BMW r90/6 cafe racer build

Discussion in 'Airheads' started by Hearse, Nov 10, 2012.

  1. Hearse

    Hearse Project n'gagi

    Joined:
    Nov 7, 2012
    Oddometer:
    148
    Location:
    sydney
    Hey guys,

    How's it all going?

    I am new to the forums in a registered member sense, but I have been lurking often in forms of research for my bike before buying it.

    Quick run down:
    26 years old
    live in Sydney
    currently ride a '06 VTR1000f which I love, man I love Honda's
    just purchased my 1975 BMW r90/6 which I am going to do a full strip/rebuild in to a cafe racer

    So this is my bike on its way home:
    [​IMG]
    [​IMG]
    [​IMG]
    The bike itself is in mechanically really good condition, engine is strong as, and the only leak is the one fuel tap...hopefully it stays that way :) cosmetically it needs love, but thats why I got it, it would be boring otherwise!

    Bike set for tear down
    [​IMG]

    Bike stripped down:
    [​IMG]

    Looking over the frame this is the worst of the rust which was located under the master cylinder
    [​IMG]
    What I plan to do:
    - repaint the frame/sub-frame/drive shafr with 2pac paint
    - aqua blast engine and gearbox to shine it up
    - build own bubble cowl for the rear and have a crack at building a seat as well
    - repaint tins and newly constructed cowl with 2pac paint

    Questions I have
    - the front and rear fenders are fibreglass, do you guys paint strip/prep/paint or sand/prep/paint?
    - that damn master cylinder - which master cylinder from which bike will suit a handle bar relocation? which one have you guys used?
    - is it worth updating all of the ignition gear? coils etc?
    - I am looking at rebuilding the front forks and carbies where can i get rebuild kits? anywhere in Australia?
    - I want to put some rear sets on, I have some bolt on kits on the net, they look the goods or is there any better ideas?

    I will do my best in keeping this thread updated with the bike build, but I am really going to take my time and do this nicely to one sweet ass build

    Thanks guys!

    Cheers,

    Warren
    #1
  2. Hearse

    Hearse Project n'gagi

    Joined:
    Nov 7, 2012
    Oddometer:
    148
    Location:
    sydney
    $1000 order placed in to motorworks.co.uk for a bunch of gear :evil

    Engine removed from frame, frigging finally! Effort :)

    Any hints for:
    - master cylinder relocation to handle bars? Which master cylinder to use?
    - how to clean engine? Bead/aqua/soda blasted?

    Next step: build the rear seat cowl out of fibre glass then prep parts for paint :)
    #2
  3. gsd4me

    gsd4me 90% bluff

    Joined:
    Dec 11, 2005
    Oddometer:
    7,944
    Location:
    Brisbane, Australia
    DON`T DO IT!! It would be criminal to destroy a complete and nice looking bike to turn it into a shitheap.
    #3
  4. Hearse

    Hearse Project n'gagi

    Joined:
    Nov 7, 2012
    Oddometer:
    148
    Location:
    sydney
    Ah man, wet blanket! ;)

    I'm not cutting/welding anything and keeping all stock parts so it can easily be returned to stock with no hassle :)
    #4
  5. awaffa2003

    awaffa2003 Adventurer

    Joined:
    Jun 12, 2010
    Oddometer:
    43
    Location:
    Northern Illinois
    I swear, every time I see crap like ^ that I want to strangle somebody. It's YOUR bike. YOUR vision and YOUR masterpiece. Do what YOU want with it, don't let anybody tell you that you shouldn't. Some people feel the need to go above and beyond constructive criticism and start bashing. I wish somebody would call my modified airhead a shitheap to my face...I feel better now lol.

    Now to address what you've been asking, I need to ask you something, how radical to you want to get with this? As for your master, you could go OEM BMW with integrated handlebar controls. For your single disc set up, I'd go with a 12 or 13 mm master, look on ebay for them. Or if you're not happy with your brake performance, you could easily get another fork bottom with the ATE caliper mount and go for dual discs. I'm actually looking at going a step further and not only upgrading my master to a newer Brembo radial master, but adding a second disc and fitting 4 pot oilhead calipers or even some 6 pot Tokicos. You can find the stock masters on motobins here http://www.motobins.co.uk/bmw-parts.php?model=R%20Series%202%20valve%20Twin go to Handlebars & Levers/Assemblies.

    And personally, I've never really cleaned my cases to the point of getting them blasted. I've used alot of engine degreasers and cleaners that do quite the job. Thing is, I feel like when the engine and trans get blasted, they look awesome, but they can be two different shades of aluminum where if they're just really clean, they have the same shade of almost clean. If I were so inclined, I'd get them bead blasted.

    As for your ignition, you can stick to stock points, or go electronic with Dyna III. Even going for Dyna coils would be an improvement.

    Good luck man, keep the questions coming and the knowledge flowing!
    #5
  6. Geeto67

    Geeto67 Adventurer

    Joined:
    Nov 8, 2012
    Oddometer:
    25
    Location:
    New Yawk Friggin City (and wadda YOU lookin' at?)
    I hate it when people think a cafe racer is just a set of bars and a seat. Nobody thinks I can turn an r1 into an adventure bike just by putting on some nobbies, so why think that about a vintage performance motorcycle and some shitty handmade parts.

    If you are going to "build" a bike, then really improve it. Solve the problems the stock chassis has, make it really fun to ride, not just something to impress high school kids with in parking lots.

    There is a little place called ritmo sereno in Japan that can sell you anything you want to make your bike look good in a weekend. But without the mechanical improvements you are just a no-go showboat. If you look at the bikes they build as showpieces - lot of big stick to back up their looks, case in point:

    http://www.bikeexif.com/bmw-r100


    Read the write up and see how much went into making this bike.


    Anyway, for a good starting point with any performance machine is to look at he race bikes of the same type. After all you are building a race bike for the street. Start with the Daytona winning 1976 r90s of Steve McLaughlin.
    #6
  7. kaput13

    kaput13 gasoholic

    Joined:
    Nov 20, 2010
    Oddometer:
    668
    Location:
    South Florida
    Hi Warren, chop, cut, weld, beat on, and modify to your heart's content. Looks like you got a nice example to keep your VFR company.

    Sand, prep, paint only worked great for me but I am sure there will be other opinions.

    Handlebar master cylinder plus extra front disc from a later airhead.

    Keep points and add an ignition booster.

    Don't know about rebuild kits in Australia. Lots of sources on this side of the world.

    Take a look at the rearsets made by inmate owner of Boxer Metal - nice.
    #7
  8. Hearse

    Hearse Project n'gagi

    Joined:
    Nov 7, 2012
    Oddometer:
    148
    Location:
    sydney
    Kaput and Awaffa thanks for the support I appreciate it. I have my daily in the VTR so I am really looking to have fun with this bike - I am going to do the bike proud dont worry :)

    I am going to go hard out with the rebuild eh, all new stainless bolts/washers/nuts, new bearings, everything that was painted gets repainted...and if money permits - engine rebuild (but its strong now so no hurry on that)

    Thanks for the advice on the master cylinder and the fibreglass prep - I will hop on fleabay and get that master cylinder sorted

    I got the engine and frame separated (as earlier stated)
    [​IMG]
    [​IMG]

    A couple more updates coming up, when i get my parts from the UK i will post a cheeky pic
    #8
  9. Big Bamboo

    Big Bamboo Aircooled & Sunbaked

    Joined:
    Sep 29, 2010
    Oddometer:
    8,309
    Location:
    Big Island of Hawaii
    I've read somewhere that the "fiberglass" fenders etc on these bikes are a material that contains a mold release agent, so if you sand down past the original finish you will need to clean the parts with a solvent prior to painting.
    #9
  10. Hearse

    Hearse Project n'gagi

    Joined:
    Nov 7, 2012
    Oddometer:
    148
    Location:
    sydney
    Sweet thanks Bamboo - I'll keep that in mind. So excited for this build - having a heap of fun with it already and I am only stripping down!

    Ah yea I will be getting those rear sets from Boxer Metal - are they still $300 for inmates :D
    #10
  11. Boxer Metal

    Boxer Metal Mad Scientist

    Joined:
    Nov 3, 2003
    Oddometer:
    3,609
    Location:
    Chico, California
    Just ask me:D
    #11
  12. adrenal

    adrenal skrunkwerks.com

    Joined:
    Jun 12, 2008
    Oddometer:
    681
    Location:
    Melbourne, Australia
    hey hearse, fricken go for it mate. let your creative juices run free!
    Nice bike. Was it advertised?
    I get lots of parts from Munich Motorcyces in Perth - they've pretty much got everything.
    Quick turn around where ever you are. Best to ring them.

    http://www.munichmotorcycles.com.au/
    #12
  13. Hearse

    Hearse Project n'gagi

    Joined:
    Nov 7, 2012
    Oddometer:
    148
    Location:
    sydney
    Haha I.didn't want to be too forward...but ok...are they still $300 for us? :D what would the damage be on postage to sunny Australia? Cheers mate!

    Thanks mate, I'll check em out...see how prices compare to our pommie mates. Yea it was advertised in gumtree, picked it up, got a few thumbs up on the way home - cheering...that's when I knew I made the right choice :)
    #13
  14. Hearse

    Hearse Project n'gagi

    Joined:
    Nov 7, 2012
    Oddometer:
    148
    Location:
    sydney
    NVM - I'll just get a Benji bucket or make one myself...she'll be right.

    Ah yea, I'm digging the idea of a taco/Speedo/headlight combo..our just Speedo combo like the r75?

    Any suggestions on a good one to put on my r90?

    Cheers
    Waz
    #14
  15. Boxer Metal

    Boxer Metal Mad Scientist

    Joined:
    Nov 3, 2003
    Oddometer:
    3,609
    Location:
    Chico, California
    Just sent you a Private Message regarding the rear sets
    #15
  16. Hearse

    Hearse Project n'gagi

    Joined:
    Nov 7, 2012
    Oddometer:
    148
    Location:
    sydney
    Hey guys,

    dont shoot me - i know i need to update more...but anyways.

    So i have been doing a bunch of cleaning and shaping.

    First - the engine! ... that damn engine!

    So i have used soda blasting...first i built a soda blasting "cabinet" that has been proudly sponsored by Riverbed ;-)
    [​IMG]

    [​IMG]

    the engine was filthy...
    [​IMG]

    and i tried it out on the filter cover just real quick - see if this all worked (never done ANYTHING like this before)
    [​IMG]

    in comparison it works pretty awesome, and that was just a quick blast, so after a real good working over it looks great, ill have to grab a photo tomorrow with no soda residue on it, but here is a sneak peak
    [​IMG]

    pretty bad ass result eh - but ill get a better pic tomorrow.

    Then i moved on to the wheels - man they are a mess...anyways,

    rear hub before:
    [​IMG]

    and after a working over:
    [​IMG]

    and the side of the hub:
    [​IMG]

    and after:
    [​IMG]

    so it appears i am getting the hang of it! I need to replace all of the bolts to stainless so it looks better and i have new sets of spokes to respoke the wheel (also something i havent done before!)

    next post...seat cowl
    #16
  17. Hearse

    Hearse Project n'gagi

    Joined:
    Nov 7, 2012
    Oddometer:
    148
    Location:
    sydney
    and the seat cowl!

    So i have just completed the plug for the seat cowl - i was heaps nervouse initially but after i got it taped up i was stoked how well it went.

    So first i got the frame built and some plant foam in place (sizing it up)
    [​IMG]

    Then i started shaping it up:
    [​IMG]

    ...and pretty much shaped:
    [​IMG]

    then i put some builders bog over it (one of THREE layers..)
    [​IMG]

    after about 5 hours of bog/sand/bog/sand etc...
    [​IMG]

    so after wraping the plug in painters tape and a layer of wax (bunch more layers of wax tomorrow and then 1:1 of PVA glue/water before fibreglassing)
    [​IMG]

    so i will be fibreglassing this week - get my seat cranking!!

    here is my little store room with a little work bench :)
    [​IMG]
    #17
  18. Speed King

    Speed King Long timer

    Joined:
    Oct 20, 2008
    Oddometer:
    1,667
    Location:
    Omaha
    Great project, great work.
    #18
  19. Hearse

    Hearse Project n'gagi

    Joined:
    Nov 7, 2012
    Oddometer:
    148
    Location:
    sydney
    seat cowl is complete (to an extent)

    So I glassed the cowl with 4 layers of FG...

    [​IMG]

    [​IMG]

    [​IMG]

    Then when that finally set, i removed the mould from the plug:

    [​IMG]

    [​IMG]

    not with out spilling some claret - this is it cleaned up, it bled a lot OK :lol3

    [​IMG]

    and a bit of trimming to make it look better:

    [​IMG]

    [​IMG]


    Next step is to high fill the mould ready for primer and paint
    #19
  20. Hearse

    Hearse Project n'gagi

    Joined:
    Nov 7, 2012
    Oddometer:
    148
    Location:
    sydney
    so the seat has been high filled to make it as smooth as I can, 4 layers of primer has been layed on it and its ready to be sanded/painted...stoked. I will make the seat for it later and wrap the seat cover around the bottom of the seat and rivet it along the side to finish it off.

    [​IMG]

    [​IMG]

    Next step is to prep the tank and my fairings (im using the stock front fairing but i need to find a replacement rear fearing, i dont want the stock one (goes up under the seat) does anyone know of a fairing that will fit the bike that i could replace it with? i was thinking of just taking the width of the fairing and radius and find one that will fit at the wreckers.

    the tank stripped and looking like it needs some love

    [​IMG]

    [​IMG]

    the old tank badges retired from its duty

    [​IMG]

    do you guys think that i should put my nose fairing on? i think i should - it would look pretty bad ass all painted up and mounted

    [​IMG]
    #20