Compatible rotors?

[Mywalletsgon]

Just picked up my first 1979 xs1100 special, so just diving into parts availability. Can anyone provide information about the rotors as to what other years are compatible or new part options?

[cajun31]

All year model rotors are compatible. The difference being that the earlier rotors were not slotted. They all still work though. You can do a search for replacement rotors on Ebay. Of course some are better then others. I have never had the need for aftermarket but several of our users may chime in with their reviews of those they have used.

[cajun31]

Just wanted to add that starting with the 1980 specials they slotted the area that the brake pads rub against. Because of those slots they had to indicate which were for the right side and left side and marked them with an L and R. The rear disc also has an R on them and can be used on the rear or the right front. The 80 standard still had the solid unslotted discs. I have never owned any of the standards but I would think that the discs are completely universal and can be used on the front, left or right side. Quite a while back now we had many users that actually drilled multiple holes in them in a pattern. The premise being that with those holes as well as the slotted ones kept the rotors from getting so hot.

[DiverRay]

It wasn't for heat, it was to stop in the rain! I had my then brand new 1978 rotors drilled at a machine shop for that reason. I lived just South of San Jose, CA at the time and was able to ride year-round. My first ride in the wet in late '77 had me go through a stop sign with all the brakes applied! That is when I had the rotors drilled, and it stopped no matter what after that.

[cajun31]

It was actually for both. I hadn't thought about rainy conditions. One of the drawbacks to the holes or slots is that the pads wear quicker. I guess the benefits outweigh that.

[DiverRay]

With the drilled rotors, I ran the factory pads until I sold the bike at 35K miles. So no, it doesn't cause much extra wear.

[cajun31]

You had a very good experience with those pads. I had googled the pros and cons of drilled rotors on motorcycles and AI, which you have to take into consideration stated one of the cons would be added pad wear as well as in certain conditions cracks developing between the holes. I also did a search on the later slotted all the way through rotors on the later xs1100's and AI basically said it can cause catastrophic failure, which we all know is not true.

[DiverRay]

As I said, a machine shop did the drilling, and there was a clean up on the holes. You should ALWAYS just tap the holes with a bigger drill to chamfer them. This takes off the hard edge that causes pad wear and rotor failures.