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#1020515 - 10/09/18 04:27 AM Pulsating Front Braking 09 R1200 RT  
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Bigfish Offline
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Vista, California (San Diego ...
Coming from an 04 R1150 RT, I never experienced a couple of these sensations I am feeling on my 09 R1200 RT with only 20,000 miles. Only 2000 miles of me riding it though.
When trying to slowly come to a stop at stop lights, I am getting a pulsating sensation. Almost as if the rotors are warped. Only when using the Front brake lever.
Also, I have noticed the rear brake occasionally gives me feedback... it kicks back in an upward sensation and feels like a knock,knock. I am thinking it is the ABS doing its job. Never once did I feel this on my 04 and I rode that bike over 90,000 miles. Maybe I'm just riding a little harder or is the 1200 more sensitive to rear breaking?
What procedure should I take for the uneven front braking?

BTW, at speed, the bike is nice and smooth and rides like a dream.


Bigfish
IBA #47337 50cc May 2011
"Dry-Town" Crew, San Diego
'04 R1150RT

My Motorcycled States
#1020522 - 10/09/18 09:20 AM Re: Pulsating Front Braking 09 R1200 RT [Re: Bigfish]  
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Bernie Online
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Jax, FL
To eliminate the front brake pulsing, try to clean both sides of the disc’s with a 3M scoring pad or steel wool. You most likely have a coating of melted brake pad material, which happens when you leave the front brake applied, while waiting at traffic lights.
You can try the same with the rear disc, but I think what you are feeling is the ABS working.


Bernie
Jax, FL
2018 R1200RT, Alpinweiss, starting out fresh.
2007 R1200RT, Double Silver 188,700 Smiles, SOLD
2000 R1100RT, Opal 104,000 Smiles, SOLD
BMW-MOA, BMW-RA,
AMA, BMW-NEF,
#1020524 - 10/09/18 10:02 AM Re: Pulsating Front Braking 09 R1200 RT [Re: Bigfish]  
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dirtrider Offline
The Oracle
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Ohio
Originally Posted by Bigfish
Coming from an 04 R1150 RT, I never experienced a couple of these sensations I am feeling on my 09 R1200 RT with only 20,000 miles. Only 2000 miles of me riding it though.
When trying to slowly come to a stop at stop lights, I am getting a pulsating sensation. Almost as if the rotors are warped. Only when using the Front brake lever.
Also, I have noticed the rear brake occasionally gives me feedback... it kicks back in an upward sensation and feels like a knock,knock. I am thinking it is the ABS doing its job. Never once did I feel this on my 04 and I rode that bike over 90,000 miles. Maybe I'm just riding a little harder or is the 1200 more sensitive to rear breaking?
What procedure should I take for the uneven front braking?

BTW, at speed, the bike is nice and smooth and rides like a dream.


Morning Bigfish

First thing you need to determine is if your front brake problem is pad disposition or something warped or bent.

Can you feel the pulsation in the front brake lever? If so then you probably have a brake rotor warpage or something mechanically wrong with a front brake rotor.

If the lever is not pulsating then more than likely you either have brake pad disposition on the rotor surface or rotor staining (rotor staining usually comes from parking the bike long term with wet brake pads).

If it turns out to be rotor staining or pad disposition then cleaning it is not always an easy thing. As Bernie mentioned a Scotch pad (red one) used to scour the rotor surfaces will sometimes work but it usually also takes some brake clean to even have a chance of removing the problem. Do Not use steel wool or anything ferrous on the stainless steel brake rotors as the small steel particles can lead to future problems of more staining. You can use stainless-steel steel wool but it probably won't work as good as a Scotch Pad or sanding.

If it turns out to be rotor staining or pad disposition then in severe cases you might even have to sand the rotor braking surfaces or even remove the brake rotors & very lightly glass bead them to remove the problem.

What happens is--with either rotor staining or pad disposition the brake rotors have a higher friction area in the stain/disposition area so as the working brake pads pass that area you get more aggressive braking in those spots, therefore brake pulsation.


D.R. ___
Sent from my rotory dial wall phone!
#1020538 - 10/09/18 01:21 PM Re: Pulsating Front Braking 09 R1200 RT [Re: Bigfish]  
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Bigfish Offline
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Thanks Guys, I've never heard of a red scotch brite, but I will be stopping by Home Depot in hopes they have them. Hoping this is the easy solution.


Bigfish
IBA #47337 50cc May 2011
"Dry-Town" Crew, San Diego
'04 R1150RT

My Motorcycled States
#1020551 - 10/09/18 04:13 PM Re: Pulsating Front Braking 09 R1200 RT [Re: Bigfish]  
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TEWKS Offline
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Quote
I am getting a pulsating sensation. Almost as if the rotors are warped.


Hopefully the easy solution works for you but I had the same issue on my 05 RT and it was warped rotors. Luckily a warrantee fix at the time for me.

Pat


"If at first you don't succeed, keep on sucking till you do succeed" Curly Howard
#1020580 - 10/10/18 02:01 AM Re: Pulsating Front Braking 09 R1200 RT [Re: TEWKS]  
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Bigfish Offline
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Originally Posted by TEWKS
Quote
I am getting a pulsating sensation. Almost as if the rotors are warped.


Hopefully the easy solution works for you but I had the same issue on my 05 RT and it was warped rotors. Luckily a warrantee fix at the time for me.

Pat


Tewks, how did you confirm the rotors were warped? Did the dealership do a test? I've replaced front rotors before and it was a simple procedure as long as you heated up each bolt to 160 degrees. But that was due to the discs thickness being slightly under spec.
I was trying to put a straight edge on the outer surface and it seemed square. Anyone have a favorite method to test if a rotor is warped?


Bigfish
IBA #47337 50cc May 2011
"Dry-Town" Crew, San Diego
'04 R1150RT

My Motorcycled States
#1020593 - 10/10/18 09:42 AM Re: Pulsating Front Braking 09 R1200 RT [Re: Bigfish]  
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TEWKS Offline
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Tewksbury, MA.
This probably sounds silly but, they warped under harder use out in Colorado. Big/Fast roads (hard braking) compared to back east. Anyway, the dealer determined they needed replacement to fix the pulsating that developed. IIRC, there was an issue with the rim's rotor mounting surface that was out of spec which helped make it a warrantee claim. Sorry I can't give a better diagnosis.

Pat


"If at first you don't succeed, keep on sucking till you do succeed" Curly Howard
#1020596 - 10/10/18 10:43 AM Re: Pulsating Front Braking 09 R1200 RT [Re: Bigfish]  
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dirtrider Offline
The Oracle
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Ohio
Originally Posted by Bigfish

Tewks, how did you confirm the rotors were warped? Did the dealership do a test? I've replaced front rotors before and it was a simple procedure as long as you heated up each bolt to 160 degrees. But that was due to the discs thickness being slightly under spec.
I was trying to put a straight edge on the outer surface and it seemed square. Anyone have a favorite method to test if a rotor is warped?


Morning Bigfish/ Pat

You can't compare the 2005 BMW 1200RT to the later (like 2009) brake rotor issues. The early 1200RT's (2005) had a number of front brake rotor issues as that bike still used the older I-ABS system. BMW had a few service bulletins on the 2005 front brake rotors & even the front wheels. The first BIG problem was incorrectly made front wheels with the brake rotor mounting pads out of spec (this caused all kinds of brake pulsation issues).

The other was a stack-up issue with the brake rotors not sitting correctly due to the tone ring not fitting correctly, there was also a rotor mounting hardware issue.

Bigfish-- The correct way to confirm warped rotors is to use a dial indicator to sweep the spinning brake rotors but unless drastically warped a slightly warped brake rotor seldom causes pulsation as the 4 piston caliper pistons & floating rotors just move to compensate for the slight warpage.

The thing that causes a noticeable brake disturbance (pulsation) is brake rotor thickness variation & to measure that you need to mike the brake rotor thickness all the way around both brake rotors. (though, BMW hasn't had this issue in many years now)

The big cause of later BMW motorcycle brake pulsation is either staining or pad disposition.

A quick test for severe brake rotor warping or thickness variation is IF you can feel the pulsation in the front brake lever as that lever movement is a direct feedback from the rotor to pad interface.

If you have brake pulsation but can't feel it in the brake lever then you almost certainly have a varying friction area causing the problem (like staining or pad disposition). If you are experiencing a lot of front brake lever pulsation then look for brake rotor thickness variation, or the front rotors tight on their mounting spools, or sever warping.

If you have brake pulsation without matching lever movement then most likely you have staining or friction material buildup.


D.R. ___
Sent from my rotory dial wall phone!
#1020644 - 10/10/18 07:40 PM Re: Pulsating Front Braking 09 R1200 RT [Re: Bigfish]  
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Bigfish Offline
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Bigfish  Offline
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Vista, California (San Diego ...
Good news I think. on ride to work this morning, I was concentrating to feel if front brake lever was giving feedback. I did not feel anything so maybe a good scotch brite cleaning will do the trick. I will update the result after cleaning. Thanks for all the input.


Bigfish
IBA #47337 50cc May 2011
"Dry-Town" Crew, San Diego
'04 R1150RT

My Motorcycled States

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