[SkyDork]

I agree probably CCT, but what about the other issue of the break lever wiggling around when I shift from 2nd to 1st - it's not a little movement, it's a lot. Seriously feels like there is a rod connecting the two levers, and the rod is not secured and the entire assembly will fall off.

Reminder that I have 6 years riding experience all seasons (including winter). I have beat the hell out of my CBR, and I've never experienced this before.

The feeling in the brake lever is probably nothing to do with the brakes themselves. It's likely clutch shutter from the slipper clutch activating to limit the back-torgue to the wheel. Depending on what the Engine Braking settings are, how fast you're going when you're downshifting, and whether or not you have ABS on the bike, will determine how the rear brake feels. There's nothing mechanically linked and I think what you're feeling is a byproduct of the bike working against your technique. Downshifting form 2nd to 1st should be done at relatively low speeds to prevent this from happening and upsetting the chassis.

 

[SkyDork]

Yes, this bike has ABS, and when it occurs I am going slow, approaching a stop light for example, I'm not going fast, nor blipping the throttle, simply slowing down maybe 5 to 15 mph, and shifting into first. There's no way the slipper or ABS should be kicking in. Also I know it's not mechanically linked, but that's how it feels - there is some correlation between shifting into first and the rear brake lever reacting with it. Again this doesn't happen all the time - so far in over 300 miles I'm guestimating a dozen times.

Next time it happens i'm going to pull over and make a notes as to exactly what occurs. Also, I just checked my rear brake, and it is solid, doesn't wiggle around at all.

Well, you'd be surprised at how low the slipper clutch will activate. Especially if you aren't rev matching and letting out the clutch at 15mph. I would most definitely expect some clutch feedback even at those speeds. Try rev matching properly even when downshifting to see if it changes the symptoms at all.

The ABS turns off automatically at 5mph and is inactive below that speed. If you're really mashing down on the rear brake when this transition is happening, you might be getting slight wheel hop or shutter as the ABS module change modes. That in turn would send more torque through the clutch which would activate the slip mechanism. Who knows. It's hard to tell what technique you're using in this condition and if that is contributing to the difference you're feeling.

Try blipping the throttle on the downshift to first. Also try using less rear brake when stopping. See if these things change the characteristics.