320mm Brake upgrade for G/S

Discussion in 'Old's Cool' started by One Less Harley, Feb 9, 2009.

  1. One Less Harley

    One Less Harley OH.THAT'S GONNA HURT

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    OK after hashing out whether to ad another disc, or some other method of upgrading brake I decided to go w/ a 320mm brake upgrade. I think stock is 260mm. As Of now I cannot comment on the improvements as you can see I have no front tire.

    This uses the stock caliper and just relocates the calipers outbound a bit, comes with a spacer for the rotor and needed bolt to mount the caliper and disc. I got this from Seinbenrock. It is suggested to get another brake line but the old one will work.

    One thing I don't like and has nothing to do w/ function is that the bracket which mounts to the fork needs to have the mounting bolts recessed into the bracket. I may have this done later.


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    #1
  2. johno

    johno Long timer

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    Thats a strange looking disc:huh
    Looks like a floater, but its not.

    Should definately work better though.
    #2
  3. One Less Harley

    One Less Harley OH.THAT'S GONNA HURT

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    It's a solid disc which have been laser cut at a few locations to take care of heat expansion and probably help keep it from warping.

    I had the aluminum countersunk for the mounting bolts. A much neater look.

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    #3
  4. woodgrain

    woodgrain In-Dented Savant

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    How much for the Siebenrock kit?

    Woodgrain
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  5. One Less Harley

    One Less Harley OH.THAT'S GONNA HURT

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    USD Cost- $311.98 plus $41.40 shipping from Germany.



    Probably cheaper to get someone to make another bracket for a four pot caliper, but might have to change brake lines and possibly the MC. The stock brakes aren't that bad w/ standard tank and unloaded...not great but adequate.
    #5
  6. StephenB

    StephenB G(/)S ... what else!

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    Or, for a lot less, you can use a 2000 or so K1200R (re-badged Brembo) 4-pot caliper (34/32mm) on a stock disc with great stopping power:

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    Use a left caliper with bracket for the G/S location behind the fork leg.
    #6
  7. England-Kev

    England-Kev Long timer

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    Are there any options for four potting an ST front end?
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  8. Caddy82rats

    Caddy82rats Long timer

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    The ST use the same calipier so the 4 pots conversion would work
    #8
  9. Gimmeslack

    Gimmeslack furthur

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    Anybody have a link to more info on this mod? e.g. does stock bracket work? Shims...? Does master cyl need to be re-thought? etc...

    #9
  10. StephenB

    StephenB G(/)S ... what else!

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    On a stock GS you only have to shave a bit (4mm) off the mounting brackets of the caliper, otherwise it is plug 'n play. I made no changes to the m/c. I think mine is stock GS 12mm.

    Dunno about doing the mod on a G/S but I assume you need a custom bracket.
    #10
  11. One Less Harley

    One Less Harley OH.THAT'S GONNA HURT

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    Took the bike out for a test ride w/ the 320mm rotor, don't know what pads are on the stock caliper, but getting the front wheel to chatter and lock up is not a problem now. First ride and I like it so far. Nice upgrade w/ no fuss on installation.
    #11
  12. One Less Harley

    One Less Harley OH.THAT'S GONNA HURT

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    For stephnb's conversion notice it's for a GS no a G/S, but the principles of the conversion are the same.
    #12
  13. jellycow

    jellycow Back on track.. Oh, wait, new track found!

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    I've had the same HE disk on my former r100gs. Combined it with a 4 pot calliper. The shear stoppingpower (well, for 2v-alikes :lol3) Used the left side calliper from a r100r and just had to take about 5,5mm off the spacer. Easy fix, good result.
    Now, by the time the disk on my G/S is worn and the 2 reserves after that I'll have saved enough money to buy the HE for G/S and so it'll be done.

    BTW: it is just about floating, the lasercuts are in such locations that there is some room for the disk to move, just as on a really floating disk.
    #13
  14. Solo Lobo

    Solo Lobo airhead or nothing

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    Nope, the BMW 4-piston caliper does not work on a G/S nor ST.... I can tell you that for sure.

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    Boxerworks sells a machined adapter to do this mod, but the caliper ends up almost below the wheel and looks to be in a bad place for off-road riding.

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    #14
  15. One Less Harley

    One Less Harley OH.THAT'S GONNA HURT

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    Solo, that conversion looks hoaky as hell....hope it's not your bike. Yeah I knew the four pot wasn't plug and play even with shaving the caliper as the spacing for the mounts are different.

    I really am enjoying the 320 disc, it's been fun today hearing the front tire squeal and locking it up. Never could do on the R1150RS. If I could only get the wobble taken care of, still fighting with that, along with a wheel hop, dyan beads didn't fix that. I'll try and get the wheel spin ballanced tomorrow. Gotta fix the wheel hop and wobble. But Not ready for buying a rear shock, cann't affoard it right now.

    I've got some calipers coming from an early RT (117mm spacing for the mounting bolts, like the G/S) and will still look closer at the spacing, but I'm thinking even w/ the shallow rotors some spacers will need to be made, then have to make sure the calipers don't hit the spokes. Carrier spacers wouldn't be any big deal to make.
    #15
  16. Solo Lobo

    Solo Lobo airhead or nothing

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    That's Nathan from boxerworks bike...(I think)

    Here is the conversion I am chasing (also not my bike) It's a 4-piston from an early FZR 1000 that a guy in England has done.. I have the caliper and have cut down the caliper ear but haven't done much else yet...

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    #16
  17. Caddy82rats

    Caddy82rats Long timer

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    OK ! Pics speak more than thousan words ! Maybe it's possible tu fit a larger disc on the BMW carrier ? like a 300mm iron ?
    #17
  18. Solo Lobo

    Solo Lobo airhead or nothing

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    Finding a vendor to do that is the hard part!

    The G/S carrier is a five bolt one that is kinda unique.... I would like to find a US shop that can place a larger rotor on the stock carrier. There is someone in the BMWMOA magazine who does do BMW re-rotoring, but they one put the stock size onto the G/S rotors, and don't/can't do bigger ones...
    #18
  19. Caddy82rats

    Caddy82rats Long timer

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    #19
  20. JA Adv

    JA Adv Adventurer

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    #20