Rear brake rotor issue

[camos]

Today while checking the air in the rear tire I noticed the outer part of the brake rotor was much looser than I had remembered it to be. It's the part of the rotor that is held on by what appear to be rivets. Mine is loose enough that it can be rocked back and forth by hand. This does not seem to be the way it should be.

 

I'm thinking the rotor needs to be replaced but what could have caused it to become as loose as it is? Anyone ever encountered a situation like this before?

[Peder_y2k]

I've only read about the sloppy rivets. The manual makes no mention of this condition either. I would think the rivets being a little loose is no issue as there is plenty of material there to maintain the connection between rotor and the mounting plate, so it's not going to fall apart anytime soon.......just may get a little noisy with some clicking sounds. The looseness will only continue to get worse with usage. I suggest you start looking for a good solid replacement and when you find a cost effective deal, buy it. Alternately, maybe the rivets can be tightened in an appropriate press.

-Pete, in Tacoma WA USA

[Venturous Randy]

Aren't the rotors on a MKII supposed to float some?

RandyA

[camos]

I have no solid knowledge about the rear braking system but I do believe there is supposed to be a floating component in there somewhere. I had thought the caliper was the part that did the floating, not the rotor. Perhaps there is a two part float system that included the caliper and the rotor. When I had the rear wheel off I checked the brake pads and the rear caliper parts did not look to me much different from the front calipers.

 

Hopefully Peter is right and just replacing the rotor will fix the issue, however, if there is something in the caliper that is not floating properly then perhaps that is a reason for the rotor to have been wiggled back and forth enough to loosen the rivets.

 

I think rotors are still available from EBC but I should pull the caliper and give it a good examination.

[Peder_y2k]

I went out to the garage and examined the way the rear disc (non-floating) was put together on my '88VR, and it is indeed a hollow rivet with flat head on the outside, and washer on inside, with pressed over end. If it were my bike, I'd remove the disc and use a tapered punch with big hammer and tighten those rivets up. Worst case scenario is cracking the hollow rivet by whacking it too hard or overdoing it.

-Pete, in Tacoma WA USA