My r90 restoration.

Discussion in 'Airheads' started by blaine.hale, Dec 29, 2009.

  1. Beater

    Beater The Bavarian Butcher

    Joined:
    Sep 3, 2009
    Oddometer:
    3,701
    Location:
    Atlanta, GA, USA
    Who undrilled these?!

    :lol3
  2. hardwaregrrl

    hardwaregrrl ignore list

    Joined:
    Jan 26, 2006
    Oddometer:
    8,176
    Location:
    Atlanta
    Have you adjusted the cam to center the caliper to the disc???
  3. blaine.hale

    blaine.hale Long timer

    Joined:
    Feb 28, 2009
    Oddometer:
    3,608
    Location:
    Atlanta, Ga
    I did upon the rebuild but it's something can circle back and check again.
    Yes, I have those lovely solid disks. Beater sold me a drilled one, I just need to blast it before it goes on my clean bike :D
  4. blaine.hale

    blaine.hale Long timer

    Joined:
    Feb 28, 2009
    Oddometer:
    3,608
    Location:
    Atlanta, Ga
    Haven't posted pics in a while. I don't have my camera equipment currently so here's some phone pics :)

    [​IMG]

    [​IMG]
  5. disston

    disston ShadeTreeExpert

    Joined:
    Mar 22, 2011
    Oddometer:
    12,373
    Location:
    Silver Spring, Md
    I have seen arguments that the solid rotors were just as good but I can't get over the way they look maybe. They just don't look as sure as a drilled disk. I think there is an advantage in the rain with drilled.
  6. crazydrummerdude

    crazydrummerdude Wacky Bongo Boy

    Joined:
    Nov 28, 2006
    Oddometer:
    7,927
    Location:
    El Segundo, CA
    :lol3
  7. Wirespokes

    Wirespokes Beemerholics Anonymous

    Joined:
    Jul 26, 2002
    Oddometer:
    8,725
    Location:
    Jackson's Bottom Oregon
    I want to see pix of you undrilling the new one.

    I like the solid discs because they don't score up like the drilled ones.
  8. blaine.hale

    blaine.hale Long timer

    Joined:
    Feb 28, 2009
    Oddometer:
    3,608
    Location:
    Atlanta, Ga
    Bout to take the r90 on this route for 2 weeks:

    <iframe width="640" height="480" frameborder="0" scrolling="no" marginheight="0" marginwidth="0" src="https://maps.google.com/maps?saddr=Laramie,+WY&amp;daddr=Sinks+Canyon+State+Park,+Sinks+Canyon+Road,+Lander,+WY+to:Whiskey+Basin,+Fremont,+WY+to:Grand+Teton+National+Park,+Alta,+WY+to:Yellowstone+National+Park,+WY+to:Bear+Tooth+Pass+Highway,+Cooke+City-Silver+Gate,+MT+to:Cathedral+Mountain+Ranch+Trail,+Nye,+Montana+59061+to:Glacier+National+Park,+West+Glacier,+MT+to:Banff+National+Park,+Banff,+AB,+Canada+to:Kikomun+Creek+Provincial+Park,+East+Kootenay+B,+BC,+Canada+to:Helena+National+Forest,+Helena+Valley+West+Central,+MT+to:Lovell,+WY+to:Laramie,+WY&amp;hl=en&amp;sll=45.95115,-109.742432&amp;sspn=5.392901,9.876709&amp;geocode=FYdcdgIdw860-Sl5m9qO94RohzGT5cSh98GJjg%3BFVFEjAIdUKSD-SEfY8DzAocQdylF_mD5-6lZhzEfY8DzAocQdw%3BFdN2lwIdO9N3-SmPHRbB1FtNUzHG23THhusotQ%3BFbXXnAIdIddm-SE3o5HMjrigpSmpG13JnlFSUzE3o5HMjrigpQ%3BFa7VpQIdsZRo-SG74Y80MPmorClVVVVVVeVRUzG74Y80MPmorA%3BFVSXrgId-L1z-SnZt9uNvvpOUzFKJ3ryizazyA%3BFaH4tAIdz7pz-SkXq1-OcGtPUzGNI5o0hArw2g%3BFe725wIdIr03-SHsXcUVIrwWrylVVVVVFZBoUzHsXcUVIrwWrw%3BFeXpDAMddokc-SHm18qsaOKdwCmVkZKMK2Z3UzHm18qsaOKdwA%3BFXtg7wIde24h-SG_R0mAWSRgHSknUKp3qgdlUzG_R0mAWSRgHQ%3BFQ4nygIdktZV-SGWPcr13QfEnilN28ftD1FDUzGWPcr13QfEng%3BFU0qrAIdRxuK-Slj4JrFQ2ZJUzHFP1u3mkupSQ%3BFYdcdgIdw860-Sl5m9qO94RohzGT5cSh98GJjg&amp;oq=145+Cathe+Trail+Nye,+Montana+59061&amp;t=h&amp;dirflg=h&amp;mra=ls&amp;ie=UTF8&amp;ll=46.286224,-110.874023&amp;spn=14.580236,28.125&amp;z=5&amp;output=embed"></iframe><br /><small><a href="https://maps.google.com/maps?saddr=Laramie,+WY&amp;daddr=Sinks+Canyon+State+Park,+Sinks+Canyon+Road,+Lander,+WY+to:Whiskey+Basin,+Fremont,+WY+to:Grand+Teton+National+Park,+Alta,+WY+to:Yellowstone+National+Park,+WY+to:Bear+Tooth+Pass+Highway,+Cooke+City-Silver+Gate,+MT+to:Cathedral+Mountain+Ranch+Trail,+Nye,+Montana+59061+to:Glacier+National+Park,+West+Glacier,+MT+to:Banff+National+Park,+Banff,+AB,+Canada+to:Kikomun+Creek+Provincial+Park,+East+Kootenay+B,+BC,+Canada+to:Helena+National+Forest,+Helena+Valley+West+Central,+MT+to:Lovell,+WY+to:Laramie,+WY&amp;hl=en&amp;sll=45.95115,-109.742432&amp;sspn=5.392901,9.876709&amp;geocode=FYdcdgIdw860-Sl5m9qO94RohzGT5cSh98GJjg%3BFVFEjAIdUKSD-SEfY8DzAocQdylF_mD5-6lZhzEfY8DzAocQdw%3BFdN2lwIdO9N3-SmPHRbB1FtNUzHG23THhusotQ%3BFbXXnAIdIddm-SE3o5HMjrigpSmpG13JnlFSUzE3o5HMjrigpQ%3BFa7VpQIdsZRo-SG74Y80MPmorClVVVVVVeVRUzG74Y80MPmorA%3BFVSXrgId-L1z-SnZt9uNvvpOUzFKJ3ryizazyA%3BFaH4tAIdz7pz-SkXq1-OcGtPUzGNI5o0hArw2g%3BFe725wIdIr03-SHsXcUVIrwWrylVVVVVFZBoUzHsXcUVIrwWrw%3BFeXpDAMddokc-SHm18qsaOKdwCmVkZKMK2Z3UzHm18qsaOKdwA%3BFXtg7wIde24h-SG_R0mAWSRgHSknUKp3qgdlUzG_R0mAWSRgHQ%3BFQ4nygIdktZV-SGWPcr13QfEnilN28ftD1FDUzGWPcr13QfEng%3BFU0qrAIdRxuK-Slj4JrFQ2ZJUzHFP1u3mkupSQ%3BFYdcdgIdw860-Sl5m9qO94RohzGT5cSh98GJjg&amp;oq=145+Cathe+Trail+Nye,+Montana+59061&amp;t=h&amp;dirflg=h&amp;mra=ls&amp;ie=UTF8&amp;ll=46.286224,-110.874023&amp;spn=14.580236,28.125&amp;z=5&amp;source=embed" style="color:#0000FF;text-align:left">View Larger Map</a></small>
  9. scoester

    scoester Adventurer

    Joined:
    Sep 28, 2009
    Oddometer:
    22
    Location:
    Montana
    You are about to ride through some of the prettiest country anywhere... My back yard. If you are coming through Butte, which it looks like you will be close. I would be happy to buy you a cold beverage.

    Have fun and have a great trip.

    :beer
  10. blaine.hale

    blaine.hale Long timer

    Joined:
    Feb 28, 2009
    Oddometer:
    3,608
    Location:
    Atlanta, Ga
    Thought you guys might like to see how the r90 is doing and where it has been.
    It's been carbon fouling the left spark like mad...my best guess is weak spark over there. I'm putting the points back on now to further bisect the issue. My Hoske exhausts arrived, just need to go pick them up and install them.
    Just got back from a 2 week trip through the rockies, check out all the pictures here:
    HALEMOTO TUMBLR

    [​IMG]

    *side note: I hate that front fender!
  11. blaine.hale

    blaine.hale Long timer

    Joined:
    Feb 28, 2009
    Oddometer:
    3,608
    Location:
    Atlanta, Ga
    I've got a line on r90s forks with calipers for mega cheap.

    Stay tuned to see if that works out and if I'll finally have sufficient braking!!
  12. disston

    disston ShadeTreeExpert

    Joined:
    Mar 22, 2011
    Oddometer:
    12,373
    Location:
    Silver Spring, Md
    That would be the primo score. Those units are getting rare. You may also want the 17mm undertank MC but the addition of a handlebar MC would be a step up.
  13. crazydrummerdude

    crazydrummerdude Wacky Bongo Boy

    Joined:
    Nov 28, 2006
    Oddometer:
    7,927
    Location:
    El Segundo, CA
    We're going to stay '74 R90 twins, then, because I have some dual-disc sliders/calipers in a box waiting to be a winter project. :lol3
  14. blaine.hale

    blaine.hale Long timer

    Joined:
    Feb 28, 2009
    Oddometer:
    3,608
    Location:
    Atlanta, Ga
    R90s fork legs are on their way along with 2 40mm ATE calipers l, all in great shape for $120 total.
    Looks like I may need a 17mm MC kit, a splinter and another stainless line to make this all complete....oh yeah, and one more drilled disk.
  15. disston

    disston ShadeTreeExpert

    Joined:
    Mar 22, 2011
    Oddometer:
    12,373
    Location:
    Silver Spring, Md
    There's a splitter on Ebay right now, was yesterday, for a buy it now price. I was tempted to get it but I'm pretty broke.
  16. chasbmw

    chasbmw Long timer

    Joined:
    Feb 19, 2006
    Oddometer:
    2,702
    Location:
    Bath Uk
    If you want brakes that work, either adapt your existing MC or best of all buy a 13mm twin throttle cable handlebar mounted MC. BMW were very conservative when designing the master/slave ratios, resulting in very wooden brakes, a 13mm is just about perfect for brakes that have feel and power.

    Charles
  17. blaine.hale

    blaine.hale Long timer

    Joined:
    Feb 28, 2009
    Oddometer:
    3,608
    Location:
    Atlanta, Ga
    I will never ever ever ever go to a handlebar mounted MC, I'm afraid.
    I don't like hacking up stock parts to make something work and still not look elegant or stock. I also don't weigh more than 125lbs, which means the 1 r90 disc brake isn't THAT bad, especially with braided lines, 40mm pot and a fresh master cylinder rebuild. The stock r90s set up should be fantastic :)
  18. Kai Ju

    Kai Ju Long timer

    Joined:
    Jul 29, 2009
    Oddometer:
    2,196
    Location:
    Long Beach, California
    Now that you've said that I'll chime in. Like you I didn't want to destroy the clean lines of the under tank M/C so I converted mine to dual disc by plugging two lines into the stock 14mm M/C. I used a banjo bolt instead of a compression fitting. I had to machine, read file, to get a good seal surface for the copper gasket but I'm very happy with the results.
    Lever is a bit soft but brakes come in early in the travel and feel quite strong and progressive.

    Here is a pic of the master cylinder banjo bolt setup:

    [​IMG]
  19. ontic

    ontic

    Joined:
    Jul 14, 2008
    Oddometer:
    1,317
    Location:
    Melbourne
    Fantastic is a relative term with airhead brakes...

    err, let me try that again..

    It is fantastic that I have twin Ate's on my R90 and it is also fantastic that you are about to have them. Dramatically improving brakes to 'sufficient' is fantastic.:D
    Given you are rebuilding the system at the same time I think you should be pretty happy- and probably end up with better brakes than me.
    On that note though, what rotors are you going to use? I love my rusty cast iron ones. They suit the charm of my 90.

    Me- if/when my undertank dual output master cylinder needs work I am probably going to switch to the handlebar master cylinder. I dont' mind hacking stock parts at all, and I am not drawn to keeping stupid stock systems (like the cable to undertank MC) just for the sake of keeping it stock. The only thing that needs to be hacked is the right hand lever/perch thing, and really, given that it wears out where the throttle cam gear sits, it is kind of a (long) service item anyway (and is still currently available new).
    No biggy for me, YMMV.

    My friend Charlie (the guy who drew up that great 74 90/6 electrical diagram you liked)(now Brun on adv) has done a handlebar mounted magura master cylinder on the /5 controls. Similar to what has been posted here before by others but a bit more refined and much nicer execution IMO. Looks fantastic to me. Elegant and good enough to be stock, I hope he posts some photos soon.

    Actual fantastic brakes? My hacked to buggery G/S with its full 'modern' (10 years ago is modern right?:D) KTM brembo master cylinder, braided line and (only two pot) caliper with a single 320mm rotor... now that feels fantastic. I don't need any more brakes than that thank you very much.

    My twin disc R90 does stop perfectly well and sufficiently when asked to, I just feel there is something (a lot) lost between the cable and hydraulic system.


    Anyway, you're bike is a beauty and I'm sure you're going to be really happy once you get them sorted.
  20. disston

    disston ShadeTreeExpert

    Joined:
    Mar 22, 2011
    Oddometer:
    12,373
    Location:
    Silver Spring, Md
    I regretted the suggestion of the 17 mm MC right away but it got away from me. I am always thinking the single disc MC isn't right for the dual set up. And I've finally come to realize that I've been wrong.

    It's true the stock BMW dual disk set up on the S and other Ate bikes with dual disks used a 17 mm MC. If you go smaller there will be firmer and better brakes. I'm afraid if I go too small there will be too much travel and this is the other side of the coin that can really cause problems. Some riders do use a 13 so the single disk 14 should be OK. I would still check carefully. If you have warped disks the lever travel will be more and too small will be a problem. Since you already have the 14 I'd try to use this. Then you'll know where you want to go from there.

    I like Kai Ju's twin hose set up. Much neater and less space than a splitter.