It is a known issue, but I am unaware of proof positive of just what the cause is. My personal thin ice foundation theory is that the proportioning valve in the brake hydraulic line is vibrating in and out of function due to heat. I have also wondered about the rear master cylinder adjustable link being out of spec, too long. The problem seems not to occur if the front brake is applied at the same time.
If you do some searches, you will see that it has been identified as primarily a hot weather related item. As noted above, it is a well documented problem that Honda has not come with a fix for or pin down the cause.
I recall a post/thrhead by Fred H. that a lot of suggestions. I do remember that some people were able to get their rear brake rotors, calipers etc replaced under warranty...but I'm not sure that solved the problem.
I just experienced the rear brake shimmy everyone here is describing. Found this thread on my first search. Wow.
Anyway, at the end of a long ride (300 miles) mostly twistys with speeds averaging 40-50 mph ... I started feeling a very significant vibration when I applied the rear brake. The temp was around 85F. Yes, I use both brakes and yes I ride very aggressive. For the last 15-20 miles I simply used the front brake and when I tested the rear brake at the end of the day the vibration was gone.
It has been a very hot summer here in the south east. I have ridden long trips in temps hovering in the upper 90's and have never experienced this type of issue before.
This afternoon I'm planning on dropping the caliper, inspecting the brakes and giving it a good cleaning. If I find anything specific I will certainly post the results here.
I had that too... Tried a set of Kevlar pads and never had it occur again... Bad thing is the Kevlar pads did not work (at all) in the rain... Went back to OEM's and EBC double H's and the vibration returned... It has to do wiht the pad material and the brake configuration (linked)... I'll bet a guy with time in interest could come up with a fix for it... Maybe a change in the proportioning valve settings...
I took my rear brake pads out to clean and inspect. Here is what I found. Can anyone tell me why the brake pad on the left has bar marks and the pad on the right has round marks? Yes I know the round marks are from the brake pistons.
happened to me tonight coming home from work. only 3k miles on my bike, 2 months old. was intermittent. startled me a little bit. i seem to use my back brake a little more than i probably should(percentage wise) cause i had my front wheel lock up and pop me down hard on my vtx 1800 in february on a damp morning. so i am kinda nervous about heavier front braking.
i'm sure al gore is right, global warming is most likely the cause. rick perry just calls it summer in texas. :thumbup: