An Unholy Union V: DRZ forks on an Airhead

Discussion in 'Airheads' started by Ras Thurlo, Jun 28, 2014.

  1. Jim Day

    Jim Day full manic mechanic

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    Lock or stops?
    #41
  2. Phreaky Phil

    Phreaky Phil Long timer

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    Steering lock. When the DRZ clamps are used on the Beemer the forks hit the tank first and if that is modified or a different tank used then the clamps hit the frame. At this point there is still way less steering lock than with the original forks. Prusters clamps will help with getting more lock. I'm not sure if it will be as much as the originals as the airhead has an exceptional steering lock ( small turning radius )
    So long as it is better than a KTM 990 :D
    #42
  3. Jim Day

    Jim Day full manic mechanic

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    Yeah no doubt.

    DRZ forks are tighter to the headset and the standard stop on the frame wont work with the stops on the DRZs triple. Essentially if you leave it stock the fork tubes smash into the tank.

    Most guys just get around this by welding some steel on to the original frame stop but.....with my build I decided to put in adjustable stops on the triple leaving the frame alone.

    Here's the pics...
    [​IMG]

    [​IMG]

    Pretty self explanatory I drilled into then tapped the stops on the forks. I then threaded in a 1/4 20 bolt and can adjust the stop and the fork to tank clearance.

    What's really cool is you can adjust these even after everything is put together.
    [​IMG]
    #43
  4. Ras Thurlo

    Ras Thurlo Desert Lion

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    this guy may lack taste in music, but he has style


    <object width="420" height="315"><param name="movie" value="//www.youtube.com/v/NZv0dUsXW_8?version=3&amp;hl=en_US"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="//www.youtube.com/v/NZv0dUsXW_8?version=3&amp;hl=en_US" type="application/x-shockwave-flash" width="420" height="315" allowscriptaccess="always" allowfullscreen="true"></embed></object>
    #44
  5. Prutser

    Prutser Long timer

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    It looks like the triples will have two degrees less steering lock than the stock G/S without touching the tank.
    If you would not mind to modify the tank you will get even more than the stock G/S triples.

    We might be able to mount a set in a GS next week so than we can tell more about the steering lock on those frames.
    #45
  6. Phreaky Phil

    Phreaky Phil Long timer

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    Looking forward to seeing how they are in the GS frame :D
    #46
  7. Ras Thurlo

    Ras Thurlo Desert Lion

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    FYI

    may be more indicative than accurate, but interesting nonetheless

    its always the last few degrees that make all the difference, both for city traffic and for doubling back on tight trails

    #47
  8. Prutser

    Prutser Long timer

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    It looks like this...

    [​IMG]

    I didn't use the washer under the top nut because I made a temporary stem out of an old KTM stem which was a bit short.

    The top and bottom pictures also shows the holes to bolt something like this onto the triple :evil

    [​IMG]


    [​IMG]
    #48
  9. Phreaky Phil

    Phreaky Phil Long timer

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  10. Screaming Chicken

    Screaming Chicken Long timer

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    I may have just bought this... :evil

    [​IMG]

    I guess that's one way to find out if it'll fit the PD fairing... :rofl
    #50
  11. Prutser

    Prutser Long timer

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    That didn't take you very long :lol3
    #51
  12. jellycow

    jellycow NX NX NX NX NX NX NX NX NX

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    Yeah, get going man! And keep us upposted.


    I should continue on my GS as well, house rebuilding, a 1.5 year old and a pregnant wife about to pop do take up so much time :huh
    #52
  13. Screaming Chicken

    Screaming Chicken Long timer

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    What you don't see is the months of hemming and hawing, drooling over pictures, weighing all the pros and cons and unknowns and all that...

    And then you talk to this guy who knows some stuff about suspension and have a look on the obvious website a day or two later and hey look there's one for sale, oh hell why not. :rofl

    It's a nice complete set anyway, though I will have to do something about the brake. Does that suzi caliper work with the GS master cylinder or are there better recommended combinations given that I'm used to 320mm plus four-pot brembo...
    #53
  14. Prutser

    Prutser Long timer

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    I guess you will mis the 320 rotor. But there should be some oversize brake kit's available for a decent price.
    If your stock master cilinder is 12mm (which it is not) it should work. Better would be an 11mm but as far as I know bmw never made them.
    The 12mm master cilinders were used on R80ST's
    Using a12mm cilinder makes the brake feel way to firm so you won't really feel what your doing.

    Dmaster made the Drz master cilinder fit on the bmw set-up. But that involves some welding but works great.
    #54
  15. Udo

    Udo Been here awhile

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    Here is more progress on my 81 R80G/S project. I used HPMGuy's 50mm triples, shimmed them down to the DRZ 49mm tubes. I'm liking it so far.

    Attached Files:

    #55
  16. Phreaky Phil

    Phreaky Phil Long timer

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    Without the gull wing bottom clamp, do the forks come up and hit the bottom clamp ?
    #56
  17. Phreaky Phil

    Phreaky Phil Long timer

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    The DR 650 and DRZ 400 have the same caliper but the 650 has a 1/2" master cylinder which would be 12.7mm and the DRZ an 11mm. The DR650 has a much bigger disc though. On my DR650 with the DRZ front end I left the stock DR master cylinder and caliper with the smaller DRZ disc rotor and the brake wasnt as bad as I thought it would be. I now hav a 320 for it for when it goes on the Beemer.
    Will have to have a look for a smaller master cylinder for the GS. It is 13mm.
    #57
  18. Prutser

    Prutser Long timer

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    The way David fitted his oem drz cylinder works really great but its a tricky job. I will post some pictures later.

    What would be even better is if there would be brackets available to mount BMW (brembo) F or G650 calipers onto the drz forks. Those work great with the BMW 12mm master cylinder.
    #58
  19. Phreaky Phil

    Phreaky Phil Long timer

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    Can you get a 12mm for the R80/100 GS ?
    Or find another throttle to use and run the DRZ 11mm mastercylinder. Wouldnt be able to get a dual cable setup. Yours is a single cable throttle ? what do you use to join them to a twin cable ? a choke cable joiner ?
    #59
  20. Prutser

    Prutser Long timer

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    I didn't think about the later trottle body... Getting a 12 mm for those could be hard if not impossible.
    The G650 trottle is a single cable one. But with a bmw cable splitter I can use original cables going to the carbs and a modified G650 trottle cable on the top. I always try to use as much stock parts as possible because I hate it when things are getting harder to replace than the stock items.

    I might start looking for a 11 or 12mm piston to use in a stock master cylinder so we could make a big one smaller.
    They would have to come out of a rear cylinder I guess because i haven't seen the 11mm in any bmw front ones.

    You could also turn your bike into a double disk set-up :evil Than you can use a bigger diam master cylinder again.
    Allready done it on a Harley :D just use two left fork sliders and make a bracket, for the calipers.
    F800GS or 1200GS hub and your done:lol3

    [​IMG]
    #60