'03 R1150R rear brake rotor hot

[R1150Rclean]

So I replaced the rear tire and got a good look at the brake pads, getting thin, and "about" even wear with 11k on them. Cleaned the pads, brake assembly, and lubricated the pins and ends of pads as well as the back side, but when I stop the bike the rear rotor is always hot, and the fronts are cool, even when I use them to come to a stop. Any idea why? Rear pads are a lot more worn than the front pads.

[Biff's R]

Just check that your foot isn't accidentally riding on the brake lever.

[R1150Rclean]

Just check that your foot isn't accidentally riding on the brake lever.

Well that is something I will look at, do not think so but all the same will keep an eye on my foot.

[jcridge]

You are most likely not grabbing enough front brake by the sounds of it.

The front brakes on your bike have twice the stopping power of the rear and have over twice the surface area comapred to the rear. If you are applying the brakes equally, the rear brakes will wear faster. Given that you rear pads are getting thin at 11K would be a good indication.

The rear pads are not the same thickness when new, so if you have pads that are, and they are thin...replace them.

Heat is disapated through the pads during braking, having thin pads causes heat to build-up in the rotors, that normally wouldn't be there. The front rotors have a huge surface area and direct access to moving air, the rear rotor is small and the air surrounding it is not direct.


John

[R1150Rclean]

Okay, this is what I am going to do, ride my bike around the block without using the rear brake and then see how hot the rear rotor is. Will get back.

[Buckster]

When I replaced my pads a couple of years ago, I found that the calipers were not retracting back like they should. They were pretty dirty and I gave them a good cleaning and greased them up the best I could without taking them totally apart.-couldn't figure out how- I believe there was a post by cyclerob on how to take them apart. You might do a search on the subject.

[regjacksn]

I had the same problem. The "floating" pads weren't floating - they should move back and forth on two pins at the front and back of the assembly. My mechanic installed the assembly and gently tapped back and forth (on the front pin in my case) while squirting lubricant into the pin assembly. Mine got so bad the wheel was locked!
Reg

[R1150Rclean]

Okay, thanks for all the input. If I stay off the rear brake and stop using the front brake the rear rotor is "warm", can hold it with my hand no problem. So I think as you have pointed out the rear rotor is poorly cooled, AND I may just have been lightly pressing on the end of the brake arm with the side of one pair of boots I wear (thicker sole). Never really looked down to see how close my foot was to it until it was mentioned. I greased the pivot pin and end of the pads and they are "loose" so they do not seem to be locked up now. Also have more pad than I thought, and it should last another 5k easy if I keep my foot off the brake!

[CycleRob]

The Aluminum caliper carrier arm likely is not sliding freely in the caliper rubber bushings. It comes apart by hand just by sliding out the carrier arm (expanding the length of the rubber bellows) while you unseat both bellows ends off their individual retention ridges. Clean out the cavity of the rubber bellows with a paper towel twist and small screwdriver. Be patient and don't push in too deep against the bottom or you'll go through. Here it is apart:


Note the mating stud and socket on the caliper:


And of course, some pointers on the caliper parts:


It all looks complicated, but it's an easy job if you have internal snapring pliers and use the brake pedal to extend the pistons together with a "tool" to ensure they stay even as they come out. Remember; Do NOT use brake cleaner on ANY rubber parts!!! Use new brake fluid as a solvent cleaner. This is why.


.

[R1150Rclean]

CycleRob,
Checked it out, the caliper slides freely on the the two pins so that is not the problem. I did notice that the front caliper piston (closest to the engine) is pushed out first when pumping the brake peddle, so I extended both pistons and lubricated the outside surfaces, and pushed back in. I really do not know what the brakes were like when I got the bike, so the wear could be from the previous owner.

Looking at EBC organic pads and the Beemerboneyard sintered pads as replacements, and suggestions?

[R1150Rclean]

Okay, re-lubricated all the brake pad metal backing contact surfaces (i.e. the surface of the housing that the end of the metal back slides in, metal wear plate in CycleRob's picture) using a Q-tip and brake grease and the pivot pin that the pads hang on, also lubricated the outside "round" surfaces of the pistons when they were fully extended, and took for a test ride for ~1 mile at 35 mph, used the rear brake 2x at the beginning to make sure the pads were settled and then only used the front brake. This time the rear rotor was barely warm to the touch So maybe a pad or piston was sticking after all.

[tartanstorm]

Hi all,

I recently bought a R1150R and the owner told be it has linked brakes and soem very clever stuff going on, such as if you break with the rear just sometimes it will split the force 70:30 but if you use it a lot it will change the distribution to 50:50 and when you use the front it is always 80:20 or something like that.

I also have a very hot rear brake rotor and have tried all the tricks, but the linked braking explains why even using the front only the rear gets warm. I think there is an underlying problem however as the former owner had to replace the rotor/disk at 46000km way too early. BMW have 'tested' (i.e plugged it into a computer) and told him it is normal, but in my 20 yrs of biking its not right to wear out the rear before the front especially as it is rarely used...

Hope this sheds some light on the matter.

David.

[sweatmark]

Linked brakes on R1150R only applies to the Integral ABS system.

Presupposing that your bike is equipped with iABS, can you confirm that the spacer/washer is installed between rear wheel and the final drive? That washer is needed to offset the the wheel and attached brake rotor due to presence of the ABS tone ring, and thus align the rotor correctly within the brake caliper attached to final drive.

Part 36 31 7 653 286  WASHER

If the washer is omitted on certain iABS bikes, then misalignment of brake rotor and caliper will cause friction, heating, premature pad wear.