front brake pulse

[wbeck257]

2006 S2R1000.

I've been experiencing worse and worse front brake pulse for the last 2k miles. At first it was just a little, but now it is pretty bad.
First thought, warped rotors. On the stand it didn't look bad, but I took the wheel off anyways.

I have a stand that we use to true up spoked wheels and I put the wheel on that. Set up some dial indicators and spun it.
It had a little movement in it, but it was the same for both rotors. I also measured the wheel itself, it was the same as the rotors.

So I felt confident that the rotors were good. Put the wheel back on, torqued everything down, and...
the pulse is still there.

Any ideas?

[Spidey]

Under light or hard braking?  Low speed or high speed?

I'd scuff up the pads and clean and scuff the rotors with brake cleaner and scotchbrite pads and then bed the brakes again.. 

[wbeck257]

Under light or hard braking?  Low speed or high speed?

I can feel it at low speed. But it does get expodentially worse at higher speeds.

I'd scuff up the pads and clean and scuff the rotors with brake cleaner and scotchbrite pads and then bed the brakes again.. 

How should the wear on the pads look? Mine are kind of tapered right now.

[ducpainter]

I can feel it at low speed. But it does get expodentially worse at higher speeds.

How should the wear on the pads look? Mine are kind of tapered right now.

Pads will always wear more at the leading edge.

Try cleaning everything and bedding the brakes.

Good info here

[hypurone]

Well, unless there are hard spots or contaminates on the rotors it is most likely warped rotors. I went thru all the procedures as a long shot (I knew they were warped from past experience) and nothing. As soon as I replaced them, S M O O T H....  [moto]

[wbeck257]

Well, unless there are hard spots or contaminates on the rotors it is most likely warped rotors. I went thru all the procedures as a long shot (I knew they were warped from past experience) and nothing. As soon as I replaced them, S M O O T H....  [moto]

I'm almost 100% confident that they aren't warped.
I've measured them in about 10 diferent ways. No indication of them being warped.
Last night I even put the bike on its stand and measured the distance from the rotor and the forks in 15 spots. Same distance, both side. I did the same thing on the wheel. So it is on straight.

Pads will always wear more at the leading edge.

Try cleaning everything and bedding the brakes.

Good info here

What about vertically?
And thanks for the link...

[Norm]

Maybe hot spots, for the price of stock ebay rotors, I'd try a new set & then pitch the old ones if it goes away.

[ducpainter]

What about vertically?
And thanks for the link...

I suppose if the pads didn't move freely on the retaining pins they could wear more on the bottom.

My monster tends to wear inside pads faster than outside...

If you have doubts about the pads clean up all the pieces and put in a new set...they're not that expensive...relatively.   

No problem.

[hypurone]

Maybe hot spots, for the price of stock ebay rotors, I'd try a new set & then pitch the old ones if it goes away.

You tomato, I say tomahto... same thing. 

[Bill in OKC]

Sometimes the buttons will freeze up - mine did it one time after washing it at a car wash - maybe a harsh soap there?  You can use a screwdriver or something to 'exercise' them and sometimes that will cure it.  If you are VERY careful not to get any on the rotors or use too much so it won't run, some wd40 or some type of light lube on the buttons will let them move easier and keep them from freezing up again.

[ScottRNelson]

Sometimes the buttons will freeze up - mine did it one time after washing it at a car wash - maybe a harsh soap there?  You can use a screwdriver or something to 'exercise' them and sometimes that will cure it.  If you are VERY careful not to get any on the rotors or use too much so it won't run, some wd40 or some type of light lube on the buttons will let them move easier and keep them from freezing up again.

If you really want to clean up the buttons, find an old allen wrench that is the size to fit in one, cut off the shorter bent part and put it in an electric drill.  Then spin the button while spraying a bit of WD-40.  The buttons will clean up nicely that way.  After all that, wash everything to get rid of any traces of the WD-40.  That will clean up any alignment issue.

[wbeck257]

Isn't the S2R1000 a semi-floating rotor, IE no buttons?

[ducpainter]

Semi floating rotors have buttons.

[wbeck257]

And they should spin?
Maybe I just don't understand how semi, or normal floating rotors work...

[ducpainter]

And they should spin?
Maybe I just don't understand how semi, or normal floating rotors work...

The buttons on a semi floating rotor have the clearance to spin, bit don't do so easily because of the wave washer on the back side..

The full floating buttons will spin easily.