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K75s floating brake rotors?
- Thread starter bmwrebel
- Start date
mieczkow
Tom Mieczkowski
Take a look at EBC's
Well, I'll make a recommendation based on my experience with my '87 k75S. I had real serious pulsing and squeaking that I couldn't remedy with new pads, wet-sanding the rotors, cleaning and re-cleaning, etc. No change. They were well within spec thickness-wise and they were not warped - I checked them with a dial gauge. But they squeaked like hell (which was annoying but not dangerous) but they also pulsed like hell (dangerous, in my view). I looked around and could not find anybody to re-surface them - apparently even if you're willing to mail them off someplace there are few or no shops who will surface grind the rotors. I couldn't get any place identified even asking on the forum. Seems the only places that will re-grind want so much money for the set-up charge that it is not practical to go that route. I also contacted Spiegler about their rotor swap (you send the old rotors, they remove the discs from the hubs and put new discs on - which they described as "semi-floating rotors") but it was expensive - about $200 a rotor. So I went with the EBC rotors and also used their copper-sintered pads. The swap was pretty easy to do and I have been very happy. Pulsing elminated, squeaking eliminated. I was so satisfied I also put an EBC on my rear brake. I've now got about 4k miles on them and they have held up very well.
Last time I posted on this topic I had a few folks who really blasted the rotors
- there are apparently people who think they are not too good. Some folks objected to my describing them as "full floating" which is how EBC describes them (my understanding - they move both medially and laterally relative to the hub). I don't want to get into a debate with anybody; I am basing this opinion on my experience with the rotors. I know there are fans of Braking (sp?) rotors which are discs you install on the original stock carrier hubs yourself after drilling off the old discs. I didn't really look at those so I am not at all knowledgeable about them. Some people like them based on what I have read on the forum, but bear in mind you have to drill out the old rivets on the hub (no big deal if you have a drill press available). I don't know of anyone who has used the Spiegler swap-outs. As I said, my experience with EBC has been so-far so-good.
Best of luck - if you are at all able to do moderate mechanical work you will find swapping the rotors to be pretty easy to do. If the improvement is anything like what I experienced, it's a real satisfying project.
Well, I'll make a recommendation based on my experience with my '87 k75S. I had real serious pulsing and squeaking that I couldn't remedy with new pads, wet-sanding the rotors, cleaning and re-cleaning, etc. No change. They were well within spec thickness-wise and they were not warped - I checked them with a dial gauge. But they squeaked like hell (which was annoying but not dangerous) but they also pulsed like hell (dangerous, in my view). I looked around and could not find anybody to re-surface them - apparently even if you're willing to mail them off someplace there are few or no shops who will surface grind the rotors. I couldn't get any place identified even asking on the forum. Seems the only places that will re-grind want so much money for the set-up charge that it is not practical to go that route. I also contacted Spiegler about their rotor swap (you send the old rotors, they remove the discs from the hubs and put new discs on - which they described as "semi-floating rotors") but it was expensive - about $200 a rotor. So I went with the EBC rotors and also used their copper-sintered pads. The swap was pretty easy to do and I have been very happy. Pulsing elminated, squeaking eliminated. I was so satisfied I also put an EBC on my rear brake. I've now got about 4k miles on them and they have held up very well.
Last time I posted on this topic I had a few folks who really blasted the rotors
- there are apparently people who think they are not too good. Some folks objected to my describing them as "full floating" which is how EBC describes them (my understanding - they move both medially and laterally relative to the hub). I don't want to get into a debate with anybody; I am basing this opinion on my experience with the rotors. I know there are fans of Braking (sp?) rotors which are discs you install on the original stock carrier hubs yourself after drilling off the old discs. I didn't really look at those so I am not at all knowledgeable about them. Some people like them based on what I have read on the forum, but bear in mind you have to drill out the old rivets on the hub (no big deal if you have a drill press available). I don't know of anyone who has used the Spiegler swap-outs. As I said, my experience with EBC has been so-far so-good.Best of luck - if you are at all able to do moderate mechanical work you will find swapping the rotors to be pretty easy to do. If the improvement is anything like what I experienced, it's a real satisfying project.
deilenberger
A bozo on the bus
I'd have to agree with Tom..
The S seems particularly prone to brake shudder. I'm more or less the poster boy for it on my old S..
On it - at various times - to fix the shudder, I did:
- Good used rotors - no visible wear. Worked great for about 8,000 miles and the shudder came back.
- Braking Rotors - Installed them myself on hubs that I checked for "true" - and they worked great for about 8,000 miles and the shudder came back.
- New wheel bearings - installed them, the shudder went away - for about 8,000 miles, then it came back. Did another set of bearings - the shudder remained.
I also at various times tried to find a way to resurface the rotors - stock and Braking - nothing worked. I had them surface ground - and the finish was too rough, and holding a large disk to +/- 0.001" parallelism isn't easy apparently. I also used special 3M sanding disks on some rotors - no change, and a flex-hone - no change. The problem isn't warping - it's a change in the actual surface of the disks.. more on this below.
- EBC rotors and pads - bought these. The rotors are NOT stainless steel. If left out in the rain overnight, you will see some surface rust form. These are still on the bike (a friend bought it) - and they have about 10k miles on them. Seems to be working fine.
OK - the more on what's happening. I believe - what is happening is a combination of things. Surface friction is an important factor in smooth braking. It seemed as if the BMW pads and rotors - if left with moisture between them (rain, or washing the bike) actually setup galvanic corrosion at the contact point (pad/rotor). It was noticeable as a discoloration of the rotor after this happened, and I believe it also changed the coefficient of friction at that spot. I don't think warping is a significant factor here - I used some fairly advanced techniques, and could never find an measurable warp on the rotors. I also suspect that as the wheel bearings wear - they can contribute to the problem... it's sorta small bad things stacking up to make one BIG bad thing - the shudder.
The reason I went EBC - it because they are NOT stainless. I actually contacted them and discussed this problem at length before purchasing them, and they assured me that this would not be a problem with their rotors.
It appears that it hasn't been a problem, but I'm not riding that bike anymore and I can't say what might happen in the future. The EBC was nice - it came assembled on carriers, so it was bolt it up and go ride. They're more expensive than the Braking rotors, less expensive by FAR than stock BMW rotors.
I'd recommend them..
The S seems particularly prone to brake shudder. I'm more or less the poster boy for it on my old S..
On it - at various times - to fix the shudder, I did:
- Good used rotors - no visible wear. Worked great for about 8,000 miles and the shudder came back.
- Braking Rotors - Installed them myself on hubs that I checked for "true" - and they worked great for about 8,000 miles and the shudder came back.
- New wheel bearings - installed them, the shudder went away - for about 8,000 miles, then it came back. Did another set of bearings - the shudder remained.
I also at various times tried to find a way to resurface the rotors - stock and Braking - nothing worked. I had them surface ground - and the finish was too rough, and holding a large disk to +/- 0.001" parallelism isn't easy apparently. I also used special 3M sanding disks on some rotors - no change, and a flex-hone - no change. The problem isn't warping - it's a change in the actual surface of the disks.. more on this below.
- EBC rotors and pads - bought these. The rotors are NOT stainless steel. If left out in the rain overnight, you will see some surface rust form. These are still on the bike (a friend bought it) - and they have about 10k miles on them. Seems to be working fine.
OK - the more on what's happening. I believe - what is happening is a combination of things. Surface friction is an important factor in smooth braking. It seemed as if the BMW pads and rotors - if left with moisture between them (rain, or washing the bike) actually setup galvanic corrosion at the contact point (pad/rotor). It was noticeable as a discoloration of the rotor after this happened, and I believe it also changed the coefficient of friction at that spot. I don't think warping is a significant factor here - I used some fairly advanced techniques, and could never find an measurable warp on the rotors. I also suspect that as the wheel bearings wear - they can contribute to the problem... it's sorta small bad things stacking up to make one BIG bad thing - the shudder.
The reason I went EBC - it because they are NOT stainless. I actually contacted them and discussed this problem at length before purchasing them, and they assured me that this would not be a problem with their rotors.
It appears that it hasn't been a problem, but I'm not riding that bike anymore and I can't say what might happen in the future. The EBC was nice - it came assembled on carriers, so it was bolt it up and go ride. They're more expensive than the Braking rotors, less expensive by FAR than stock BMW rotors.
I'd recommend them..
shakeybone
New member
I had EBC's on my Yamaha and was very happy with them both in breaking performance and eliminated the squeaking.
I have not yet put them on my K100 but will someday(maybe this winter).
I have not yet put them on my K100 but will someday(maybe this winter).
gregfeeler
Dances With Sheep
I have not used these myself, but know a number of people who have used the Brakking rotors and liked them. They are inexpensive relative to the EBC or stock rotors - my local cost is about $115/each. However, you will need to have a bench grinder to grind off the rivet heads holding your old rotors to the carriers. After than, just punch out the rivets with a punch and hammer, and bolt on the new rotors.
I've also talked with a number of people who have liked the EBC rotors as well. Personally, I want to keep the stock carries for the look, so see that as an advantage of the Brakkings.
As for pads, I think pretty highly of the EBC HH pads. Seem to bed in fast and grip really, really well.
I've also talked with a number of people who have liked the EBC rotors as well. Personally, I want to keep the stock carries for the look, so see that as an advantage of the Brakkings.
As for pads, I think pretty highly of the EBC HH pads. Seem to bed in fast and grip really, really well.
breyfogle
New member
When the stock front rotors on my K75S got down past their wear limit, I replaced them with EBC Pro-Lite floating rotors mainly for the cost savings, easy removal and replacement and the "cool" factor. Based on my experience, I would not recommend them to anyone.
First, they are only "floating style" rotors. Pro-lites are assembled to look like real floating rotors with separate a carrier and disk attached by bobbins. However, the bobbins are as tight as rivits so the rotors do not actually float. Also, the bobbins are not user replaceable, so when a disk wears down or the bobbins wear, the whole assembly must be replaced, just like OEM rotors.
More importantly, EBC's quality control needs improvement. My first set of Pro-Lite rotors never ran true ( way to much lateral run-out ) which quickly wore the disks into uneven an thickness which in turn produced both low speed pulsation which was annoying and high speed chatter which was down right dangerous. I found it interesting that EBC's own website talks about just such a problem in its FAQ section (which implies to me that the problems I had were not new or unusual to EBC). To their credit, EBC replaced the first set of rotors with a second set. This set is still on the bike. The lateral runout is still present but seems to be small enough to avoid rapid uneven wear (so far). I can feel some small amount of low speed pulsation but the chatter has not (yet) returned.
My bottom line, EBC rotors are inexpensive and you get what you pay for.
YMMV.....
First, they are only "floating style" rotors. Pro-lites are assembled to look like real floating rotors with separate a carrier and disk attached by bobbins. However, the bobbins are as tight as rivits so the rotors do not actually float. Also, the bobbins are not user replaceable, so when a disk wears down or the bobbins wear, the whole assembly must be replaced, just like OEM rotors.
More importantly, EBC's quality control needs improvement. My first set of Pro-Lite rotors never ran true ( way to much lateral run-out ) which quickly wore the disks into uneven an thickness which in turn produced both low speed pulsation which was annoying and high speed chatter which was down right dangerous. I found it interesting that EBC's own website talks about just such a problem in its FAQ section (which implies to me that the problems I had were not new or unusual to EBC). To their credit, EBC replaced the first set of rotors with a second set. This set is still on the bike. The lateral runout is still present but seems to be small enough to avoid rapid uneven wear (so far). I can feel some small amount of low speed pulsation but the chatter has not (yet) returned.
My bottom line, EBC rotors are inexpensive and you get what you pay for.
YMMV.....
