swing-arm as leading link

Discussion in 'Hacks' started by mantree, Sep 6, 2017.

  1. mantree

    mantree Been here awhile

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    Has anyone ever considered using a swing arm from a motorcycle as part of leading links? I was thinking of using the swing arm from a CB750k. This would greatly simplify construction as well as make for a bit of adjustment.
    #1
  2. Pigeon

    Pigeon because white owl was taken

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    yeah I have considered how it could be done since I have just the fork from an earles setup.been looking on ebay at older sportster swingarms as they are symmetrical and can be easily modified. However I've concluded nothing.
    #2
  3. Old Mule

    Old Mule Long timer

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    Usually rear swing arms are too long. You don't need chain adjustment, so the slots are redundant. The shock mounts might not be in the right place. Neither would caliper mounts. If you stantions are designed right, you won't need to adjust trail. A fab shop or local hot rod shop could make you a swing arm that was juuussssst right for not much money.
    #3
  4. davebig

    davebig Another Angry Hun !

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    Sportster swingarms
    Forged joints and heavy are what I see, since most US builders use tube within a tube for double wall construction of LL legs the finished forks are way heavier than what they are replacing easily 2x as heavy. They are hard on shocks so keeping unsprung weight down may be a value.
    #4
  5. vortexau

    vortexau Outside the Pod-bay

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    I have seen fork leg lowers (sliders) hollowed out and converted into Leading Links. The original axle and brakes go back into place, unless the calipers are to be anchored so as to not cause front-end rise under braking. It may be possible to use a heavy-duty fork brace as the "U-bend" section of the build, but some reinforcing may be required as a normal Fork Brace was not designed for this sort of loads.

    Here's a pic (lower leg with fork brace) to start the mind working :

    [​IMG]
    #5
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  6. Pigeon

    Pigeon because white owl was taken

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    WELL... That opens up a slew of possible scenarios
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  7. claude

    claude Sidecar Jockey

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    Build it stout. VERY important. ,......................................................................................................................................................................[​IMG]
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  8. Bobmws

    Bobmws Curmudgeon At Large

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    ^^^ I guess the low seat option wasn't low enough! :dunno
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  9. FR700

    FR700 Heckler ™©®

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    Ask AL‐58, it's his old K'.
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  10. Bobmws

    Bobmws Curmudgeon At Large

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    AL-58 what was the cause of the failure?
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  11. mantree

    mantree Been here awhile

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    I was planing on a lot of bracing to avoid that type of failure

    Sent from my SM-G900V using Tapatalk
    #11
  12. davebig

    davebig Another Angry Hun !

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    Did I forget to say most of the US sidecar builders use double wall tube within a tube construction on leading links
    #12
  13. mantree

    mantree Been here awhile

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    I was actually thinking of doing something similar to what Cleatusj did for his legs

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    #13
  14. BigFatAl

    BigFatAl Been here awhile

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    Gordon Scott did a set of leading links for his XS650 several years ago using a XS650 swing arm, ( modified of course )worked great.
    [​IMG]


    Sent from my iPhone using Tapatalk
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  15. claude

    claude Sidecar Jockey

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    btw rear swingarms includng bmw mono levers have been used to build leading link ftont ends.
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  16. claude

    claude Sidecar Jockey

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    Actually, if I recall, he had been out or a ride and had just pulled into a place (bidy shop if I recall?) when the front end broke. Thin tubing.
    #16
  17. FR700

    FR700 Heckler ™©®

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    "Thin tubing" pretty much as I recall, although, I seem to remember it happened in his own drive. Stripped it, then made one outfit of the two K's that he had.


    http://advrider.com/index.php?threads/leading-link-designs-post-pics.308801/page-8#post-10835768

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  18. claude

    claude Sidecar Jockey

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    I used to have some close up pics of the break. The tubing was thin. Thank God it happened the way it did and not on the road.
    #18
  19. mantree

    mantree Been here awhile

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    My plan was to use dom tubing. I have used it in rock sliders on my trucks a lot and I have seen it used in roll cages. Then I will brace everything with 1/4 inch thick plate

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    #19
  20. bk brkr baker

    bk brkr baker Long timer

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    Dom inside Dom is the ticket.
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