Brake Disc Recommendations

[kltk165]

Hey folks. 2011 R1200RT. I have a vibration when using the front brake. Only when applying front brake. If I apply rear brake only I feel nothing. I'm assuming I have a bad rotor. Or two. Checked the Beemerboneyard website and they have ABM rotors. I see Galfer has the Wave. I checked the EBC online catalogue and it appears they don't offer a rotor for the 12/07-13 R1200RT. Any recommendations?

[6speedTi]

Make sure your caliper is not hung up on the mounts. Try removing the caliper and reinstalling and check for free movement. Also spin the front tire and see if you can see the rotors being true. Check the obvious before spending money.

[kltk165]

Thank you. I'll do that...

[Bernie]

I have been using the ABM disc's from Beemerboneyard on my 2007 R1200RT, front and rear.

Have you tried to clean the discs on both sides with a Scott Brite type of pad? I used to get a slight pad build up on the disc, that would cause a vibration when braking lightly. After cleaning them,it would smooth out again. I was told it maybe caused by pad build up, caused from keeping the front brakes applied after a stop, while standing at a light. I now keep the rear brake applied to keep my brake light on while being stopped.

[kltk165]

Will add that to the list of things to do before making any purchases. Thanks!

[Guest Kakugo]

Before buying new rotors, make absolutely your whole front end is sound and inspect your rotors carefully.

 

In 20+ years of riding and tinkering with bikes, I am yet to see a "bad" brake rotor. Unevenly worn due to a mismatch between brake pad and rotors materials? Yes, but only on track bikes. Bobbins freezing solid? Yes, but it's far rarer than one may think. Rotors snapping? Seen that as well. But I am yet to see a bent rotor as some people assume. I know it's technically possible, but I am yet to see one.

 

While we are at it, where do you feel the vibration? In the brake lever? In the handlebars? Through the whole front end of the bike? That may provide some more insight on what to look for before committing to a rotor change.

 

[Tourmaster]

On my '12 R1200RT the front brakes developed a 'pulsing' feel, the dealer replaced them (warranty) due to warping at the 10K km check. The replacements have been flawless.

 

Rick

[dirtrider]

Hey folks. 2011 R1200RT. I have a vibration when using the front brake. Only when applying front brake. If I apply rear brake only I feel nothing. I'm assuming I have a bad rotor. Or two. Checked the Beemerboneyard website and they have ABM rotors. I see Galfer has the Wave. I checked the EBC online catalogue and it appears they don't offer a rotor for the 12/07-13 R1200RT. Any recommendations?

 

Afternoon kltk165

 

Tell us a little more about the vibration-- such as-- does it just shake the front end or can you also feel the pulsation as a vibration in the front brake lever?

 

If you can feel the vibration in the hand lever then you probably have a bad front brake rotor (did the problem appear after the last front tire change?). If your problem showed up after the last front tire change then you might have a bent rotor.

 

On the other hand --if the front end shakes but you don't feel it in the hand lever then you might just have a stained or pad disposition problem & that can usually be repaired by sanding / cleaning the front brake rotors. Severe pad disposition can be difficult to remove but it usually can be repaired at home with a lot of effort.

[kltk165]

Thanks DR and Kakugo. It's not coming through the brake lever so much as when the brake is applied the front end shudders. If that makes sense. Not like the bike is going to fall down, just feels like when the brake is applied you know something isn't straight. Again, if that makes sense. I'll Scotchbrite the discs real good as Bernie suggested and see what happens there first and report back. Probably Friday.

[dirtrider]

Morning kltk165

 

Without feeling it (the judder) thorough the brake lever that points more to rotor staining or pad disposition than to bent or warped brake rotors.

 

Scotchbright & brake clean is a good place to start but might not (probably won't) be enough to remove severe pad disposition.

 

Does your bike still have OEM brake pads or are they aftermarket?

 

 

[The Rocketman]

I just bought one of these rotor flex-hones the other day. Its on its way.

http://www.amazon.com/Brush-Research-Flex-Hone-Rotors-Fine/dp/B007INTEFY?ie=UTF8&psc=1&redirect=true&ref_=oh_aui_detailpage_o05_s00

 

Trying to get rid of front brake squeal. That might be more of what you need. To clean up the rotors and add that new, cross-hatch pattern.

[dirtrider]

 

Trying to get rid of front brake squeal. That might be more of what you need. To clean up the rotors and add that new, cross-hatch pattern.

 

Morning RM

 

Before using that hone on the brake rotors you might remove your front brake pads then take a file (or block of wood & sandpaper) & lightly chamfer the outer edges of your brake pads. A slight 45° chamfer on the pad material edges will usually eliminate the brake squeal.

 

One of the big issues with those brake rotor hones is you can't get to the insides of the front rotor surfaces without removing the brake rotors from the wheels. That can bring on it's own issues.

[The Rocketman]

Thanks DR. Already tried the pad chamfer and it didn't work. That's why I posted this the other day about re-using brake rotor bolts.

http://bmwsporttouring.com/ubbthreads/ubbthreads.php?ubb=showflat&Main=87180&Number=958612#Post958612

 

I'm all prepared to remove the rotors and try the hone now. Couldn't hurt to get all the old pad deposits off anyway. I replaced the rear pads with CL but they never sqealed and still don't. Fronts have plenty of meat, but don't know the brand. Been squealing a little since I got the bike a few thousand miles ago, but it seems to have gotten worse.

 

Hopefully this will fix it, or I'll pick up a new set of CL's for the front too.

[dirtrider]

Morning Rocketman

 

Be very careful in using that hone as it actually removes some rotor material. In using a hand held drill or 90° die grinder it is possible to put divots in the rotor surface.

 

I usually put the rotor in my lathe when using one of these surfacing hones (actually I like using a DA sander better than the hone).

 

You might try removing your calipers then having someone turn (& keep turning) the front wheel as you dress the rotor outside surfaces then flip the rotors over & re-bolt to the wheel & repeat on the inside surfaces. (just be careful to keep both the rotor & hone moving)

[The Rocketman]

Will do.

[kltk165]

Ok, cleaned the discs with Scotchbrite pad and Brakleen. Gave them a good scrub. Much better than before but still a judder on application of the brakes. Not nearly as pronounced as before. Also spun the front wheel and looked as best I could, the discs don't appear warped. If they are it would be very slight. Anything more aggressive that can be used to make them even better? Or would cleaning them more often eventually clean up the remaining residue? Thanks.

[Guest Kakugo]

Ok, cleaned the discs with Scotchbrite pad and Brakleen. Gave them a good scrub. Much better than before but still a judder on application of the brakes. Not nearly as pronounced as before. Also spun the front wheel and looked as best I could, the discs don't appear warped. If they are it would be very slight. Anything more aggressive that can be used to make them even better? Or would cleaning them more often eventually clean up the remaining residue? Thanks.

 

Try taking your brake pads off (one side at time) and having a look. They could tell a lot about these issues.

Also gid out your torque wrench and a T30 bit and check all rotor bolts are torqued to specs.

[dirtrider]

Ok, cleaned the discs with Scotchbrite pad and Brakleen. Gave them a good scrub. Much better than before but still a judder on application of the brakes. Not nearly as pronounced as before. Also spun the front wheel and looked as best I could, the discs don't appear warped. If they are it would be very slight. Anything more aggressive that can be used to make them even better? Or would cleaning them more often eventually clean up the remaining residue? Thanks.

 

Morning kltk165

 

Seldom if ever is a warped brake rotor an issue on the BMW, it is almost always either a pad deposition issue or a rotor staining problem.

 

Both of the above are difficult to fully remove with just brake clean & a Scotch pad. I have seen the pad transfer issue so bad that I have had to remove the brake rotors, mask them off, then put them in my glass bead cabinet.

 

The problem you are facing is 2 fold-- first it is very difficult to work on the back side of the rotors when they are still on the wheels & secondly it is a fine line between going too aggressive on the cleaning media therefore changing the brake rotor friction surface & getting them clean enough to stop the juddering.

 

Does your bike still have the original BMW brake pads or are you using aftermarket? That can make a difference in how to attack the problem.

 

I guess my suggestion (as of now) is to ride the bike as is for a short time then re-clean the rotors using Scotch pads & brake clean again (do this a few times). If that eventually clears up your judder issue then all is good. If the problem then still remains then you will have to try a more aggressive approach.

 

New brake rotors usually fix the problem so riders think the old ones were warped but the replacements just get rid of the staining or pad deposition. With 4 piston calipers that caliper design can handle a lot of rotor warpage or lateral run-out but even a couple of ten-thousandths of rotor thickness variation (from pad deposition) can cause a pretty severe judder issue.

 

On rotor staining it doesn't even need to have a thickness variation as the staining causes a difference in brake pad friction as they cross the stained areas under braking (that's the judder you feel). Plus staining isn't always visible to the untrained eye.

 

 

 

 

[The Rocketman]

Or....

If you want to make a trip from NJ to Wrong Island, or just cover the cost of shipping back and forth, I'd be happy to lend you my new brake rotor flex-hone as soon as I'm done with it. Should be getting to my rotor clean-up job sometime tomorrow or early next week.

[Rogerl]

I had the same problem with the brake judder on my 2008 R1200R. I measured the runout with a indicator and found the rotors were flat. I tried cleaning the rotors with scotch brite pads but I could not get the back side clean like Dirtrider stated above. I ended up taking the rotors off and making a face plate for my wood lathe so I could spin them and used some fine sandpaper to sand both surfaces. This removed all of the deposits on the discs and the judder went away.

 

Just my 2 cents

Roger L

[kltk165]

Sorry, I know the question was asked earlier and I missed answering. These are not the stock pads. They are the Brembo Red pads. Thanks to everyone for the assistance and suggestions.

[Guest Kakugo]

Sorry, I know the question was asked earlier and I missed answering. These are not the stock pads. They are the Brembo Red pads. Thanks to everyone for the assistance and suggestions.

 

Junky pads.

[The Rocketman]

I used the brake rotor flex hone yesterday, and my rotors sure look a lot better. Shiny silver, clean and pretty swirl marks everywhere. Haven't had a chance to ride yet to see if the squeal is gone. Hopefully later this afternoon I'll report back. Broke three T30 Torx bits reinstalling the rotor bolts, all on the ABS ring side. Right side (5) went fine. ABS side, 3 out of 5 went great; last 2 broke three bits. Even at 24 Nm, I guess Craftsman bits can only take so much. No cross-threading and bolts went in smooth. Bits only broke at the very end. The whole job took maybe 2 hours, and would have taken less, if I had not forgotten to put back the axle spacer. Had to undo and redo after I thought I was done.

 

Again, if it works, I'd be happy to lend you the hone to see if it helps your problem. Or I guess you could buy one too...about $35.