796 Front Brake Woes

[cyberswine]

Just over 12k kms - 8k miles - and I'm getting severe grabbing on the front brakes at slow speed.  It's been an issue
before and usually went away with some hard braking.... fast or slow didn't seem to matter.  Now it's present most of the
time.  Pads have plenty of material, surely the rotors would feel bad at higher speeds if they were out of true?  No
grooves in the rotors.  Def not an ABS issue as it's way to slow and severe.  Just searched for sim threads without
success...... I'm planning on removing the pads from both sides and cleaning all the surfaces.   Any other
suggestions/solutions or things to look for before I start?

[ungeheuer]

There was talk of M1100 rotors (same as 796?  I dunno) warping.  Some had 'em replaced under warranty. 

... you'd be able to confirm or eliminate by spinning the wheel by hand and watching the rotor clearance between the pads (at the risk of stating the bleeding obvious - there should be little or no variation).

I think at higher speeds its less noticeable because of the increased rotational frequency - what manifests itself as grabbing at slower speeds may be less perceptible vibes at higher speed. 

[Howie]

Are you talking about grab (overly sensitive to initial brake application) or pulsation?  If the brakes are grabbing you can try cleaning the surfaces using brake cleaner and sanding the pads.  put a slight bevel on the leading edge, top and bottom to help bedding in.  Clean the rotors with brake cleaner and a Scotchbrite pad you are getting a pulsation and the bike is under warranty get the bike to a dealer.  If the bike is out of warranty while you are cleaning make sure the buttons are clean and mike the rotor.  The rotor blade not being able to move on one or more buttons will cause lateral run out, like a warped rotor.  More than .02mm. variation of rotor thickness you need new rotors

[mszilves]

I've had similar issues of the front rotors on mine "pulsing" at low speeds. The dealer confirmed I had warped rotors and replaced under warranty. After being replaced, it did it again, and once again dealer confirmed bad rotors and replaced both fronts under warranty a second time. This all within 6 months last year.

Now once again, mine are doing the "pulsing" at low speeds. I've cleaned the rotors, installed new pads and the issue is still there. It's only very slight, but it is annoying. I noticed this especially on a track day last month. I'm now debating on calling DNA and seeing what they have to say, as I don't particularly like/trust my dealer...

[cyberswine]

Thank you for the responses.  To clarify, it's a repetitive grab that can give me a kind of kangaroo slow stop.  I was thinking glazed pads but the bike is still under warranty and given the possibility of rotor issues I've taken the safe route and booked it in at the dealership.  I'll post the end result on the thread in case anybody else can benefit.

[cyberswine]

And there you have it.  Three out of three got it right:  the dealership is replacing both front rotors under warranty