[RonHolly]

DanDiver and I looked at my rear rotor, about a month ago, and discovered the rear rotor was loose. After taking a close look it seems like it was made to be loose. It does make a lot of noise when hitting any small bump in the road. When applying rear brake no more noise. Is it supposed to be that noisy?

 

[katnapinn]

It is made to "float" some but if it is noisy then it is too loose. Replace it with an EBC rotor & you be good to go.

 

[deputy5211]

DanDiver and I looked at my rear rotor, about a month ago, and discovered the rear rotor was loose. After taking a close look it seems like it was made to be loose. It does make a lot of noise when hitting any small bump in the road. When applying rear brake no more noise. Is it supposed to be that noisy?

That "cow bell" feature is part of why the LT costs what it does. You can replace it with an EBC rotor as I ad many others did, but you are likely to piss off some german engineer(s) and that is probably not a good thing. After all, they designed it so you can ride your fancy BMW motorbike and have people look at you like you are on a rickety P.O.S. from all of the noise it makes. Same reason the brakes squeal until you replace them with EBC pads and bed them in good.

:histerica

 

[PMitchell]

That "cow bell" feature is part of why the LT costs what it does. You can replace it with an EBC rotor as I ad many others did, but you are likely to piss off some german engineer(s) and that is probably not a good thing. After all, they designed it so you can ride your fancy BMW motorbike and have people look at you like you are on a rickety P.O.S. from all of the noise it makes. Same reason the brakes squeal until you replace them with EBC pads and bed them in good.

:histerica

+1 and lots of threads on how to do it. beemerboneyard has them and use BMWMOA for a 10% discount :wave

 

[K100Dennis]

What wears to cause the looseness ? I haven't had mine off yet, it's still silent but there is looseness there, obviously not enough. I'm wondering if liquid polyeurethane can be poured into the voids to take up the slack (around tyhe floating bushes). My disc is still like new (thickness) and brakes are fine so it's a shame to waste the disc. Thoughts ?

 

[BecketMa]

Here is an oldie but goodie:
http://www.bmwlt.com/forums/showthread.php?t=3319&highlight=Floating+rotor

The stock front pads were about twice the price of EBC. So, I use EBC front and back.

Withthe audio cranked up so that I can hear it thru my helmet and using ear plugs on the open road, I nevr hear the rear rotor rattle.

Best from tucson
Bob

 

[mwnahas]

Just for the record, I replaced my rear break pads with BMW pads and got rid of the school busl and had the rotor replaced with a BMW rotor over 30k miles ago, been quiet ever since. When you buy the new rotor, whichever one you choose get new bolts too.

 

[STEBS]

I just replaced mine with the ebc pro lite rotor and ebc pads for $161.00, no more noise and seems to be better braking, you don't need to change the two bolts that hold it on, they just hold it in place when the wheel is removed, the five lugs do all the work.

EBC Pro-Lite Brake Rotor - Rear MD615 = $131.01

Amazon was the cheapest I found.

It's an easy fix with a little heat from a torch or heat gun.

 

[westvandude]

Well, being new to the LT glad to hear this is normal. I got a helluva racket every time I apply the brakes. Sounds like the pads in the rear caliper are slapping around loose or a sound like the caliper bolts were loose.

Squeal from hell too. Anyhow, I pulled the caliper off, all bolts were tight. I applied Wurth Anti-Squeal spray to the rear of the pads. Then put them back in and re-mounted the caliper. Then I was playing around with the rotor... all loosy-goosy and I'm thinking what the heck? Now I read here it's normal. Well the "bolts" that hold the rotor surface onto the rest of the rotor hub look like big rivets no way to tighten them... the whole floating rotor thing. I'm wondering if this is my clackety clack noise when I hit rear brakes at a stop light while going real slow.

Hopefully the wurth spray fixes most of my squeal issue. I'm gonna spray that stuff on the front brake pads as well next fix-it-session.

I left the rear wheel off, gonna replace the tire this week, have a new one on the way.

 

[RonHolly]

Well, being new to the LT glad to hear this is normal. I got a helluva racket every time I apply the brakes. Sounds like the pads in the rear caliper are slapping around loose or a sound like the caliper bolts were loose.

Squeal from hell too. Anyhow, I pulled the caliper off, all bolts were tight. I applied Wurth Anti-Squeal spray to the rear of the pads. Then put them back in and re-mounted the caliper. Then I was playing around with the rotor... all loosy-goosy and I'm thinking what the heck? Now I read here it's normal. Well the "bolts" that hold the rotor surface onto the rest of the rotor hub look like big rivets no way to tighten them... the whole floating rotor thing. I'm wondering if this is my clackety clack noise when I hit rear brakes at a stop light while going real slow.

Hopefully the wurth spray fixes most of my squeal issue. I'm gonna spray that stuff on the front brake pads as well next fix-it-session.

I left the rear wheel off, gonna replace the tire this week, have a new one on the way.

Your rotor is worn out. Due to poor design of the rotor they have early failure and the only thing to do is replace it. Not cheap to do but about the only "real" fix for it. You could try and "jerry rig" with replacing two or three rivets with bolts to tighten things up. I elected to replace my rotor and new pads and haven't had a problem since. Let us know what you do to yours and how it worked out. To see how it was made I removed the inner hub from the rotor and it's more than just rivets. I post pic when I get a chance.

You can see the wear on this "special" rivet. There is/was a spring wire going around the rivet's circumference that is worn away that is supposed to provide a cushioning effect. You can also see, on the disk, where the rivet has wallowed out cutout and this is what's causing all the clanking!

 

[RonHolly]

I bought the EBC rotor disc and brake pads from BMW Bone Yard for $228 delivered. Wish I had bought better pads so there's not so much dust on the rims.

 

[deputy5211]

Your rotor is worn out. Due to poor design of the rotor they have early failure and the only thing to do is replace it.

I respectfully disagree with the basis of that conclusion. The best way to tell if the rotor is "worn out" is to take a caliper to it. Another way to tell if a rotor replacement is required is to check for warping. I did not see any measurements posted about either of these factors.

That the floating rear rotor developed the beloved "cow bell" syndrome is NOT, on its own, evidence of the rotor wearing out. Cow bell IS annoying, even a bit disconcerting until one realizes what the problem is, but it does not necessarily indicate a worn out rotor.

 

[RonHolly]

I respectfully disagree with the basis of that conclusion. The best way to tell if the rotor is "worn out" is to take a caliper to it. Another way to tell if a rotor replacement is required is to check for warping. I did not see any measurements posted about either of these factors.

That the floating rear rotor developed the beloved "cow bell" syndrome is NOT, on its own, evidence of the rotor wearing out. Cow bell IS annoying, even a bit disconcerting until one realizes what the problem is, but it does not necessarily indicate a worn out rotor.

Here's what he has already identified, "Then I was playing around with the rotor... all loosy-goosy and I'm thinking what the heck? " I guess we will see what the problem was when he get's it all figured out and repaired. Loosy-Goosy means worn rivets.

 

[westvandude]

By loosy goosy I mean about 1-2mm play. In my experience with Japanese bikes the rotors are tight. So I was kinda freaked out by this. Don't get me wrong, it doesn't seem like anything is falling off (the rotor) just seems odd to me. All the rivet pins are in place, none are missing or look like they are falling out.

Probably just going to run with it this next season and check it a couple times during the year to see it's not getting worse.

 

[RonHolly]

I just replaced mine with the ebc pro lite rotor and ebc pads for $161.00, no more noise and seems to be better braking, you don't need to change the two bolts that hold it on, they just hold it in place when the wheel is removed, the five lugs do all the work.
EBC Pro-Lite Brake Rotor - Rear MD615 = $131.01 Amazon was the cheapest I found. It's an easy fix with a little heat from a torch or heat gun.

I wish I could have found the Amazon deal you found when I was looking. I checked everywhere I could research including Amazon and Boneyard was the best I could find at the time July '12.

 

[deputy5211]

Here's what he has already identified, "Then I was playing around with the rotor... all loosy-goosy and I'm thinking what the heck? " I guess we will see what the problem was when he get's it all figured out and repaired. Loosy-Goosy means worn rivets..

Yes, but the very next sentences were: "Now I read here it's normal. Well the "bolts" that hold the rotor surface onto the rest of the rotor hub look like big rivets no way to tighten them... the whole floating rotor thing."

"Loosey Goosey" is the floating rotor floating, albeit more than one might prefer. There are many forum posts on this being annoying but not generally negatively impacting braking performance or safety.

"Worn" is quite different than "worn out." For example: The boots I bought last month are "worn" but it will be years before they are worn out.

FWIW, I replaced my factory rotor, which had developed the cow bell, with an EBC rotor because the clanging and rattling sounds were annoying and embarrassing. I did not need to replace it for any reason other than I wanted to get rid of one of the more annoying LT sounds. I still have that rotor in my garage as a spare, in case my EBC wears our or fails.

Just my $0.02. YMMV

 

[RonHolly]

By loosy goosy I mean about 1-2mm play. In my experience with Japanese bikes the rotors are tight. So I was kinda freaked out by this. Don't get me wrong, it doesn't seem like anything is falling off (the rotor) just seems odd to me. All the rivet pins are in place, none are missing or look like they are falling out.

Probably just going to run with it this next season and check it a couple times during the year to see it's not getting worse.

If it's loose "at all" it will make a noise everytime you hit a bump in the road. Shouldn't be able to move it by hand. Can't remember how many rivets are securing my rotor, 8 I think, but with that many it shouldn't move with your hand pressure. How many miles are on yours? When I bought my bike it had 36,500 miles on it and rotor was already worn out. Sooo embarrising when I would go down a brick road that I had to slightly press rear brake, under power, to keep noise down. Radio wouldn't hide it! LoL

Take a rubber headed mallet and slightly tap the rotor and see if it makes noise. Shouldn't be any "if" you don't like cow bells ringing. I agree that's it's not unsafe "but" who wants a Cadillac of the motorcycle industry sounding like a rattle trap. When I see rivet wear and excessive mating rotor wear it's not OK with me.

 

[deputy5211]

If it's loose "at all" it will make a noise everytime you hit a bump in the road. Shouldn't be able to move it by hand. Can't remember how many rivets are securing my rotor, 8 I think, but with that many it shouldn't move with your hand pressure. How many miles are on yours? When I bought my bike it had 36,500 miles on it and rotor was already worn out. Sooo embarrising when I would go down a brick road that I had to slightly press rear brake, under power, to keep noise down. Radio wouldn't hide it! LoL

Take a rubber headed mallet and slightly tap the rotor and see if it makes noise. Shouldn't be any "if" you don't like cow bells ringing. I agree that's it's not unsafe "but" who wants a Cadillac of the motorcycle industry sounding like a rattle trap. When I see rivet wear and excessive mating rotor wear it's not OK with me.

Nobody is disputing the embarrassing and annoying aspects of the cow bell. Those are the reasons I cited (above) for swapping mine for an EBC.

The sole point in dispute here is your stated conclusion that the rotor is worn out.

Oh, I also take exception to your calling our beloved (and cursed at the same time) LTs a Cadillac. To me, that just sounds silly because Cadillac does not summon up images of quality, precision, or status. On the other hand, neither does my LT.

:stir:

 

[RonKMiller]

The rear rotor on my '01 LT went 140K and was not even close to being worn out.

I think BMW has the absolute best brakes of any brand motorcycle I've ever owned. That even goes back to my '79 Airhead's ATE's - which by today's standards is like dragging your feet - but for it's time was simply amazing.

Oh yeah, there is NO SUCH THING as a "warped" rotor. Sorry.

http://www.stoptech.com/technical-support/technical-white-papers/-warped-brake-disc-and-other-myths

 

[deputy5211]

Oh yeah, there is NO SUCH THING as a "warped" rotor. Sorry.

http://www.stoptech.com/technical-support/technical-white-papers/-warped-brake-disc-and-other-myths

Even better, Ron! Does that leave just caliper measurement of the rotor disc as the sole technical measure of whether rotor is worn out?