R12RT brake judder....again!

[gadgetgaz]

Already had the front and rear brake discs changed under warranty because of the judder and vibration when braking. Front discs at 2000miles and rear disc at 3500miles.

Now, at 4600miles, the problem is back again. This is really annoying me now. It's going back to the dealer as soon as they open after the weekend but, in the meantime, can this be due to anything other than warped discs?

[JohnJC]

Yes. The rotors can form an un-even glazing that can give a similar judder. Also, as in the case with my Multistrada, there can be a design flaw that causes a resonance frequence to build in the forks.

 

How are you bedding in the rotors/pads? This is important, can cause warping or uneven glazing. Not allowing your rotors to cool have hard braking can cause uneven buildup.

 

Just some thoughts.

[Steve1962]

Any news yet ?

 

Steve

[George]

Gutted for you Gaz, you spend so long at the dealers,you will soon be invited to their Christmas Party

 

Let us know the outcome

[BereIsland]

Sorry to here of your judder, must be bad luck,

 

Steve Carter

[gadgetgaz]

Steve, George and Steve, I have dumped the bike at Rainbow and told them I will pick it up when they have cured it. They didn't even argue just ordered new front discs.

These will be the 3rd front discs the bike has had (in addition to two rear discs). The front discs were changed at 2000 miles and 4800 miles and rear disc at 3000 miles.

They tell me that it is just down to poor quality steel. They seemed to have the attitude of "just keep bringing it back and we'll keep changing them until they (BMW) get the message." Which is fair enough I suppose. Apart from the inconvenience it's all done under warranty so it's not costing me anything. Besides, I have an F650 GS to play with which is a HOOT!

[Steve1962]

That must all be from a bad batch of metal then - how frustrating .

As long as they sort it , and you hadn't planned to use the bike for a holiday , I suppose you don't really have any option but to leave it with them .

I count myself lucky not to have encountered this problem .

Here's hoping you get your bike back real soon , properly mended !!

 

Steve

[gadgetgaz]

I got the bike back yesterday and it is fully sorted. After a brief go at deciding whether it could be something other than warped discs they replaced the front discs. This is now the third pair of front discs, hopefully they will last much longer this time!

[David]

I wonder if the problem could be improper installation, like innappropriate torque values.

[tickle_my_tummy]

I took my RT on a track day last week and noticed the judder happened during heavy braking.

 

It hadn't happened prior to the track day, and each bike can be different etc., but once I got through the juddering as I needed to slow down for the bends , the juddering seemed to disappear. IMHO I think this might be an issue with the pads rather than the discs?

[gadgetgaz]

Hmmm, well they swapped my front wheel onto their demo bike and the fault was swapped across and mine was OK.

Bearing in mind that the original discs fitted at the factory AND the second pair that were fitted at my dealers warped it is unlikely that it was due to inproper fitting.

I also had to have my back disc replaced, remember from an earlier posting? I think it is just down to poor quality steel.

[BMT]

Different bike, but my brakes were juddering towards the end of the warranty and I duly advised the dealer. He said it was not excessive, but noted it on the bike history in case of future difficulties. Over the next few thousand miles it became progressively worse and it was booked in for rectification.

 

Coincidentally, a few days before the dealer appointment, I changed the tyres and took the wheels-off opportunity to clean the grime off with a proprietory wheel cleaner.

 

Everything bright and clean, including the discs and their drillings -- judder disappeared. Now, I know that the wheel removal involved disturbing the calipers and pads, but I wouldn't be surprised if there is some effect on the braking performance if there is a lot of brake dust in the area.

 

Just my experience. The wheel cleaning has been effective on two occasions when juddering has become evident.

 

Have you or the dealer ever measured the run-out on suspect discs?

[gadgetgaz]

Checking the run-out is the second thing they do after test riding. I didn't ask what the run0off was on the first set off front discs.

The back brake (the dealer couldn't detect any juddering and said the bike rode well) turned out to be 0.2mm run-out and 0.1mm is allowed.

The recent front discs were within BMW's tollerences but the dealer said the new discs cured the problem so they changed them anyway

[big-t]

Everything bright and clean, including the discs and their drillings -- judder disappeared. Now, I know that the wheel removal involved disturbing the calipers and pads, but I wouldn't be surprised if there is some effect on the braking performance if there is a lot of brake dust in the area.

 

 

I have seen this happen in the automotive sector.The braking surfaces are at their best after a miniscule amount of friction material transfers to the rotor during the bedding in process.Ocassionally a rotor does not accept the friction material evenly all the way around and that results in the brakes grabbing and causing a vibration or judder when they hit the part of the rotor that has accepted the friction material.I have no idea whether the problem comes from the material in the rotor or the friction material,but the cure usually is to clean the rotor and replace the pads with a different mfgs pads.

 

That might be an option if the current set of rotors do not solve the problem,maybe they ought to clean the rotors and try a new set of pads,after 3 sets of rotors I would take a different approach.

[Geraldh]

I searched on 'judder' and can't find out what it means.

 

What exactly is 'judder'

[gadgetgaz]

JUDDER

 

"to shake or vibrate rapidly and intensively"

"To shake rapidly or spasmodically; vibrate conspicuously:"

[apm]

I know this is an old thread, but the problem is fairly new to me.

The Shuddering/Juddering has been progressively getting worse, and after a recent 2500km trip it is now constant at anything over 100kph and worse from higher speeds.I note that at low speed the problem doesn't exist.

I called the BMW dealer and he said that he had not heard of this problem before....I'll see what happens when I take the bike in to them next week.

Is anybody else having similar issues and if so, what are the fixes please.

 

Tony.

[skinny]

I'm having the same problem that started at about 8000 miles. I've checked the discs for run-out, checked the wheel and even replaced the pads. My next move will be to try lightly sanding the discs and see if they're glazed, but after that, I'll have to make a 700 mile round trip to my dealer (which I've been trying to avoid). I'm hoping I can convince the dealer to have a new set of discs in stock so that I don't have to make 2 trips.

[Dave Grinsel]

I have 8500 miles on my ST and have noticed the same problem. The shudder only appears during high speed, high effort braking. At slow speeds, the bike brakes smoothly.

[skinny]

I have 8500 miles on my ST and have noticed the same problem. The shudder only appears during high speed, high effort braking. At slow speeds, the bike brakes smoothly.

 

Same with mine...and it varies from a minor, but noticeable vibration to "oh shit, the %#*? wheel is coming off!" I'm hoping a good de-glazing will fix the problem.