Airhead brakes help

Discussion in 'Airheads' started by italiano, Jan 4, 2012.

  1. italiano

    italiano Been here awhile

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    I have a 78 r 100 with the ATF brakes and the fork that does not support any change on brakes, what is a good brake upgrade that i can do? i really does not want to change fork in order to change calipers, so what other alternatives do i have left? Do you know if i remove the master cylinder under the tank and i install one over the handlebars i will notice any changes?
    #1
  2. Houseoffubar

    Houseoffubar HoFmetalworks.com

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    ATE brakes can be improved quite a bit. They will never be great, but decent brakes can be had. The first, and perhaps best modification would be to go with the handle bar mounted master cylinder. I would do this before anything else. A lot of people here have done this, try the searce feature, and see what you can find. :D
    #2
  3. Wirespokes

    Wirespokes Beemerholics Anonymous

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    The under tank master works just fine - the problem is that the ATE brakes were the first discs BMW installed and didn't get the master size correct. They're too large and pump too much all at once. Because of that the leverage is wrong with the lever barely moving before the pistons lock up. The early bar mounted masters were the same. Dual discs work well with a 13 or 14mm master and the singles with a 12. The under tank master for the single disc is perfect for dual discs.

    Good, non glazed brake pads, fresh fluid, pads correctly adjusted and everything working freely will make a huge difference.
    #3
  4. bay

    bay Adventurer

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    hi i have just done this modification myself. all you need is the handlebar mounted master cylinder stainless hoses and good brake pads.spend a little time to bleed the brakes and set the pads level with the discs and there great
    #4
  5. italiano

    italiano Been here awhile

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    Were did you buy your master cilinder ?
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  6. mykill

    mykill odd

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    Be specific people! Years and models to steal from?
    IIRC Johnnycash (inmate) did a conversion with a Magura radial MC with some mods to his perches.
    #6
  7. Wirespokes

    Wirespokes Beemerholics Anonymous

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    Any of the airheads from 81 till 95 except the G/S and 100R used the same controls, so the switches will mount right on. The early R65 controls and the post 85 airheads had two throttle cables exiting the control where the 81-4 only had one. The single disc system worked best with a 12mm master (the smallest size, I believe) and the dual with a 13 or 14.
    #7
  8. Reynard38

    Reynard38 Adventurer

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    I went with Spiegler semi floating rotors on my '88 R100RS. That with some good pads and stainless lines and it really does stop well. Also the lever is very hard. Its very easy to modulate the brakes now.
    You send your existing rotors and carriers to Spiegler. They cut the old rotors off and install the new ones on your carriers.
    #8
  9. trophymoto

    trophymoto MACDADDY!

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  10. boxerboy81

    boxerboy81 Stay Horizontal

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    The 81-84 R100's had the 15mm mc. I replaced mine with a 13mm from the later R80 mono. Much better feel, and slightly longer lever travel allows a more progressive feedback to the brake.

    The ATE's benefit from the mc being loosened from the frame and tilted a little to allow for easier and better bleeding of the air from the system.
    #10
  11. italiano

    italiano Been here awhile

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    were can i buy a hb master cylinder in order to replace the under tank mc?

    after reading a lot on this topics it seem that it can be ether 13 or 14 mm.

    can i go with a used ones? were to buy it?
    #11
  12. boxerboy81

    boxerboy81 Stay Horizontal

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    http://www.motobins.co.uk/

    A used one could work, but you'd want to dismantle and check the bore for corrosion first...or risk it.
    #12
  13. Rob Farmer

    Rob Farmer Long timer

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    The disks have to be really good and flat, particularly the rear of the disk, for the ATE calipers to be setup properly.

    I have a 78 R100/7 thats been converted to a Brembo braked front end. The Brembos always feel wooden and lack feel but they are consistent and easy to work on. To be honest I prefered the ATE setup with a handlebar master cylinder that I had on my RS for feel and didn't feel the brakes performed and worse than the Brembos. They did need the cash throwing at them though to convert to the handelbar kit and buy decent disks.
    #13
  14. Big John Sny

    Big John Sny Long timer

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    I converted to brembos. It transformed the bike. I ran the single brembo in it till I got a second disc and it was better with the under tank master than my single ATE was. Now with the entire set up from the 82 RT (including handlebar master) it stops well. Not modern sportbike well, but much better than it did and as good or better than many bikes I have ridden. I commute in heavy traffic so I do not think I could have justified continuing to commute on this bike if it had not made such an improvement. I had gotten to feel the complete capability (or lack thereof) to many times. The real difference is pulling it down quickly from freeway speed. The old brakes felt ok at lower speeds, but the first time I had someone yank out in front of me on the freeway, I got to feel how wooden they get at that speed. It was progressive to a point but then will not brake any faster no matter how hard you pull on the lever. I have not experienced that in 10,000 since I changed to brembos. Best money I have spent on the bike.
    #14
  15. Hawk Medicine

    Hawk Medicine Coyote's Brother

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    You're going to have to use some brainpower on this one! Try your local BMW wrench, here in the flea market, The IBMR board, The MOA Flea Market, there are parts people listed in the "Airmail"....

    If you want the parts, you're going to have to expend some time, energy and cash. It's either that or shell out for a new part. Hell, I bought three or four complete Airheads to get the parts I needed to build mine!

    PS: A well set-up ATE system is just as good as 80s era Brembos and IMO have better feel. a 14mm HB Master, rebuilt calipers, rebuilt forks SS lines and cleaned up disks will work wonders. When I had both systems in my garage, the ATEs on my /6 were as good as or better than the Brembo's on my RS. I think they're better.
    #15
  16. Wirespokes

    Wirespokes Beemerholics Anonymous

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    Once the two systems - ATE and BREMBO - are set up properly, I think they're both comparable, and the differences we've been seeing - some say ATEs are better, others Brembo - is due to differences in brake pads. If say, the 'new' brembos you just installed have new proper pads and the 'old' ATEs have old glazed pads, then you'll think it was an excellent upgrade.
    #16
  17. supershaft

    supershaft because I can

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    I wanted to +1 BJS in this ongoing debate. Both ATE's and Brembos setup to perform their best? The Brembos are on a different planet better. In theory and practice. If you think ATE's are on the same playing field as Brembo's, you need to get into the Brembo's a lot more. There is a lot more there! Way easier said than done I know but . . . .
    #17
  18. puncar thogoole

    puncar thogoole Been here awhile

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    My R80/7 under tank twin disc ATE setup is finally at a point where I'm happy with it, by that I mean I can go back and forth from my R1150 & not be frightened when I jump on the airhead.
    Over time it has taken a pair of cast discs, braided steel hoses, re-built calipers & a single disc 14mm under tank master rather than the old 17mm twin disc one, I know it doesn't sound like much difference but it's more or less a 50% decrease in cylinder bore.
    I'm not going to pretend they are on a par with the 1150, but I can stop pretty much as quickly as the front tire will allow with an adequate amount of "feel" at the lever.
    The ATE under tank master cylinder comes in for a lot of flack but I don't have a problem with it if it's in good condition, well adjusted & maintained along with the cable, I prefer not to have a fluid reservoir on the handlebars but that's just personal preference.
    The single disc master (14mm) can be drilled & tapped for duel lines or if you're replacing the hoses you can utilize a single hose with a splitter nearer the calipers.
    The calipers need to be aligned correctly or it's all a waste of time.

    Edit- I have no experience of a Brembo braked airhead, but I can relate to the fear/hate of ATE's, having ridden a single SS disc ATE setup I can confirm it was appalling (same maybe as BJS?), truly frightening, anybody using something like that as a measure of ATE brakes are justified in slagging them off, in that particular case had the nasty single ATE been replaced with Brembos I'd sure I'd be singing Brembos praises as well.
    #18
  19. italiano

    italiano Been here awhile

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    Yesterday i make the swap without connecting the brake hoses between a rs 81 handlebar mc and my 78, it will phisically fit, but the mc is 15mm. Will i have any trouble with that?. Also i am using bmw pads, wich pads do you recomend best? I think i will try to do this swap before changing the front fork.
    #19
  20. puncar thogoole

    puncar thogoole Been here awhile

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    If you have a twin disc setup your under tank master cylinder will have been 17mm bore, so 15mm will be an improvement, it'll be roughly a third more leverage, though it won't necessarily feel like that.
    BMW pads are fine if they are not old or "glazed"(have a shiny surface).
    #20