An Unholy Union V: DRZ forks on an Airhead

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

  1. Phreaky Phil

    Phreaky Phil Long timer

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    Is a 12mm available that will fit a GS. Ive been looking at the online stores and have only found 13mm annd bigger.
    Cheers Phil
    #81
  2. jjwithers

    jjwithers Been here awhile

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    I'm about to put a set of YZ450F forks on a 70's airhead. I'm making a separate topic on it in the airheads forum. Please chime in if you guys have any advice!? thanks!

    -Josh
    #82
  3. Phreaky Phil

    Phreaky Phil Long timer

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    Probably some good info here for what you are going to do http://www.advrider.com/forums/showthread.php?t=738023
    #83
  4. Phreaky Phil

    Phreaky Phil Long timer

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    I was talking to my BMW guru mechanic today about master cylinders and he did some checking and it looks as though we ca get a 12mm piston that will fit so I stopped at the local brake shop and they made a call to the place that sleeves M/C's for them and they have a 12mm sleeve so its looking like a posibility that we can make a 12mm M/C for the late model airhead controls :D
    #84
  5. Screaming Chicken

    Screaming Chicken Long timer

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    Cool :D
    #85
  6. Harty

    Harty Bloody Good Bloke!

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    This is all starting to read like learning rocket science to me!! :eek1

    I'll start slowly! What forks do I go for, the E, S or SM(Have found a full decent set of SM's with yokes/clamps for £80)

    That will do for starters! :evil
    #86
  7. Screaming Chicken

    Screaming Chicken Long timer

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    Holy shit that was quick!

    Bought that same set (from a different seller - 20 euro cheaper - but it's all from Wuxi, China anyway) last wednesday. It's now monday and it's here already. Didn't even have to pay any customs tax either.

    *impressed*

    (Edit: Customs tax came later. Bastards.)
    #87
  8. Screaming Chicken

    Screaming Chicken Long timer

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    Should've kept my mouth shut. :lol3

    It doesn't fit. Either the disc is too big or the adapter too tight, either way the disc edge rubs on the inside of the adapter and locks the wheel if I do everything up tight. This won't shim out either.

    [​IMG]

    Let's see how China is at customer support... :1drink
    #88
  9. Prutser

    Prutser Long timer

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    That's the same problem that Ras his caliper mount had. I filed a bit out of the bracket and now its fine.
    #89
  10. Screaming Chicken

    Screaming Chicken Long timer

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    Ah that's what you did. Ras mentioned shimming, there's no way to shim this out, but filing bits off is obviously another story. :lol3 I'll have a go at that.
    #90
  11. Screaming Chicken

    Screaming Chicken Long timer

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    Right. Caliper's on. Bit of action with the file, piece of cake. :D

    (Forgot how much of a pain those Nissin slidey calipers are if you're used to nice fat Brembos. Bit of a puzzle to get it all back together again with the clips and the sliders and all that. Though it seems they have improved somewhat compared to the horrible Nissin on my dearly departed Dominator.)

    So, head bearings. I noticed one of the nearby bike shops has DRZ head bearings at a discount, nice timing, but I've never heard of the brand (RMCP) and the first hit on Google is that same nearby shop so probably some cheap dodgy knockoffs best avoided. :lol3 Anything in particular to get (like SKF?) or just the Suzuki ones?
    #91
  12. Phreaky Phil

    Phreaky Phil Long timer

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    I picked up my master cylinder from the brake shop today. Successfully fitted a 12 mm sleeve to my 13 mm GS m/c. Now to order a piston kit
    [​IMG]
    :D
    #92
  13. Prutser

    Prutser Long timer

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    Thats looking great Phil. :clap
    #93
  14. Ras Thurlo

    Ras Thurlo Desert Lion

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    To all you guys that are sitting on the fence on this mod:

    this 100GS has a DRZ front end and stock paralever rear. It was my city bike and daily commuter, but now morphed into a 'true' scrambler.

    Have been riding this for last few weeks on/off road and can truly say its a 360 bike.

    [​IMG][/URL][/IMG]


    Front Bling

    [​IMG][/URL][/IMG]

    Rear Bling

    [​IMG][/URL][/IMG]
    #94
  15. Screaming Chicken

    Screaming Chicken Long timer

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    For values of stock that include an 18" wheel? :-)

    That is a fine bike...

    Still slightly on the fence about that fancy clamp. It's a hefty chunk of cash. But it's _nice_. :lol3
    #95
  16. elmontanero

    elmontanero Practicing...

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    I sent an inquiry to Race Tech here in Corona, CA. I asked about DRZ springs to go into my conversion.
    Two things that come up with the DRZ conversion : shortening the springs by 2.5 inches (~63mm) and using .60 kg/mm springs. Their response was :

    You would need the FRSP 435152 modded to 444mm in length which will give you a 2.5” shorter spring yielding a .60 kg/mm rate ($165.00).
    Anytime you make a fork shorter or go with a higher spring rate we would recommend addressing the valving as well.


    Things I know: the 435152 springs are .52 kg/mm. The 435152 standard length springs are available for much less than 165 bucks.:rofl

    Things I don't know: Will simply shortening the .52 springs give me what I want? :huh OR Do I need .60 springs shortened? :ear Anyone addressing the valving?

    I'd love to move the axle clamps up to keep spring length, but not sure about finding a shop here in San Diego to do so. Keep in mind that I'll be using either the DRZ triples or the HPMGuy triples with shims. I LOVE the Gullwing triples here but the exchange rate puts it out of my price comfort.

    THANKS!:D
    #96
  17. Prutser

    Prutser Long timer

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    Why would you like to have .60 springs ? Are you using a HPN tank?

    Lots of people ride their airheads with the stock drz valving and are happy with it. That might be because they don't know any better:lol3 But i would give it a try first so you can change the things you don't like later.
    #97
  18. Jim K in PA

    Jim K in PA Long timer Supporter

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    Cutting off coils will increase the spring rate, but whether or not it gives you what you want, only you will be able to say. Do you know what rate you are going for?

    Here is a good spring rate calculator: http://www.pontiacracing.net/js_coil_spring_rate.htm

    You can probably get an idea of the change in rate if you measure your springs and plug the data in. I doubt it will be more than 3-5% stiffer, given the high number of coils/unit length.
    #98
  19. Cdubs

    Cdubs made for adventure

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    Ras do you have any photos of your tach mount and headlight mounts? Im getting close to needing to fab some of that stuff :evil

    #99
  20. Ras Thurlo

    Ras Thurlo Desert Lion

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    Prutser's triples have the mushroom mounts for the stock head unit already fitted - so that part's kids play

    Will send some photos when I am back with the bike