Need replacement front rotors for R1100RT

[Luky]

2000 R1100RT, ~81k miles, original owner.  I had replaced the front rotors years ago with EBC pro-lites due to wear.  I don't ride much anymore (about 4k miles in last 5 years) but am now getting some pulsing in the front brakes when braking and also have a lot of rattling when going over bumps so I think the bobbins are shot too.  I ordered new Bobbins from Moto-bins (and a new rear rotor just because I'm bored and mine is still original), however I had forgotten I had removed the stock rotors and I'm not sure the new bobbins will work on the EBC rotors so I will probably sell them in the classifieds.

 

Due to the pulsing and reading some other threads (it seems this is likely due to sitting for long periods and the pads corroding the surfaces, and is difficult to clean up on the rotor surfaces), I am looking for some new rotors that won't break the bank.  

 

BMW PN's from From Realoem:

Left - 34512310816

Right - 34112310484

 

I am looking for suggestions/recommendations for new aftermarket front rotors, for cast wheels and ABS. 

 

I found these Niche Industries for only $154 pair which seems super low cost.  https://nicheindustries.com/products/niche-519-crt2388r-2pack?variant=42425406390463

 

I also found a set of Arashi rotors on Amazon for $196 https://www.amazon.com/gp/product/B07M5T6VNY/ref=ox_sc_act_title_2?smid=A734PUKJT4INA&psc=1

 

If anyone has experience with either of these brands I would appreciate hearing from you.  Not finding much online about them.  If you know where I can get some decent replacements for much less than ~$500 for a set, please point me in that direction.  Recently got a bug to ride more and replaced the battery, flushed the engine oil three times (started with liquid moly engine flush which I saw very little if any gunk come out), trans and final drive.  I will do the brake fluid too, once I get the new rotors to install. 

 

Thanks,

[dirtrider]

31 minutes ago, Luky said:

2000 R1100RT, ~81k miles, original owner.  I had replaced the front rotors years ago with EBC pro-lites due to wear.  I don't ride much anymore (about 4k miles in last 5 years) but am now getting some pulsing in the front brakes when braking and also have a lot of rattling when going over bumps so I think the bobbins are shot too.  I ordered new Bobbins from Moto-bins (and a new rear rotor just because I'm bored and mine is still original), however I had forgotten I had removed the stock rotors and I'm not sure the new bobbins will work on the EBC rotors so I will probably sell them in the classifieds.

 

Due to the pulsing and reading some other threads (it seems this is likely due to sitting for long periods and the pads corroding the surfaces, and is difficult to clean up on the rotor surfaces), I am looking for some new rotors that won't break the bank.  

 

BMW PN's from From Realoem:

Left - 34512310816

Right - 34112310484

 

I am looking for suggestions/recommendations for new aftermarket front rotors, for cast wheels and ABS. 

 

I found these Niche Industries for only $154 pair which seems super low cost.  https://nicheindustries.com/products/niche-519-crt2388r-2pack?variant=42425406390463

 

I also found a set of Arashi rotors on Amazon for $196 https://www.amazon.com/gp/product/B07M5T6VNY/ref=ox_sc_act_title_2?smid=A734PUKJT4INA&psc=1

 

If anyone has experience with either of these brands I would appreciate hearing from you.  Not finding much online about them.  If you know where I can get some decent replacements for much less than ~$500 for a set, please point me in that direction.  Recently got a bug to ride more and replaced the battery, flushed the engine oil three times (started with liquid moly engine flush which I saw very little if any gunk come out), trans and final drive.  I will do the brake fluid too, once I get the new rotors to install. 

 

Thanks,

I can't help you on cheap rotors but if your EBC rotors are still in good shape then you can probably save them . 

 

Sometimes a good cleaning using brake clean & a Scotch pad can help but if the rotor staining is fairly bad or deep that probably won't be enough. 

 

If you have a good metal prep shop near by with a blasting cabinet  then you can remove your rotors, mask them off, then see if you can find a shop that will blast them with baking soda (NOT SAND OR GLASS BEADS). 

 

I have used very/very/very worn glass beads to remove the staining from a few brake rotors but I know the condition of my blasting media & use a very low air pressure at a distance. If the blasting media is too aggressive it leaves a rough surface that will just eat brake pads for dinner. Baking Soda is the safe bet if having others do the blasting. 

 

You can also sometimes save stained rotors by wet sanding with 400 grit wet & dry (do it wet) then a final sanding with 500 wet & dry (again do it wet). Make sure the sanding is done with a solid sanding block, even a hard rubber block will work but do not use anything soft or not flat. Keep the sanding moving so as not to do one spot  more than the other spots. 

 

I have also heard (never tried it myself) that coating the brake rotors with aggressive (cheap) toothpaste then doing some light stops can remove or reduce staining caused pulsation. Cheap toothpaste is probably just aggressive enough for this but I haven't any experience in doing it that way as I have a commercial sized blasting cabinet with lots of very well used glass beads. I do have  blasting baking soda but that stuff is a pain to get back out of my blast cabinet so I only use that  for putting  a satin finish on antique alloy carburetors.  

[Luky]

Hi DR,

 

I just measured them with calipers and it looks like 4.93/4.95mm thick on the wear surfaces, and I can definitely see some smeared discoloration on the surfaces. I think I had read 4.5mm thick was the minimum for front rotors (so potentially lots of life left)?  My maintenance log shows I installed the EBC rotors 5/12/2007 with 68,697 miles, so only about 12k (local) miles on them.  My other concern is the front rattling I get over bumps/curbs (I'm assuming the bobbins are shot).  I'll give them a scotch brite scrub and see if that helps with the pulsing.

 

I am inclined to get a "cheap" set of rotors to install and see if I can disassemble the EBC's and "refurbish" them based on your feedback.  I could probably try to disassemble the rings and wet sand them on a sheet of tempered glass to make sure it is a flat surface, although the "wear" surface may be too recessed for this to work.  I have a friend with a blasting cabinet (used it to clean up some old car calipers before) but I may hesitate at this as it sounds easy to screw them up...

[Michaelr11]

1 hour ago, Luky said:

am inclined to get a "cheap" set of rotors to install and see if I can disassemble the EBC's and "refurbish" them

I have had great success buying OEM rotors from bike breakers.  I have been insistent about getting rotor thickness measurements and assurance that they are flat. If not what was offered, they can be returned. I’ve gotten perfectly good rotors, generally with at least 75% of thickness available. I don’t think I ever paid more than $150.  Haven’t looked for a set in a while so I don’t know what is available.

 

[Luky]

I was just looking for info to see if I could get new bobbins for the EBC rotors/carriers if they are a different size from BMW ones, and ran across several youtube videos about how to check/clean the bobbins to make sure they are free spinning and it can eliminate brake judder is some cases.  I think I am going to give this a try as it is basically free with stuff I already have in my garage.  I know that I have never checked or tried to "service" the bobbins before.

 

 

[King Herald]

6 hours ago, Luky said:

I was just looking for info to see if I could get new bobbins for the EBC rotors/carriers if they are a different size from BMW ones, and ran across several youtube videos about how to check/clean the bobbins to make sure they are free spinning and it can eliminate brake judder is some cases.  I think I am going to give this a try as it is basically free with stuff I already have in my garage.  I know that I have never checked or tried to "service" the bobbins before.

 

 

Don’t do that! The bobbins are aluminium and once you start spinning them they wear down very quickly and rattle. Ask me how I know.

I replaced mine with stainless 6 years ago. They are only there to allow thermal expansion of the disc so don’t need to have any play in them. 

[Luky]

On 4/23/2024 at 5:10 PM, Michaelr11 said:

I have had great success buying OEM rotors from bike breakers.  I have been insistent about getting rotor thickness measurements and assurance that they are flat. If not what was offered, they can be returned. I’ve gotten perfectly good rotors, generally with at least 75% of thickness available. I don’t think I ever paid more than $150.  Haven’t looked for a set in a while so I don’t know what is available.

 

Do you have any suggested "bike breakers" where I can search?  I checked beemer boneyard and they have a set that is about 50% worn for $225. They say "non-ABS" but I assume I can just add my ABS sensor ring to them? $225 seems a lot for 50% worn out and rough shape from the pic...

[Michaelr11]

1 hour ago, Luky said:

Do you have any suggested "bike breakers" where I can search?  I checked beemer boneyard and they have a set that is about 50% worn for $225. They say "non-ABS" but I assume I can just add my ABS sensor ring to them? $225 seems a lot for 50% worn out and rough shape from the pic...

 

Put the BMW part number, without spaces, into the eBay search box. I put the right ABS rotor in, 34 11 2 310 484, and got many results. They went from $200 to under $100. The results were almost all for the pair of rotors. Many didn't provide thickness, so you would have to ask the seller to measure them. Others had the thickness. Depending on miles, the bobbins might be worn and need replacement. There have to be at least a couple of them that are worth trying. You can alsways return them if they aren't flat or don't measure what you were told.  If they come without the ABS ring, you can move it from your old OEM disk to the new one.

 

 

[dirtrider]

Quote

I was just looking for info to see if I could get new bobbins for the EBC rotors/carriers if they are a different size from BMW ones, and ran across several youtube videos about how to check/clean the bobbins to make sure they are free spinning and it can eliminate brake judder is some cases.  I think I am going to give this a try as it is basically free with stuff I already have in my garage.  I know that I have never checked or tried to "service" the bobbins before.

Morning Luky

 

Tight bobbins can effect brake judder under some conditions. 

 

If you have brake judder at first braking with cold rotors then it probably isn't the bobbins. Where tight bobbins can show up is after hard braking that heats the brake rotors.  

 

If you can feel the judder feedback in the hand lever (brake corresponding lever judder) then look for possible tight bobbins or brake rotor thickness variation. 

 

If you just have brake judder or brake pulsation but the hand lever is judder free then most likely you have friction variation in the brake pad to rotor grip. (a friction variation causes brake pad grip differences in different areas of the rotor but no fluid kick back into the master cylinder)

 

If you can also feel a brake lever  judder or pulsation in the hand lever then you are getting fluid kickback from some sort of rotor warpage or thickness variation. 

 

On a motorcycle that that been sitting for a long time, or stored (especially with metallic brake pads) a brake judder problem is almost always due to brake rotor staining where the pads were sitting against the brake rotors. 

[Luky]

On 4/25/2024 at 8:03 PM, Michaelr11 said:

 

Put the BMW part number, without spaces, into the eBay search box. I put the right ABS rotor in, 34 11 2 310 484, and got many results. They went from $200 to under $100. The results were almost all for the pair of rotors. Many didn't provide thickness, so you would have to ask the seller to measure them. Others had the thickness. Depending on miles, the bobbins might be worn and need replacement. There have to be at least a couple of them that are worth trying. You can always return them if they aren't flat or don't measure what you were told.  If they come without the ABS ring, you can move it from your old OEM disk to the new one.

 

 

Thanks Michael, but I refuse to do any business with eBay or paypal after they screwed me on a transaction years ago (buyers remorse on a brand new $1.1k item I had bought from our company store with 50% off employee discount and resold on ebay (still at big discount vs retail, listed as "all sales final/no returns").  Then they made unauthorized charges to my account for a "return shipping label" which I refused to pay so they sent it to collections. I told the collections agency to provide written evidence I approved the charges; they couldn't and dropped the collection effort, but it was a big PITA for months, and I was worried about screwing with my credit rating (which is literally a "perfect score").  So no more eBay/Paypal for me.  And this is not uncommon if you do some searching online about problems with these "businesses".

[Luky]

On 4/26/2024 at 3:33 AM, dirtrider said:

Morning Luky

 

Tight bobbins can effect brake judder under some conditions. 

 

If you have brake judder at first braking with cold rotors then it probably isn't the bobbins. Where tight bobbins can show up is after hard braking that heats the brake rotors.  

 

If you can feel the judder feedback in the hand lever (brake corresponding lever judder) then look for possible tight bobbins or brake rotor thickness variation. 

 

If you just have brake judder or brake pulsation but the hand lever is judder free then most likely you have friction variation in the brake pad to rotor grip. (a friction variation causes brake pad grip differences in different areas of the rotor but no fluid kick back into the master cylinder)

 

If you can also feel a brake lever  judder or pulsation in the hand lever then you are getting fluid kickback from some sort of rotor warpage or thickness variation. 

 

On a motorcycle that that been sitting for a long time, or stored (especially with metallic brake pads) a brake judder problem is almost always due to brake rotor staining where the pads were sitting against the brake rotors. 

Hi DR, I do not feel it at the lever, just sort of in my body when braking at lower speeds (say 25mph to 10mph) I can feel the pulsing, and not as noticeable braking at higher speeds.  I did some light spin cleaning of the rotor buttons with brake cleaner flushing them out as several were really stuck, and it helped, but didn't eliminate the issue. It really sounds like the "staining" you mention, and I bought some of the red scotch bright pads to try and "spin clean" the rotors.