03-29-2016, 01:22 PM
My rear ABS acts similarly, and I think the way the rear ABS works on my bike is odd. I tested mine several times at speeds from 30 to 50 mph and the results are always the same. I think the noise (clunk) is caused by a combination of the brake pads releasing the rotor and allowing the wheel to rotate after momentarily locking, and the chain slapping as the wheel quickly begins to rotate again. The rear ABS on my bike certainly does not act like any ABS I have ever experienced while driving a car, and I have used ABS in a car many times while driving on icy, winter roads in upstate NY. The ABS in the cars I have driven functioned by pulsing the brake system pressure off and on at several hertz (you can feel it in on the pedal), but on my bike there is none of this high-frequency pulsing. It feels like the frequency that the rear ABS operates on my bike is much slower. I posted a thread on this topic several months ago and another member responded with information describing how the CB1100 ABS worked - so there is a better explanation out there if you're willing to look for it.