Reincarnating an 81 R100RS

Discussion in 'Airheads' started by theDQG, Oct 1, 2017.

  1. theDQG

    theDQG Been here awhile

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    Hi all,

    New to this forum. My name is Arthur and I picked up a non-running '81 R100RS from a PO who bought it off a PO who kept excellent maintenance/repair records that showed competent maintenance. Unfortunately the 2nd PO kept none and when I asked him detailed questions (2k O-ring, spline lube, circlip, etc) his eyes just about crossed, but I was able to knock over 1k off the selling price and brought home a bike which I think has a good foundation to build on.

    I am definitely not taking a chance on the motor, transmission, and final output and will have all that overhauled.

    Here it exists, mid-dismantling, I am parting out plenty so if you need anything, just ask.

    I am selling the complete fairing, sides, gas tank, and seat all together to someone who wants to restore a R100RS to OEM. I don't want to part out anything from this group since they're all the same color/style.

    front.JPG LS.jpg RS.JPG
    #1
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  2. theDQG

    theDQG Been here awhile

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    Some inspirations I'm drawing from:

    UMC-1-700x466.jpg bmw-r100rt-1.jpg troydon_BMWR756_after-1024x525.jpg
    #2
  3. theDQG

    theDQG Been here awhile

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    I really like the machine look of the UMC build (top pic), and am thinking I'll run with that and go with a scrambler look and copy the top end of Bill's excellent build.

    Satin Black for some reason, to me, is just so BMW.
    #3
  4. Steve in OC

    Steve in OC Been here awhile

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    Hold on there before you dismantle it any further.

    Did you ride the bike for awhile and get a good read on its condition? Did you run the usual tests that determine the need for a rebuild (i.e. did you check for excessive play or noise in the trans and final drive, were there many missed shifts and/or false neutrals, is the motor burning oil, does it have low oil pressure or low compression, etc.)?

    Generally speaking, the PO's cluelessness about maintenance, by itself, doesn't justify rebuilding the motor or any other parts. You should make that decision only after you've run the tests and have found that it doesn't meet specs.

    BTW, welcome to the forum!
    #4
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  5. Medicine Hawk

    Medicine Hawk Adventurer

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    Sorry but I have to agree.

    Jumping into a custom build without determining how strong the foundation is... :confused Believe me, you just don't need those kinda headaches and disappointments. :baldy A tranny rebuild? $100+++ An Engine rebuild? $1000++ easy. Oh... And don't forget the REST of the bike!

    Reassemble the bike far enough to be ridden and then ride it for a few hundred miles. After that, you'll have some solid ideas of what you want from the bike, what the bikes capable of delivering and whether you can get what you want, from what you got.

    When I built my Hot Rod I started out with my high mileage R90 and then bought an ugly but fine running R100RT. That $1200 RT not only gave me something to ride for a while but also became the bones of a very nice customized scooter.and in the end saved me a fortune.


    Of course YMMV, so have fun!

    KenHawk
    #5
  6. ME 109

    ME 109 Long timer Supporter

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    Capability is generally not a consideration with a cafe.
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  7. Medicine Hawk

    Medicine Hawk Adventurer

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    Yeah well... I was also kinda hoping that after riding his bike for a few hundred miles he'd understand how... Uh.... Wasteful... :lol2 turning a nice Airhead into "Just another so-called Cafe Racer", to park in front of someone else's Coffee House".

    And yes, from what I could see in the photos, our new guy is stripping down a pretty nice looking bike.

    KenHawk
    #7
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  8. bajaburro

    bajaburro Ancient Adventurer

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    Can't get into this hack and slash paint it flat black stuff.
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  9. CafeDude

    CafeDude Ride to eat.....

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    Welcome to the asylum, Arthur! Probably not what you want to hear (especially from someone with my username....which has NOTHING to do with cafe'ing motorcycles, BTW), but if the bike is numbers matching and has all of the bits that make an RS an RS, then it's a shame to molest it. Even though it's an '81 transitional year (which many will say was the worst model year for BMW), it's such a shame to see another one lost to the sawzall.

    That said, perhaps the OP won't "hack" it up beyond it's ability to be returned to its former glory one day once it's limitations are realized.

    Anyway, none of my business, but this is the interweb, so on with the show!
    #9
  10. ME 109

    ME 109 Long timer Supporter

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    Clearly "many" don't have a clue. :1drink
    #10
  11. CafeDude

    CafeDude Ride to eat.....

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    LOLOL
    #11
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  12. Brun

    Brun Been here awhile

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    Welcome aboard, Arthur. You've probably gathered that chopping up good stock airheads doesn't go down too well with some here. Other, typically younger inmates will love what you are doing. It's your bike and you have the right to bend it to your will. The inspirational pics you show are sufficiently tasteful IMO.

    A suggestion: If you can possibly arrange it you will gain some kudos from ensuring that whatever you do is reversible. Your bike may still be alive after you are dead.

    My small gripe with cafes, bobbers, rats etc is that most can't be ridden in the wet due to the lack of useful mudguards (fenders). That puts their riders into the "fair-weather" class (not quite 'manly'), though I guess if a chap were to appear at the cafe with rich muddy stripes on their expensive leathers that could be different. Grin.

    Have fun and learn everything you can about your bike.
    #12
  13. BicyclebBob

    BicyclebBob Been here awhile

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    Chop it up have fun with it, weld some stuff on the frame! Don’t paint it flat black though, it always ends up looking cheap.
    Well the weather here in California is always fair and I feel like most people at least that I know have other more practical bikes as well as their cafe or bobber. I avoid the Starbucks too many bmw’s laden with touratech cases and old guys dressed head to toe in neon reflective suites showing off their iron butt patches pretending they’re on the long way around instead of a 600 mile jaunt with their thousands of dollars of adventure gear.
    #13
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  14. ME 109

    ME 109 Long timer Supporter

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    :y0! Paint it flat black! It isn't the paint.
    #14
  15. 100RT

    100RT Long timer

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    Wish I had known that the 81 was a bad year before I bought one 20 yrs ago! Still makes me smile when I ride it (172K)
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  16. theDQG

    theDQG Been here awhile

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    Thanks all for your welcome. I have read all the posts and will take heed of the advices and suggestions given.

    I hadn't thought about it, but now that it has been mentioned a few times, I'll make sure this bike is reversible in case I end up expiring before my "use by" date.

    The only major frame adjustment I would be making would be to the seat area and that's fortunately detachable. And I'll definitely put in a rear fender that goes all the way down, to protect the engine.
    #16
  17. ME 109

    ME 109 Long timer Supporter

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    Apparently the front forks are not so good on the '81 either.

    #17
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  18. theDQG

    theDQG Been here awhile

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    Don't worry, I don't hang around no starbucks.
    #18
  19. nmalozzi

    nmalozzi airheaded

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    Your bike your rules. I wouldn't cut up an RS, but that's just personal opinion. Just hold onto all the RS bits. The nay-sayers will become real friendly when you sell them a fairing part at a reasonable price.
    #19
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  20. Arktasian

    Arktasian Lets call it Naturalized

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    Being an RS, transformation is allowable. Wouldn't be the case had it been an RT.:hide
    #20
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