the 82 750 twin has a smaller axle than the 80 750 twin, even the 750 fours use a smaller axle than the 76-80 750 twins or the 1000s.

Post edited by: steell, at: 2006/01/30 10:28

I would also like to point out that the rear master cylinder needs to be mounted. The mount is usually welded to the frame and doubles as a support for the battery box I think or even a motor mount. You will either have to fab one or cut one from a donor bike and weld it on your frame. Once you have the mount welded on and the rear master cylinder bolted to it, you may now notice that your battery which probably came out from that side, doesn't come out any longer as the master cylinder is in the way. You will have to get a battery box from a rear disk 650 and pull the battery out from the top; or at least that is the way it works on the larger bikes.

i think he said this bike is allready set up for rear disc,he just wants to change the wheelsB)

You are right. I misread the original post and thought he had a B and wanted to mount the C stuff... sorry!

Thanks guys. I must say yes I am sadly dissapointed. To clear up a few things. My B did in fact come original with a front single disc on spoke wheels, someone had doubted that, and yes I guess I will have to use the mag wheels..... Any ideas or thoughts or better yet pictures on a powder coat color. I like what guys are doing lately, a flat textured grey or creme color. looks pretty cool.

i were referring to a rear wire wheel with disc brake on a 650,my bad!:whistle: