R1100GS HP1 Conversion on the cheap!

Discussion in 'GS Boxers' started by gristone, Nov 23, 2008.

  1. gristone

    gristone Adventurer

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    In order to use the left fork leg on the right side so that I can run dual discs I needed to bore it out to 25mm for the shouldered side of the axle. I did a sketch and sent it to my friend in LA that I sold my milling machine to when I moved to NY and had to downsize. Here is the sketch showing what needed to be done.

    Attached Files:

    #21
  2. gristone

    gristone Adventurer

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    Here is what he recommended:

    Attached Files:

    • dino.jpg
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    #22
  3. gristone

    gristone Adventurer

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    needless to say it worked out pretty well despite the high cost of the special Dino-Alloy he had to use.
    #23
  4. JimVonBaden

    JimVonBaden "Cool" Aid!

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    :lurk

    Jim :brow
    #24
  5. mousitsas

    mousitsas Long timer

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    gristone,

    Excellent job! I have one question for you though, as i am thinking of a similar conversion, but without having your welding skills. Have you looked into the possibility of using the original aluminum front frame with the appropriate bracing using the telelever mounts? And of course fabricating and welding a piece for the triple tree.

    Due to the original design, the stock head is stong on axial forces but lacking in torsional since the telelever arm takes care of them. So I think that the addition of a suitable triangular element at the telelever mounts and a bit of cross bracing would do the job.

    Am i wrong?

    m.
    #25
  6. drlukas

    drlukas Adventurer

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    Great job
    #26
  7. gristone

    gristone Adventurer

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    Yes, I actually pursued that option extensively because I had a Cannondale frame and Ohlins front end that would have been easily kluged into the stock headstock (still would have involved a bunch of welding) but I trust chromoly a lot more than aluminum. And it would have required so much additional reinforcement that it started to look really ugly. I saw a post on here from a guy in Australia (I think) that used the original casting and just added to it and it ended up needing a different tank and seat because of how he tied it in to the rear subframe for stability. It looked really cool and it seemed like it worked out for him pretty well, but one of my criteria when I started this was to use the Touratech tank and maintain as much of the stock equipment as possible.

    If you are interested I would sell the Cannondale frame. I think I still have a spare triple for it as well, but I sold the Ohlins.
    #27
  8. mousitsas

    mousitsas Long timer

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    I am aware of that bike. Your point on aluminum vs chromoly is correct for sure, but i had in mind a different approach. One that would just use the original front frame as a core structure and build around it, so tank and fittings would be the same.

    Regarding the frame, i might get back to you after i fully explore the above approach!
    #28
  9. Vaskar

    Vaskar Been here awhile

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    Any news of this project ???
    #29
  10. xlv

    xlv Been here awhile

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    I´d like to see more of this build







    pretty please!
    #30
  11. LukasM

    LukasM Long timer

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    Fantastic fabrication! :clap

    In his last post gristone was trying to buy a KTM LC8 fork so I guess he is still on it.

    Subscribed.
    #31
  12. Rode2Nowhere

    Rode2Nowhere Long timer

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    Jeez... forgot I signed up for this thing...

    :lurk :lurk :lurk :lurk
    #32
  13. gristone

    gristone Adventurer

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    [​IMG]

    [​IMG]

    [​IMG]
    I milled a little area on the headstock for the serial number which I stamped by hand with some steel stamps. It actually looks mostly legit.

    [​IMG]

    [​IMG]

    [​IMG]


    I'll take some pics of the steering damper mount I made and the rear end with lights and stuff. I still need to get a fairing and some headlights.
    #33
  14. Johnnyboxer

    Johnnyboxer Long timer

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    Looks great:clap
    #34
  15. JimVonBaden

    JimVonBaden "Cool" Aid!

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    Nice work!:thumb

    Just two questions. Is there adequate room for a 21" rim, and is it just the photos, or is the fork angle a bit steep?

    Jim :brow
    #35
  16. Ricardo Kuhn

    Ricardo Kuhn a.k.a. Mr Rico Suave

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    Gristone that is some wonderful work you have done, far superior than the Niko bekker/Bursma attempts, then poorly copy here by some call "Members"

    I do have a question, how did you calculate the location and angle of the steering column.??

    It looks pretty step on the pictures but maybe is just a optical illusion.

    Second question, are you planing to make some of them for sale? if that is the case hopefully I can become one of the owners.

    Again wonderful work, not only for the fabrication skills but the innovative approach to the space constrains, please keep the pictures coming
    #36
  17. hasenwerk

    hasenwerk Long timer

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    +1 on that! :wink:
    #37
  18. gristone

    gristone Adventurer

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    Fork angle is a little bit steeper than stock--2.5 degrees on the protractor. The pictures do make it look unusually steeper than it actually is.
    I did this because I read an article that intrigued me and I wanted to try something a bit different.
    Here is a link to the article:
    http://www.tonyfoale.com/Articles/RakeEx/RakeEx.htm

    It really sounds like there is only beneficial factors attributed to steeper steering angles...IF...you have forks that withstand the forces associated with braking-- which I feel the 48mm WP's can probably handle pretty well. We'll see in a few weeks.
    And yes, you can mount a 21" dirt tire and still clear the pipes and front cover with a couple of inches.

    With the stock frame mounted in place I made a fixture that would support the new steering tube and allow me to change the rake by a couple of degrees. see earlier pictures in this post.
    #38
  19. Vaskar

    Vaskar Been here awhile

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    I know that this is an old post, but what happened ???
    #39
  20. Vaskar

    Vaskar Been here awhile

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    +1 on that !!!!!
    #40