Making A Right Fork Leg For Dual ATEs

Discussion in 'Airheads' started by disston, Nov 3, 2011.

  1. daveoneshot

    daveoneshot Been here awhile

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    Yo, Kai Ju,any chance of a picture of your M/C banjo lines ?? I would like to do the same brake mod to my R 100/7 and could use some more education ....sources for the fittings, and any special tweaks I should know, thanks, Dave.
    #21
  2. Wirespokes

    Wirespokes Beemerholics Anonymous

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    Oh, but they do have a function! They keep the caliper from flopping up or down. The caliper also swings, and has to slide easily on those 'wings'.
    #22
  3. Stan_R80/7

    Stan_R80/7 Beastly Gnarly

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    On my /7 left front fork, the tangs look like they hold the outer pads in place. But, there is a gap between the pads and tang, so it is not clear at this point how much of the tang is critical. Both an upper and lower tang need to be moved.

    Upper tang:

    [​IMG]

    Lower tang:

    [​IMG]
    #23
  4. AntonLargiader

    AntonLargiader Long timer

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    Look at how the pad is mounted to the caliper, and imagine the braking forces, and then it will be clear.
    #24
  5. Stan_R80/7

    Stan_R80/7 Beastly Gnarly

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    Upon closer examination in the light of day, the lower tang has 0.011" clearance to the pad but the upper pad touches the upper tang. Thinking about reaction forces, the upper tang takes the rotating force from the disc to the pad. Good to know before modifying anything.
    #25
  6. Kai Ju

    Kai Ju Long timer

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    Here you go. Be aware that the banjo bolt setup needs to have a flat surface on the master cylinder to seal. I did mine with a file. I crammed a short rubber plug into the hole and then used a file to level out the seal surface on the master cylinder. I verified it's flatness and squareness by using a thick spacer over a 10x1 mm bolt. I screwed it in the hole and then checked for airgap with the spacer seated on the master cylinder. Hasn't leaked, ever.
    Also, left and right caliper may look the same, but they are not. I bought a left caliper thinking it would be a straight install.:rofl
    The bleed nipple hole is opposite and it's machining is different from the hole for the compression fitting on the brake line.
    I was able to use a drill bit resharpened to match the angle of the bleed nipple seat surface and centered it in the hole with a bushing while I hand reamed the seat for the bleed nipple, sorry no pics of that process.


    Banjo bolt set up and hose routing

    [​IMG]

    [​IMG]

    Master Cylinder seal surface before filing

    [​IMG]

    After

    [​IMG]

    Caliper installed

    [​IMG]

    [​IMG]

    The brake hose was made for me by a local shop, while I waited :D
    He may still have the specs, cost was about $80.00 for the hoses, fittings and the rubber grommet for the brake hose in the stock guide.
    #26
  7. Wirespokes

    Wirespokes Beemerholics Anonymous

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    Something must have been weird with your second caliper - there are no lefts or rights. They're all the same. I've never had an issue with a caliper not working on a particular side. Also, if they were handed, I'm sure they would have been stamped or some indication would have been placed on them.
    #27
  8. Kai Ju

    Kai Ju Long timer

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    Next time you get the chance to look at one examine the bottom of the two holes. The one for the bleed nipple has a seat cut in it for the bleed nipple.
    Mind you, I just went to Max's Parts Catalog to prove my point with the part number for the right side being different from the left only to find out that it isn't.
    I know I didn't imagine the difference or I wouldn't have gone through the trouble of making the tooling for cutting the seat.
    At least I sure hope so................
    #28
  9. daveoneshot

    daveoneshot Been here awhile

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    Great pics and info about the brake job.....thank you, Dave.
    #29
  10. Kai Ju

    Kai Ju Long timer

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    You're welcome, glad to help.
    #30
  11. Wirespokes

    Wirespokes Beemerholics Anonymous

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    Guess I'll have to take a close like as you suggest. But I've never had a problem, and I've built a few of these and used left ones on the right side.

    Also I seem to recall both the hard brake line and the bleed nipple being roughly the same shape and angle on the end.
    #31
  12. Kai Ju

    Kai Ju Long timer

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    Sounds like you have more experience on this subject than me since I've only done one, mine.
    That makes me wonder whether somebody seriously overtorqued either one of the fittings on the used left caliper I bought. That may have resulted in the deformation of the seat. Since the bleed nipple is solid steel while the brake line is a compression fitting they may have left different witness marks.
    #32
  13. Wirespokes

    Wirespokes Beemerholics Anonymous

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    Yeah, I've done five or six of them over the years. The first one was my R90 back in 94. I totally forgot to check out one of the spare calipers, but I suspect your suspicion may be true.
    #33
  14. motoman711

    motoman711 n00b

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    I know this is an old thread but... can you tell me who your buddy in SanJose is? I would like to have him modify a leg.
    #34
  15. disston

    disston ShadeTreeExpert

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    I'm sorry to have to tell you that wirewrkr passed away sometime ago. May have been two years now or it's been close to two years at least. He was a really much loved very active member of this community.

    Maybe somebody else here will tell the name of a good machinist or even the one Robert knew in San jose. Where are you Motoman711?

    I think that most if not all the info needed to do the mod is in this thread. I was always the most proud of this one because it seems so simple. At least in principle.
    #35