2011 GSA 1200 Rear Rotor

[Fat Bear]

What would the causes be for the rear rotor on a 2011 GSA 1200 with 30K kms to become warped?

[RegularRider]

Excessive heat , inability to move at the mounting points.

Joe,

[Fat Bear]

I'm just not sure what I should be doing to remedy the situation? It seems to me that having an issue like this with only 30K kms is premature to say the least. The rear wheel is not spinning freely - in addition to replacing the rotor, what other precautions should I consider taking to prevent recurrence?

[PGlaves]

I'm just not sure what I should be doing to remedy the situation? It seems to me that having an issue like this with only 30K kms is premature to say the least. The rear wheel is not spinning freely - in addition to replacing the rotor, what other precautions should I consider taking to prevent recurrence?

Something is binding. I don't recall off the top of my head if that is a floating caliper or not. If it is, the pins under the rubber boots need to be cleaned and greased with brake caliper grease. If not, then probably pistons are bidning in the caliper bore. It needs a thorough cleaning and/or a rebuild.

[Kent Niederhofer]

I think the answer to your original question is in a comment you made about the rear wheel not spinning freely. It sounds like the brake is binding on the rotor, thus not allowing it to spin freely. The drag from the binding brake probably caused the rotor to overheat and warp. Remember that a brake isn't intended to be engaged 100% of the time especially as you are riding -- only when you are stopping. Now what you need to figure out is why was the brake binding. That's your root cause issue with the warped rotor. Good luck.

Kent

[141987]

Hi,

I had a 2008 R1200GS, and I have a 2011 R1200GS, both of which I bought new, and both equipped with ABS, and I wouldn't say that the rear wheel ever spun completely freely on either of them. Rather there appears to be a slight brake drag. I have assumed that this is normal.

If I spin the rear wheel by hand the wheel would turn for a couple or three revolutions and then stop. But if I pushed the caliper pads away from the rotor it would spin much more freely.

I wonder if the drag that I have described on my bike isn't normal for a bike with ABS? Certainly the rear brake pads on my bike don't appear to wearing prematurely. Does your bike have ABS? If you spin the rear wheel on a new bike in the dealership I wonder how many times it would spin before it came to a stop.

[CarolinaRT]

It's normal, but enough drag to warp the rotor indicates binding.

My bike's previous owner warped the rear rotor in the first 2 years. He was a Harley rider and I suspect that he stopped mostly with the foot brake. I effected a 90% repair with a large blunt object.

[klumbsh1]

It's normal, but enough drag to warp the rotor indicates binding.

My bike's previous owner warped the rear rotor in the first 2 years. He was a Harley rider and I suspect that he stopped mostly with the foot brake. I effected a 90% repair with a large blunt object.

NICE!

Inner pad drag is the norm, it can warp over time if you are excessive with the rear brake.

To the OP, at 30K KM check,clean, grease the sliders, replace the rotor from beemerboneyard or someplace similar and forget about it.

[henzilla]

He was a Harley rider and I suspect that he stopped mostly with the foot brake. I effected a 90% repair with a large blunt object.

Even when you only use the front lever...the rear is activated....every time. The rear is independent from the front.

I came off a HD and had more of an issue with a size 11 boot hitting that little pedal.

[MPMARTY]

And some folks just need a place to rest their toes. That foot brake lever is handy and will warp a disk in very short order.

[deilenberger]

As Paul suggested (and yes - it's a floating caliper, not a design I particularly like) - the pins the caliper slides on are likely binding. Yours sounds like an extreme case, but LOTS of hexheads have a rear brake drag that's enough to really heat the rear rotor up, hot enough to burn you - even with no braking.

Cure is - remove the caliper - slide it back and forth on the pins. It loosens up. If it doesn't loosen up, you'll have to get under the little accordion boots to grease the pins with some high temperature grease. Whoever is supposed to be greasing these at the factory must go on break a lot..

[Fat Bear]

Thank you everyone for your helpful advice. New rotor / bolts installed and caliper cleaning done. So far, so good - only time will tell if the cleaning was the fix for sure. This is the first time that I've posted a tech issue on the forum and I sincerely appreciate the responses that I've received. Happy Trails,

[roamingbeemer]

Thanks guys,

I am adding the pins to my list of things to clean and lube occassionally.

[lkraus]

As Paul suggested (and yes - it's a floating caliper, not a design I particularly like) - the pins the caliper slides on are likely binding. Yours sounds like an extreme case, but LOTS of hexheads have a rear brake drag that's enough to really heat the rear rotor up, hot enough to burn you - even with no braking.

Cure is - remove the caliper - slide it back and forth on the pins. It loosens up. If it doesn't loosen up, you'll have to get under the little accordion boots to grease the pins with some high temperature grease. Whoever is supposed to be greasing these at the factory must go on break a lot..

My '06 RT seems to have more than it's fair share of rear brake drag. If I start up cold, ride a half mile down the road at 40mph and coast to a stop, my infrared thermometer says the rear disc is at 180??F, while the front discs are still at ambient temp. I'm still experimenting with solutions. Two different caliper greases, and new caliper seals have not helped.

But I've come to believe that it is easy to OVER grease the caliper pins. The pin sliding into its housing is basically a piston in a cylinder. The air in the housing needs somewhere to move to when the pin moves. The pin has a couple flats on its side for this purpose (I'm assuming), but if that space is filled with grease, air cannot move through and the caliper will not slide freely.

I'm currently trying a dry spray-on moly on the pins. It has helped some, but the sound alone tells me the drag is much more than BOTH front discs. I'm tempted to try a short run with the rubber pin boots removed. If that cures the drag, I'll try a small hole in the boots to allow the air to vent.

[racer7]

Those are interesting observations. If they apply to others' bikes, it might be part of the explanation for the shorter rear pad life as well. 180 is, of course, not very hot in terms of brake bits, in fact barely warm, but the persistent amount of difference is interesting.

Did you check the reservoir height and bellows position to see if it contributes to some of this?

Will be curious about your ultimate conclusions...