MOTOBRICK.COM
TECHNICAL MOTOBRICK WRENCHING In Remembrance of Inge K. => The Motobrick Workshop => Topic started by: 1991K100RS on July 12, 2014, 08:28:57 PM
-
Hey all,
The front rotors on my 1991 K100RS are wearing thin and need to be replaced. I pulled up the BMW microfiche for 1991 K100RS and I find that there are part numbers for ABS rotor and one that doesn't show ABS.
My bike is ABS. I am interested in buying aftermarket - EBC Brake Rotors - because they are significantly cheaper. I'm looking at these;
MD607RS Rotor
http://www.amazon.com/EBC-Brakes-MD607RS-Brake-Rotor/dp/B006B29IRM/ref=sr_1_2?ie=UTF8&qid=1405211191&sr=8-2&keywords=MD607RS (http://www.amazon.com/EBC-Brakes-MD607RS-Brake-Rotor/dp/B006B29IRM/ref=sr_1_2?ie=UTF8&qid=1405211191&sr=8-2&keywords=MD607RS)
MD611 Rotor
http://www.amazon.com/EBC-Brakes-MD611-Brake-Rotor/dp/B006B25Q1O/ref=sr_1_2?ie=UTF8&qid=1405211245&sr=8-2&keywords=1991+k100+rs+brakes (http://www.amazon.com/EBC-Brakes-MD611-Brake-Rotor/dp/B006B25Q1O/ref=sr_1_2?ie=UTF8&qid=1405211245&sr=8-2&keywords=1991+k100+rs+brakes)
Are the right and left rotors different? I see these 2 listed as fitting my bike... but not sure if I need 1 of each, or 2 of the ABS type rotor. Any insight on these is appreciated :)
-
By looking up the oem brake disc numbers for a 90-92 K100RS with and without ABS at Max BMW, I see that the right hand disc has the same part number for non-ABS and ABS. I would get from this that you should order one of each. Take a look here to decide for yourself. The left hand side where the ABS ring is are different.
-
rs = right side
ls = left side
md611 = back side
j o
-
I took a look at the EBC catalog online. http://www.ebcbrakes.com/Assets/ecatalogues/2014-US-MC-Catalog/2014-us-mc-catalog.html#p=78 (http://www.ebcbrakes.com/Assets/ecatalogues/2014-US-MC-Catalog/2014-us-mc-catalog.html#p=78)
It confirms the above post about RS = right side and LS = left side.
-
Adding to the notes in the catalog page, you will have to re-fit your ABS rings to the new rotor carriers.
-
Makes sense - RS and LS for right side and left side
MD607RS / MD607LS to change front rotors. I'm going to buy a set on amazon for $400. Significantly cheaper than OEM (but still not cheap....)
Thanks guys! Cheers
-
I've got a set of used rotors that still have some meat on them, if you're interested. If you use organic pads, they should be good for a long time.
-
Im using OEM BMW brake pads for the front, just bought a new set. I'll message you about the rotors
-
If the brake discs Vmax have is from a K75, they won't fit a -91 K100RS.
-
If the brake discs Vmax have is from a K75, they won't fit a -91 K100RS.
I just realized that too. The 91 k100 is a 4v
-
From what I can see, both front brake discs/rotors are basically the same: the LH one has predrilled holes for the ABS ring, but would work as a RH disc...are the non ABS discs the same size as ABS? if they are you could swap them about a bit, depending on your bike spec, and what parts are on reduced price offers!
Can you get just the brake disc part that the pads bite on? no need to replace the carrier parts on floating brakes, or all the fixing bobbins, washers and circlips!
-
What's different is the drill pattern.
Other than that, you could actually use two lefts or rights and it'd not be a big deal........ except.......
I found (before I GS'ed my bike) that the brakes pulsed slightly while coming to almost a complete stop. The lever didn't pulse but the apparent friction did.
I thought about it after reinstalling the rotors on my new spoked rim (Lucky me I could re-use them) and when looking at it, you can index the drill pattern so that they are "in phase" or "out of phase" it seems. In other words, looking ACROSS the disks at each other, the holes are either lined up or not.
I think that they were in phase so the friction changes between drilled and undrilled were passing both pads at the same time. Now they are out of phase and it doesn't "pulse".
Bottom line, if you got a really good deal on two lefts or rights, I wouldn't turn it down.
TV
-
Interesting theory....
My K1100 had a bad judder when coming to a stop: nothing wrong with the brakes tho...apart from the RH pads being full of fork oil!
I replaced the fork seals when I bought the bike, didn't realise the leaking oil had got down to the the pads on the RHside :2thumbup:
New EBC HH pads have cured the problem, along with de-greasing the rotor: this took longer than expected as every hole was full of grease-like crap! In the end I stripped the wheel, removed the disc from the mount and washed out in boiling water...didn't want to ruin expensive new pads, but now its stunning! New HH pads on grease free discs are amazing....
-
....... New HH pads on grease free discs are amazing....
Just some food for thought for you, using the HH sintered pads will wear the disk's faster than the original organics. Yes you will have much better stopping power, but shorter disk life.....YMMV
-
im getting 40 thou mileage outta ebc organic brakes pads... aints never changed a disk cause it was thinn...
fa18 rears... (http://www.amazon.com/EBC-Brakes-FA18-Non-Asbestos-Organic/dp/B006B27PRC/ref=sr_1_1?s=automotive&ie=UTF8&qid=1405895947&sr=1-1&keywords=EBC+Brakes+FA18+Non-Asbestos+Organic+Disc+Brake+Pad)
fa407 fronts... (http://www.amazon.com/gp/product/B006B28PVC/ref=oh_details_o01_s01_i00?ie=UTF8&psc=1)
j o
-
I ended up buying the EBC right and leftfront rotors from amazon for $200 a piece and OEM front brake pads for both front calipers.
Had to use a torch on the bolts to remove rotors from wheel, and ABS disc from left rotor... but otherwise, didn't take too much persuasion. Worked well. Thanks for sharing your thoughts guys!