2005-2009 R1200RT front end shudder

[nrfdmd]

I am one of the many RT owners who have experienced the front end shudder that has frequently been discussed here. I own a 2005 R1200RT with 44,000 miles. The first owner replaced the front rotors once and I have done it twice. Based on those discussions I purchased a new front wheel from a 2009 RT and installed it with my most recent set of rotors since I apparently had one of the bad batch of front wheels. Since others have had this problem and taken a similar course of action I would love to hear some follow-up on whether it fixed the problem long term. It seems fine now but I just completed those repairs and when just the rotors were replaced it seemed fine for the first thousand miles and then recurred as badly as it was originally.

[dirtrider]

Afternoon nrfdmd

 

On the 05 BMW 1200RT two things usually cause front end shutter/judder during braking.

 

One is brake rotor to wheel mounting issues (can be rotor mounting itself or wheel rotor mounting boss height discrepancies)

 

The other is brake pad deposits onto the hot brake rotors.

 

The first is usually cured by the new brake rotor mounting parts OR a new front wheel. (I have also machined the wheel brake rotor bosses to be ALL the same height to cure the braking judder issues) -- Or just spin the wheel on a static wheel balancer with a dial indicator set to indicate on the rotor mounting bosses as a quick check)

 

On the brake pad disposition problem-- That is difficult to find & define but is usually caused by very heavy braking therefore heating the brake rotors THEN quickly sitting a stop with red hot brake rotors & the brakes clamped on hard (brake pad material deposits-on & bakes-to the brake rotor)

 

Some aftermarket brake pads are very good at depositing brake pad material on hot brake rotors (OEM pads are usually durability tested by the MoCo to not do this)

 

As a rule this brake pad disposition is very thin & can't be seen or easily measured but it doesn't take much to change the braking friction as the pads cross the disposition area during braking (therefore judder)

 

On later non-servo brake systems you can sometimes tell the difference as wheel mounting issues or brake rotor mounting issues show up as a pulsation in the front hand brake lever whereas brake pad disposition will give you judder but no lever pulsation. On the servo (I-ABS) systems the servos dampen the braking enough that is can be very difficult to tell the difference.

[nrfdmd]

Thank you for your response. Since you seem so knowledgeable about this issue let me ask you some additional questions. My last set of rotors were installed at Morton's BMW and they placed a number of shims between the rotors and wheel to try to compensate for the discrepancies in the wheel but the problem returned. Having now replaced the wheel with one from a 2009 RT as well as installing new BMW rotors simultaneously do you think I can count on the problem being fixed long term?

[dirtrider]

Thank you for your response. Since you seem so knowledgeable about this issue let me ask you some additional questions. My last set of rotors were installed at Morton's BMW and they placed a number of shims between the rotors and wheel to try to compensate for the discrepancies in the wheel but the problem returned. Having now replaced the wheel with one from a 2009 RT as well as installing new BMW rotors simultaneously do you think I can count on the problem being fixed long term?

 

Afternoon nrfdmd

 

That depends-- On what was/is causing the problem. If your initial brake judder issue was caused by the wheel rotor mounting bosses being out of plane then it is probably good to go for ever.

 

On the other hand, IF your problem was caused by brake pad disposition & you are still using the same brake pads then it might come back after a couple of very hard stops then sitting with your brakes held on. (personally I never sit with the brakes held on after a very hard stop from speed on ANY vehicle I ride or own)

[nrfdmd]

Yes, my mechanic who is a BMW certified mechanic now working independently is his own shop measured my original wheel and confirmed that the rotor mounting bosses were out of plane and that on the new wheel that I purchased and installed they are perfectly in plane so hopefully that should solve the problem. However he did express some reservations about the engineering of the entire disk brake system of this model year and the next few years. Perhaps that is part of why it was redesigned for the 2010 model year.

[dirtrider]

Morning nrfdmd

 

 

The 1200RT brake system was actually re-designed for late 2006 & up.

 

To get a fast cycle ABS system on your 2005RT BMW used the servo apply ABS system. The servos supplied the needed make-up fluid during a prolonged ABS stop as well as significantly increasing the ABS cycled speed.

 

By late 2006 BMW had a new ABS system developed that was as fast or faster response then your present I-ABS & used internal accumulation for front prolonged ABS events & used rear servo pump for both ABS make-up fluid & for normal braking on the rear when using the front hand lever only. (I-ABS Gen2)

 

Neither your early I-ABS or later I-ABS Gen2 had any effect on the front brake pulsation on the early 1200RT's as that (brake pulsation) was due to brake rotor to wheel mounting issues and/or front wheel mis-machining of the wheel brake rotor attachment bosses. (ie if new front brake rotor mounting package didn't cure the brake pulsation then a new front wheel usually would)

 

[1NOTRED]

I bought a 2006 1200RT back in 2008 with 36K miles. It had been sitting for more than 3 months. It had front brake shudder, but a check showed no disc wobble.

 

With perseverance, I continued riding. After about 10K miles, the judder had disappeared, with no ill affects.

 

I believe it was caused by interaction between the pad and un-moved discs, which was un-noticeable.

[dirtrider]

Morning Yellowknife

 

Yes, that is called rotor staining & is caused by either damp brake pads at parking or from metallic pads oxidizing the rotor in the spots that they sit at. (never long park a disk brake vehicle after washing the vehicle without riding & drying the brakes first)

 

In most cases the staining will be so light that you can't see or measure it, it doesn't effect rotor thickness but does effect the brake pad to rotor friction as the pads pass over the stained areas.

[Dave_zoom_zoom]

Morning Yellowknife

 

Yes, that is called rotor staining & is caused by either damp brake pads at parking or from metallic pads oxidizing the rotor in the spots that they sit at. (never long park a disk brake vehicle after washing the vehicle without riding & drying the brakes first)

 

In most cases the staining will be so light that you can't see or measure it, it doesn't effect rotor thickness but does effect the brake pad to rotor friction as the pads pass over the stained areas.

 

Good Morning DR

 

Ahh yes! I think what you describe is a condition that has been experienced by many and understood by few. In your experience, can this be cured by careful application with a crocus cloth on a flat wooden block or perhaps a fine steel wool?

 

Thanks!

 

Dave

[dirtrider]

Afternoon Dave

 

Maybe, it depends on how deep the staining goes & how sensitive the vehicle is to brake disturbance (it's sure worth a try anyhow)--Crocus cloth is probably not aggressive enough to do much though. I usually start with Red Scotch pads & brake clean first & if that doesn't work then try a fine sandpaper, if still having brake disturbance issues then into my glass bead cabinet.

 

I have had some vehicles (like Ducati) that I have needed to actually glass bead the rotors to remove brake disturbance staining issues. (Ducati is very sensitive to any brake friction fluctuation)

 

 

[Dave_zoom_zoom]

Thank You DR!

 

Dave

[MSmith]

I have the same model year and problem that you experienced. After multiple rotor replacements (some under warranty) and an attempted shim job on the front wheel by the dealer, the front end judder always returned. Finally I replaced the front wheel and rotors from a 2010 model year. Consequently I also had to replace the front calipers due to a model year offset change. I'm happy to report no problems in 2 years 20K miles.

 

I think it stinks that the dealer didn't take care of this when I first reported the problem. Ultimately they spent more on rotors/pad replacement during the warranty period than if they had replaced the wheel. The experience caused me to change dealerships.

 

 

[dirtrider]

I have the same model year and problem that you experienced. After multiple rotor replacements (some under warranty) and an attempted shim job on the front wheel by the dealer, the front end judder always returned. Finally I replaced the front wheel and rotors from a 2010 model year. Consequently I also had to replace the front calipers due to a model year offset change. I'm happy to report no problems in 2 years 20K miles.

 

 

Morning MSmith

 

Did you put the correct early ABS tone ring on that wheel with the later rotors?

[MSmith]

Hi DR...forgot about that. Yes, I used the ABS ring from my original wheel. So far so good.

[dirtrider]

Morning MSmith

 

 

If you can find a machine shop in you area that has a "gap-bed" (large swing) lathe then your original wheel can have the rotor mounting pads machined to be on the same plane & that wheel will be good to go again (nothing wrong with the wheel it's those pesky rotor mounting pads being hi & low).