Rear caliper rubs on rear disc

First of all, thank you all for your knowledge. I have been searching previous posts for the past month and been able to answer almost all my questions during my recent 1977 KZ1000 restoration. Thanks for all the help.

I have not been able to figure out my rear brake. I have a 1977KZ1000A which I bought a month ago. It is in great shape, mostly stock, except it has LTD pipes and wheels (16in rear). When I took apart the back axle to check the bearings and brakes I noticed an extra washer between the spacer and the brake caliper. When I tried to reassemble without the washer the caliper rubs the disc on the outboard side. It does not rub with the washer in place but it is a horrible struggle to spread the bars enough get everything in place and get the axle through.

I have been told the best way to convert to mag wheels is take the wheel, disc and caliper together from the donor bike. I don't think the previous owner did that. I also know the A and the LTD had different rear calipers because they use different brake pads.

So, my questions.
How can I tell which rear caliper is on my bike?
What combination of disc and caliper would cause rubbing on the outboard side?
What should I replace so I don't have to cram the extra washer between the spacer and the caliper? Does anyone have both discs on hand so they can measure which one sits further out from the rim?

I am hoping to have this project finished to enjoy over thanksgiving.

Thanks for the help!

The calipers are different from year to year. The place where you have to install the washer on the caliper comes in different thickness. Is your caliper cast iron or aluminum ?

Welcome to the forum.

Don't know if you are just trying to get the washer in, but might try putting everything on the axle and rim and sliding it thru the back of the swingarm with the bolt on ends of the swingarm removed.

The 1977/1978 KZ1000B models (LTD's) use a rear caliper that looks like a front caliper with a circular brake pad.

The 1979/1980 KZ1000B models (LTD's) and the 1977/1980 KZ1000A models use a more rectangular looking rear caliper and rectangular rear brake pads that are held in place by two pins with jesus clips.

I think the early LTD's raer disc has less offset, and is a tad smaller in diameter. I don't have a LTD rear disc around to make sure!!!

Somebody with both discs on hand could tell you for sure!!!

Dr. Gamma wrote: The 1977/1978 KZ1000B models (LTD's) use a rear caliper that looks like a front caliper with a circular brake pad.

The 1979/1980 KZ1000B models (LTD's) and the 1977/1980 KZ1000A models use a more rectangular looking rear caliper and rectangular rear brake pads that are held in place by two pins with jesus clips.

I think the early LTD's raer disc has less offset, and is a tad smaller in diameter. I don't have a LTD rear disc around to make sure!!!

Somebody with both discs on hand could tell you for sure!!!

That info sounds correct to me. Usually 79 and and 80 are mostly the same as I just bought a rear 79 caliper and rebuilt and painted it to go on my bike. Of course I checked part numbers first and they were the same. Other front one's look the same but don't have the insulated piston for the sintered pads is all.

My caliper is the larger one which uses the rectangular brake pads.

So, if the wheels came off a 77 or 78 LTD then I do not have the matching caliper.

The plot just thickened however. One of the bolts which held on the front fender had stripped so I bought another set of 77 LTD forks to rebuild while I was waiting for other parts. After I installed the new forks the front wheel won't go on because the disc on the front is too big. I measured the front disc and it is 295mm diameter. What year used discs that were 295mm? This puzzle would be easier if I knew the exact year these wheels came from. Eventually I think I'll get everything back to a consistent year.

My bike is more of a Frankenstein than I thought.