Improving ATE brake feel on '74 bikes

Discussion in 'Airheads' started by inigoj, Oct 21, 2017.

  1. black knight

    black knight Long timer Supporter

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    DOES ANYBODY KNOW MORE ABOUT THIS GUY IN WASHINGTON ??
    OR
    HIS WORK.

    HAS ANYBODY HAD THIS DONE ON THEIR AIRHEAD ????


    Modification of fork legs for the r90x big brake adapters

    $30
    Bellingham, WA (98225)

    Machining of your fork leg to match my adapters. $30 plus shipping for machine work. For a total of $64 plus shipping I'll install a new seal, bottoming bumper, large cap washer, and include the small damper rod washer.

    https://www.facebook.com/groups/111...43668615748668/?sale_post_id=1143668615748668

    OPEN LINK TO SEE BRAKE WORK ...

    Modification of fork legs for the r90x big brake adapters
    Bellingham, WA (98225)
    $30

    Machining of your fork leg to match my adapters. $30 plus shipping for machine work. For a total of $64 plus shipping I'll install a new seal, bottoming bumper, large cap washer, and include the small damper rod washer.

    this guy converts type I fork BRAKES to what you see ....

    https://www.facebook.com/mattcfish?...xIMLtiujJ2MlzmoGzx7WVPEqyPlhIh4bA&pnref=story

    DOES ANYBODY KNOW MORE?
    Bellingham, Wa.

    [​IMG]

    this guy converts type I fork BRAKES to what you see ....

    https://www.facebook.com/mattcfish?...xIMLtiujJ2MlzmoGzx7WVPEqyPlhIh4bA&pnref=story
    #21
  2. Wirespokes

    Wirespokes Beemerholics Anonymous

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    I assume "master-cylinder pin" = piston?

    Mastercylinders use cup seals - is that what you mean by using the same o-rings?

    A little known fact is that the brake parts aren't metric - actually imperial - and given a close metric designation. I don't recall exactly, but think the 14mm master is actually a bit less than 14mm. So you're probably not talking about much of a difference (stock 14 which is probably more like 13.5, down to an actual 13mm). The 14mm under-tank master is easier and cheaper to convert since it only requires adding the second port - or a splitter. The reason it feels different than your bar mounted master is the lever which adds added leverage, of course.
    #22
  3. black knight

    black knight Long timer Supporter

    Joined:
    Dec 2, 2009
    Oddometer:
    1,028
    DOES ANYBODY KNOW MORE ABOUT THIS GUY IN WASHINGTON ??
    OR
    HIS WORK.

    HAS ANYBODY HAD THIS DONE ON THEIR AIRHEAD ????


    OPEN LINK TO SEE BRAKE WORK ...

    Modification of fork legs for the r90x big brake adapters
    Bellingham, WA (98225)
    $30

    Machining of your fork leg to match my adapters. $30 plus shipping for machine work. For a total of $64 plus shipping I'll install a new seal, bottoming bumper, large cap washer, and include the small damper rod washer.


    this guy converts type I fork BRAKES to what you see ....


    https://www.facebook.com/mattcfish?...xIMLtiujJ2MlzmoGzx7WVPEqyPlhIh4bA&pnref=story


    DOES ANYBODY KNOW MORE?

    Bellingham, Wa.



    this guy converts type I fork BRAKES to what you see ....

    https://www.facebook.com/mattcfish?...xIMLtiujJ2MlzmoGzx7WVPEqyPlhIh4bA&pnref=story

    this guy converts type I fork BRAKES to what you see ....
    [​IMG]

    https://www.facebook.com/mattcfish?...xIMLtiujJ2MlzmoGzx7WVPEqyPlhIh4bA&pnref=story


    DOES ANYBODY KNOW MORE?

    Bellingham, Wa.



    this guy converts type I fork BRAKES to what you see ....

    https://www.facebook.com/mattcfish?...xIMLtiujJ2MlzmoGzx7WVPEqyPlhIh4bA&pnref=story
    #23
  4. black knight

    black knight Long timer Supporter

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    #24
  5. mattcfish

    mattcfish R90X Supporter

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    I'm the guy in Washington.
    The pics above are of an earlier version of my mod. What I do now is sell adapters that allow you to fit Ducati 999 320mm rotors or 1098 330mm rotors and a modern 4 pot radial caliper to modified ATE forks.
    For a small fee I can even modify a left fork to fit on the right side with my set up. For wire wheels you need to use a 330mm disc and some additional 5mm spacers to get extra clearance. I also recommend using GSXR600,750 Brembo calipers for wire wheels because they are narrower.
    If you are thrifty like me, you can buy my adapters, find used rotors, fab up hoses, and even add a modern MC for under $600 to $800. A stock MC can be used with a single or even a dual set up, and will substantially improve braking. A modern MC makes your old airhead stop with 2 fingers like a modern sport bike. You will be amazed at how much more you will enjoy riding these bikes. Everything improves when you know you can stop.
    The adapters are selling at a reduced price right now. $179 for single, $350 dual, shipping free in the US.
    I don't have many left, once sold out, it will be at least a month before I have more and production costs will be higher.
    Check out the FB link, PM me, or email me at [email protected].

    https://www.facebook.com/groups/1114082135373983/
    #25
  6. mattcfish

    mattcfish R90X Supporter

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  7. bentombed

    bentombed Been here awhile

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    yep mastercyliner pin = piston. English is not my first language. With this conversion apparently you no longer need the cup seals for it all to work, you can get the required pressure with orings. I will find out more for you.
    #27
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  8. Wirespokes

    Wirespokes Beemerholics Anonymous

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    I've never heard of a master cylinder using o-rings. Every one I've ever worked on had cup seals. What I'd meant to say before was that even if the piston is turned down slightly to 13mm, it's such a small amount, the standard cup seals will probably still work.

    mattcfish - nice looking setup! However, I must say that going to a smaller master (the stock 14mm) with dual discs has worked well enough for me. I never had any attention on being able to stop. Then again, I rarely push the bike close to the ton, or if I do go fast, I don't anticipate stopping. I'm not in a place where I'll need to stop. Maybe if I was racing they'd come in handy, but the stock brakes have served me just fine, and I usually don't use more than two fingers. After a certain point, the tire will lose traction, so the solution is to run stickier tires. And then the limit is the rear wheel lifting off the ground. Control will most likely suffer due to the forks flexing. I just don't see riding an airhead in that fashion. They weren't ever designed for that. For racing, yeah, good idea - along with all the other mods necessary. Reminds me of my brother using his Dodge Dart - rear seat removed - like a pickup collecting rocks from the river. A few times of that and the axle broke, driveline broke, a spring broke, etc. It dawned on him he should really get a pickup instead. Use the right tool for the job. My point is that your brakes are cool, for sure, but most likely overkill. Much stronger than needed for an airhead.
    #28
  9. mattcfish

    mattcfish R90X Supporter

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    Good brakes aren't for performance, they will save your life. Your rear wheel, will not lift, control will not suffer, the rider has total control over how much braking is applied. But braking is now taken to the level where it reduces the importance of how strong the riders grip is and how quickly the rider can react. Brakes are now a better tool for the job.
    #29
  10. airheadPete

    airheadPete Wherever they send me. Supporter

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    Well, it’s true that in the end it’s overkill, but that’s better than underkill. I’d rather be the limiting factor on my motorcycle, rather than outclassed technology.
    I don’t have much interest in hopping up my R90 performance-wise, (I will always be bringing up the rear), but I’ll readily spend money on brakes and suspension. With modern cars and their operator’s driving habits, they’ll run me over without a second thought, given the chance.

    I see brakes and suspension as my attempt at an insurance policy.

    (Oh, and could we please type quietly? No need to use a bullhorn. :augie)
    #30
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  11. Wirespokes

    Wirespokes Beemerholics Anonymous

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    It seems the make/break point is where you lose traction. I've never tried to skid the front tire, but then again, I don't think I've ever used all the brake available, and I've panic stopped a few times. Maybe two large people traveling with a ton of gear (worst case) could utilize that system, but I doubt a solo rider of my size would ever need that much.

    I don't disagree that it's nice having a lot of brake at your disposal (I've always subscribed to the view of having lots in reserve, whatever it is). I'm just trying to let others know that it's not necessary to spend $800 to have better than acceptable two-finger ATE brakes.
    #31
  12. bpw

    bpw Been here awhile

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    Most decent disc brakes can lock up the front wheel, but better brakes allow way more control since you don't have to squeeze as hard. We can be a lot more sensitive with our brake modulation when pulling gently than hard.

    The really, really powerful brakes on my Aprilia are a lot easier to use at max without locking up than the stuff on my vintage bikes, even though the vintage bikes will still lock up the tire if you try hard enough.
    #32
  13. airheadPete

    airheadPete Wherever they send me. Supporter

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    Good point.
    I’ve upgraded the brakes on my ‘92 Yamaha FJ1200 recently to R-6 blue spots, FZ-1 master, Galfer rotors and HH pads.
    Wheel lock-up point is the same, but it’s been much easier to scrub off speed by just thinking about it and a light touch, instead of grabbing the lever and yanking it back. With more power came better control. :nod
    #33
  14. Wirespokes

    Wirespokes Beemerholics Anonymous

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    That's a good point about the bigger brakes being more controllable. Bigger brakes also won't fade as quickly. But I still say that reducing the stock MC size gives much better control of the stock system. The early airheads were at the infancy of motorcycle disc brakes and the engineers routinely spec'd master cylinders that were too large. As the years passed, master cylinder sizes came down. So if you think the engineers knew best, think again. They certainly changed their tune over the years.
    #34
  15. Big John Sny

    Big John Sny Long timer

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    going down 1 mm makes a huge difference in force actually. the force multiplication is the area ratio. dropping from 14 to 13 mm is 154 mm to 132 mm, say you are pushing a 40 mm piston (1256 mm) that is 8.2:1 vs 9.5:1
    #35
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  16. bmwrench

    bmwrench Long timer Supporter

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    I've never done it on purpose, but have done so accidentally. I hit a patch of sand under hard braking at a good speed. The front end went into a wobble, and the bike wanted to fall down right now. I still don't know how I saved it. No wheel rotation=no gyro.

    I've often thought that the manufacturers were training us by not giving us too much power with early discs.
    #36
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  17. Piggdekk

    Piggdekk love speed, hate rush

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    on my r100s I rebuilt calipers, the under tank MC and put braided brake lines. Still the most effective improvement on brake feel has been a new cable (from the lever to the MC). The old one wasn't broken or ruined, just old and I suppose the actual cable didn't slide too well under pressure in the sleeve. In my experience the cable is too often underlooked, and it's not too expensive to change. I can definitely notice the difference when I ride other airheads with an old cable, am I the only one?
    In insight I would also try a smaller MC, but I feel safe enough with the current system, my next constraint to pull stoppies is the front fork.
    #37
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  18. RGregor

    RGregor Been here awhile

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    I have. A Magura throttle grip combined with a Brembo pump and the /5 controls.

    Right_controls.jpg
    #38
  19. kcoralj

    kcoralj Been here awhile

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    When I repaired/upgraded my r65 brakes I replaced the master cylinder first, dropping down from 16 to 15mm, then after I determined that the calipers were corroded and too expensive to repair I adapted a set of four piston yamaha calipers and larger floating discs. The 16mm would have been the best ratio with my new calipers but I'm not going to change it out.
    They are very strong with a light feel but also very controllable, just a few practice stops and you can get a good feel for the traction threshold.
    I don't think anyone would have a problem dropping the master cylinder size, the lower effort allows more precise control.
    #39
  20. bodine003

    bodine003 Long timer

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    BMW GA.JPG Fixed my front brake with a 2000 HD Dyna Sport dual disc front end. high end Showa with comp & rebound damping. GMA 5/8 bore M/C.
    not too many 76 R75/6 that can do stoppies!!
    #40
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