Linked brake nerd question - 2012 GS

Discussion in 'GS Boxers' started by hillbillypolack, May 17, 2013.

  1. hillbillypolack

    hillbillypolack Grumpy Old Goat

    Joined:
    Jul 29, 2005
    Oddometer:
    7,878
    Location:
    Lidsville
    This afternoon I swapped the rear brake lever to the GSA design with the flip down beartrap. I did this since the standard GS lever felt it was engaging too low despite my adjusting it.

    The swap was easy, straightforward. I checked the brake was operating normally and the calipers weren't dragging. On a ride this afternoon I noticed two things : one was that the rear brake felt warmer then the fronts when I stopped for gas. I often use both F & R brakes mostly out of habit. Since the GS has linked brakes, when I use the rears am I using too much rear (thus heating the rotor too much)? Or is it possibly a by product of the smaller rotor taking more heat due to smaller surface area?

    The second thing I noticed was the banjo fittings were / are a light blue tint. At first I cringed, thinking I was cooking the fluid and discoloring the fittings. The rotor isnt the rainbow dark blue of a dragging brake pad, so I looked at the front fittings which are also light blue. I didn't notice this before, but the systems feel like they are operating as they should.

    So I guess my question is if I am using the rear brake on a GS (with linked brakes) am I using too much rear? Or is a little more heat for the rear rotor considered normal?
    #1
  2. 200GRLSWC

    200GRLSWC Been here awhile

    Joined:
    Apr 22, 2013
    Oddometer:
    108
    Don't know if this is useful or not, but my experience with rear brakes on the GS.

    First, I almost never touch the rear brake lever, unless I'm on dirt. Since I ride 98%+ on street, that means I effectively never touch my rear brake lever.

    When I had my '06 GS, my rear brake pads were down to metal at the first 6,000 service. I was astonished. The dealer suggested I might be resting my foot on the rear brake lever, but I knew that was nonsense. Back in those days I had the dealer do the work (that very bill was the driver that broke me of THAT habit), and they replaced the rear pads. I sold that bike with about 20,000 miles on it, and never needed to replace the rear pads in those additional 14,000 miles. Clearly, something had changed.

    On my '08 GSA I just finished the 24,000 mile service (I do my own service now), and the brake pads have plenty of life left in them, both front and rear. (Yes, I ride like an old man, get over it. :rofl) Again, clearly something was different than my experience on the first 6,000 miles of my previous GS.

    I suspect that on some GS bikes the "linked brakes" mechanism that apportions some pressure to the rear caliper even when you use only the front brake lever only may in fact provide too much pressure to the rear, causing excessive wear on the rear pads. I think that's what happened on my '06 GS, and that then the dealer either adjusted or replaced something in the linked brakes mechanism and the distribution of braking force was changed to prevent excessive rear pad wear.

    Just one rider's experience.
    #2
  3. hillbillypolack

    hillbillypolack Grumpy Old Goat

    Joined:
    Jul 29, 2005
    Oddometer:
    7,878
    Location:
    Lidsville
    ^
    Thanks. Kinda my thoughts as well. I'm used to settling the rear with a bit of rear brake on other bikes. That 'habit' followed me on the GS. I likely would not have noticed the rears being warmer than the fronts if I hadn't changed out the brake pedal. The bike brakes well enough by using the front brake lever but really stops when both ends are clamped down tight in an emergency.

    I did a coast-down check to ensure neither end was dragging (up to 40 mph then coasting to a stop. then feel the rotors for any heat). Neither was. I also took a closer look at the brake line fittings. All are a light blue color which again I didn't notice before. Not a biggie, but seeing the coloration on the caliper fitting had me thinking I was cooking brake fluid!
    #3
  4. Mudcat

    Mudcat Unregistered

    Joined:
    Jul 22, 2004
    Oddometer:
    4,472
    Location:
    Bay Area
    I completely ignore the linkage system on my 05. I use the brakes as if they are conventional hydraulic disc brakes and I believe the brakes perform better doing this.
    However, I have been led to believe that on later model GS’s, 2008+, one can not ignore the linkage system as I do. This has completely ruled out a new BMW for me. :cry
    #4
  5. Snarky

    Snarky Vodka Infused.

    Joined:
    Feb 24, 2011
    Oddometer:
    1,343
    Location:
    Old El Paso and Swamp Houston
    Cry no more, they act just like any other bike when you touch the rear brake.
    #5
  6. Mudcat

    Mudcat Unregistered

    Joined:
    Jul 22, 2004
    Oddometer:
    4,472
    Location:
    Bay Area
    Yeah, I use both brakes almost all the time.
    Are you saying I can ignore the linkage on the newer models without the front brake interfering with rear brake usage? Because if you are. I have heard from others on this forum that I can’t.
    <?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:eek:ffice:eek:ffice" /><o:p> </o:p>
    I don’t want linked brakes:deal
    #6
  7. Hambonee

    Hambonee Been here awhile

    Joined:
    Jul 20, 2011
    Oddometer:
    176
    Location:
    Western Washington
    I was told that(on my 2013) if you hit the rear brake first it disables the linking. Since I always do other than possible panic stops linked brakes not an issue:clap

    That being said now gonna go play with it to check stopping with just front then rear and front...got me curious...lol:rofl
    #7
  8. /dev/null

    /dev/null Been here awhile

    Joined:
    May 24, 2011
    Oddometer:
    177
    Location:
    Southern California, USA
    How do you adjust the front/rear bias/gain on the linked braking system (08+)?

    I too have been told by my dealer (who historically has offered sage advice) to avoid the rear brake almost entirely. Adding rear brake will simply overuse the rear. Use only the front in spirited riding or even a panic stop. Use the rear off-road only.

    My introduction to this issue was a warped rear rotor. Pads were fine in my case, and the issue did not appear to be wheel/wheel flange related. When I swapped to my '11, 10k later, I did notice the replaced rear rotor felt as though it was beginning to warp again (in the lever, or with the rear pedal). I never did a heat check or coast-down check. My best guess is that the brakes were biased incorrectly (if this is possible)?
    #8
  9. hillbillypolack

    hillbillypolack Grumpy Old Goat

    Joined:
    Jul 29, 2005
    Oddometer:
    7,878
    Location:
    Lidsville
    In a nutshell, that was my hunch.
    #9
  10. TUCKERS

    TUCKERS the famous james

    Joined:
    Dec 23, 2005
    Oddometer:
    13,931
    Location:
    Villa Maria Sanitarium, Claremont, CA. USA
    No you are not using too much rear when you use your rear brake. Brake just like you would on any motorcycle.

    The habit of JUST using the front ALL the time ONLY is a bad habit.

    One of the worse things you can do is use your front brake to come to a stop from a slow speed.

    It's okay to 'scrub' some speed from your bike with front brake only, but using it for stopping is not correct, safe or judicious procedure.
    #10
  11. Mudcat

    Mudcat Unregistered

    Joined:
    Jul 22, 2004
    Oddometer:
    4,472
    Location:
    Bay Area
    Its bad technique but safer for many people. :evil
    I must say, I think the linage is crap. :deal
    I am confused as to what year the linkage can no longer be ignored. I know a couple of years ago BMWAtlanta, who is a BMW dealer, was advocating using both brake levers, ignore the linkage. Not that I find BMW Dealers completely creditable but he seemed like a real knowledgeable rider to me.
    Anyway, on my 05 I can and do ignore the linkage system. And I’m a happy camper. :D
    #11
  12. /dev/null

    /dev/null Been here awhile

    Joined:
    May 24, 2011
    Oddometer:
    177
    Location:
    Southern California, USA
    The problem is that they're set up so using the front only gives you the correct bias. Adding rear gives you more rear bias. Brakes are only linked front to rear on these (at least 08-13 oilheads).

    The bad habit aspect is very annoying to me, especially when I get on my FZ1 without linked brakes where I need to do things the "right" way.
    #12
  13. scooteraug02

    scooteraug02 Dog Rancher

    Joined:
    Feb 18, 2003
    Oddometer:
    4,555
    Location:
    Atlanta, GA
    Could you have installed the lever to high so that your foot is resting on the pedal, applying rear brake all the time?

    On my 08 if I add too much rear brake the ABS kicks in on the rear tire.
    #13
  14. marchyman

    marchyman DR and GS

    Joined:
    Jun 30, 2005
    Oddometer:
    8,691
    Location:
    SF Bay Area
    I ignored it on my '05. I also ignored it on my wethead test ride. I plan on ignoring linkage when my wethead is eventually delivered. I always use the rear brake at low speeds; both brakes for quick stopping.

    The "over braking" worry is, IMHO :topes You can feel the braking power and adjust the pedal appropriately. If you really go overboard on the rear the ABS will kick in to let you know.
    #14
  15. justinallen03

    justinallen03 Been here awhile

    Joined:
    Dec 9, 2010
    Oddometer:
    213
    Location:
    greenville, sc
    I don't think the link is heating up your rear brake any more. The linking applies pressure somehow (I think its a servo motor/pump) based on the front brake input. Your input to the rear brake pedal would have to overcome this pressure applied by the pump before you would generate any more braking force. I don't think it takes much more than what the linking system provides to lock up the rear, or at least what ive thought after burying the rear pedal on a stop. I think you would notice excessive rear pad wear too.

    I think the rear stays hotter mainly because airflow is greatly blocked by the wheel and swingarm, and what air it does get is heated up from crossing the engine and cat.

    I personally like the linking...one less thing to worry about during the oh shit moments. The times I don't want it I just flip off the ABS.
    #15
  16. Mudcat

    Mudcat Unregistered

    Joined:
    Jul 22, 2004
    Oddometer:
    4,472
    Location:
    Bay Area
    Yep, but these guys believe BMW’s marketing department. 30% :evil
    <?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:eek:ffice:eek:ffice" /><o:p> </o:p>
    Here is what bemiiten had to say about the linked brakes on his 2011 GSA:
    Manual for my 2011 says the same. Sort of makes sense being it's impossible to modulate the rear through the lever without affecting the front. And modulating the front screws up the rear when your using the foot brake. <?xml:namespace prefix = v ns = "urn:schemas-microsoft-com:vml" /><v:shapetype id=_x0000_t75 stroked="f" filled="f" path="m@4@5l@4@11@9@11@9@5xe" o:preferrelative="t" o:spt="75" coordsize="21600,21600"><v:stroke joinstyle="miter"></v:stroke><v:formulas><v:f eqn="if lineDrawn pixelLineWidth 0"></v:f><v:f eqn="sum @0 1 0"></v:f><v:f eqn="sum 0 0 @1"></v:f><v:f eqn="prod @2 1 2"></v:f><v:f eqn="prod @3 21600 pixelWidth"></v:f><v:f eqn="prod @3 21600 pixelHeight"></v:f><v:f eqn="sum @0 0 1"></v:f><v:f eqn="prod @6 1 2"></v:f><v:f eqn="prod @7 21600 pixelWidth"></v:f><v:f eqn="sum @8 21600 0"></v:f><v:f eqn="prod @7 21600 pixelHeight"></v:f><v:f eqn="sum @10 21600 0"></v:f></v:formulas><v:path o:connecttype="rect" gradientshapeok="t" o:extrusionok="f"></v:path><o:lock aspectratio="t" v:ext="edit"></o:lock></v:shapetype><v:shape id=_x0000_i1025 style="WIDTH: 11.25pt; HEIGHT: 11.25pt" alt="" type="#_x0000_t75"><v:imagedata o:href="http://d26ya5yqg8yyvs.cloudfront.net/puke2.gif" src="file:///C:\DOCUME~1\BIGORA~1\LOCALS~1\Temp\msohtml1\01\clip_image001.gif"></v:imagedata></v:shape>I'm assuming even if you 'deactivate' by using the foot brake, The ABS function remains through the lever. I'd love to just shit can the whole system and decide for myself how much braking I want on each wheel, just like I've been doing for 30 years. When it comes to ABS/ linked brakes, I feel like part of the riding experience has been taken from me.
    <o:p> </o:p>
    My experience has been, ignoring the linage just improves brake feel and performance. The caveat is, on downhill’s ABS is activated by the rear of the bike becoming a little light. I hate it; I ride with ABS off 99% of the time.
    <o:p> </o:p>
    How long did they let you test ride the 2013 for?
    #16
  17. bobbybob

    bobbybob Long timer

    Joined:
    Sep 5, 2008
    Oddometer:
    1,573
    Location:
    Charlotte, NC
    Oh really?? Why??
    #17
  18. marchyman

    marchyman DR and GS

    Joined:
    Jun 30, 2005
    Oddometer:
    8,691
    Location:
    SF Bay Area
    Long enough to decide I wanted one :deal

    I had it out for about an hour, maybe a little more. Mountain View to Page Mill to Skyline to 84 to Sand Hill to I280 and back to Mountain View. Might have taken longer to place the order with the options I wanted. I didn't want one of the "standard" packages that bike that BMW is pushing. That means a long wait (ordered end of March, build in May, delivery in ?).
    #18
  19. Mudcat

    Mudcat Unregistered

    Joined:
    Jul 22, 2004
    Oddometer:
    4,472
    Location:
    Bay Area
    #19
  20. Botch

    Botch Been here awhile

    Joined:
    Mar 17, 2013
    Oddometer:
    568
    Location:
    Ogden, Utard
    Glad i did a search on "linked brakes"; I was wondering too what percentage brake force was applied to each end (I have an '09) and if any footbrake should be applied in a panic stop (from experience, it probably always will be for me).

    I got into the bad habit of using only front brake on my first MC, and the MSF folks tried very hard to break (har!) me of the habit in one weekend. I'm finally learning to use only the rear brake when at parking-lot speeds with Pig; using the hand brake only (even if its linked) unsettles this bike and I'm probably gonna drop Pig soon if I'm not careful. :cry
    #20