Leading Link Designs - Post Pics

Discussion in 'Hacks' started by Pezz_gs, Feb 5, 2008.

  1. claude

    claude Sidecar Jockey

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    This IS kinda cool. However for off road it is probably better to have th ecaliper up on top. Just food for thought.Many of the trike folks use the plate as shown on the downtube in lieu of bending the fork tubes. We use double wall tubing for the fork tubes which are bent to whatever angle we feel is best for the application. Lots of ways to make aleading link happen no doubt. Floating calipers are the way to go though.
  2. boxertricks

    boxertricks Been here awhile

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    No I'm afraid not these were the only pictures I took.
  3. MILLENNIUM FALCON

    MILLENNIUM FALCON Been here awhile

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    .......what do you guys use for the joint at end of the fork legs (where the lower swing arm attaches? I have seen some bikes use ball (heim) joints, but was wondering what most are using. Bearings,bushings, or maybe just steel on steel. Any help...pictures would be awesome! Thanks!
  4. halflive

    halflive Been here awhile

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    Most common used are rubber bushes. The same kind as used in the A-arms of cars.
    [​IMG]
  5. zipper421

    zipper421 Been here awhile

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    are they two piece
    how do you weld them in with out them melting
  6. oppozit

    oppozit Banned

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    You don't! You use an interference fit to press them in, just like IMZ has done for decades.
  7. kshansen

    kshansen kshansen

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    On the front end I built back in 1992/93 I used the Heim joints, 3/4 inch with grease fittings. That front end has over 100,000 miles on it and I did replace them once.

    I do like the rubber car bushings idea, have to keep that in mind if I decide to build another front end for the XS400 project
  8. Bobmws

    Bobmws Curmudgeon At Large

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    You can buy high performance Polymer bushings instead of the standard rubber ones.They will have less play/flex in them.
  9. halflive

    halflive Been here awhile

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    Do the polymer bushes also have enough flex in them? The rubber bushes are also the hinge. They must be able to rotate about 15 degrees.
  10. claude

    claude Sidecar Jockey

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    We have used both and I prefer the heim ends. The ones we use are aircraft quality 3/4" x 3/4". No grease fittings. Weldnuts are wleded into the end of the fork tubes To receive these. You can play with camber on the front wheel a little using these by screwing them in and out.
  11. Slade 330

    Slade 330 Adventurer

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  12. Flodder

    Flodder Flodder

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    Thanks for the vidio and the isralite run. gotta get my act togather and put my chair on the 1400 i got from santa last xmas
    Cheers Flodder
  13. MILLENNIUM FALCON

    MILLENNIUM FALCON Been here awhile

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    Thank you for the info guys!


  14. NitroMax

    NitroMax Been here awhile

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  15. SINCAZ

    SINCAZ OUTBACK BUSH BASHER

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    Just going back to the basics.
    We want to reduce the trail or caster effect of the front wheel don't we ?
    First of all what trail are we aiming for ?
    1. Well what about remake the triple trees with a different fork angle to bring the wheel further forward ?
    2. On the leading link design do we want to get the main bent down tube vertical at the lower section and have the swing arm in the horizontal position ?
    3. Brakes. Floating or attached to the swing arm ?
    4. Main tube thickness 5 or 6 mm ?
    If I can't find the right tube diameter how about sleeving it to suit the triple tree ? ie 46 mm triple tree and using tube of 40 mm by 5 mm wall thickness and turning a sleeve of 6 mm and plug welding.
    Does this sound logical and safe ?
    Thanks for your input
  16. hahnda

    hahnda Been here awhile

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    I am no expert on Leading Link design but I have given it much thought and worked out a few designs that I intend to fabricate.

    1- This modification has been done with good results. Harley used to make "sidecar trees" that did just what you describe. This modification is typically called "raked trees". It reduces the trail but does not provide the rigidity of the leading link..
    2- I don't think it really matters if the downtube is vertical in the lower section but it does work well to design them that way. I do think that the wheel axle should be above the swingarm pivot. As an example think of a wheelbarrow. The wheel on the wheelbarrow is the wheel on the bike and your hands are the swingarm pivot. If you push the wheelbarrow along with your hands up high and you encounter an obstacle you risk the chance of dumping your load. Most people who regularly use a wheelbarrow will instinctively lower the handles when trying to go over an obstacle. This theory also works on the front of your motorcycle. That said you can find examples where the axle is above, in-line, or below. They all seem to work but in my opinion axle above the pivot is the best choice.
    3-Floating is probably best and will provide the best in braking. I had a Unit leading link where the calipers were on the swingarm. In hard braking situations the front end would raise up and have a tendency to skid across the pavement, especially when wet.
    4-I believe .120" wall or 3mm would be adequate on tubes over 40mm OD but there is also a tendency to use a tube within a tube to supposedly reduce resonance. I have seen leading link tubes shimmed in the way you describe but I not think that I have seen them that thick.
  17. mikejjmay

    mikejjmay Been here awhile

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    Put me on the list when you do Kevin!
  18. claude

    claude Sidecar Jockey

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    SINCAZ WROTE:
    Just going back to the basics.
    We want to reduce the trail or caster effect of the front wheel don't we ?
    First of all what trail are we aiming for ?
    RESPONSE:
    This is a personal preference. Some like less thna others. I ,personally do not care for too much of a trail reduction where road feel is moinimal or lost.
    SINCAZ WROTE:
    1. Well what about remake the triple trees with a different fork angle to bring the wheel further forward ?
    RESPONSE:
    This has been done on a regular baisis and it works well. Variations are to increase th eoiffset between th esteering head pivot and the fork tube location to move the whole fork assembly forward.
    SINCAZ WROTE:
    2. On the leading link design do we want to get the main bent down tube vertical at the lower section and have the swing arm in the horizontal position ?
    RESPONSE:
    I don't feel that the fork tube being vertical is much of a rtequirement to a good design. As far as the swingarm being horizontal goes that is good for appearance but th eidea of having the axle higher than the swingarm pivots , as Kevin mentioned, is what counts.
    SINCAZ WROTE:
    3. Brakes. Floating or attached to the swing arm ?
    Floating is better. Kevin explained this quite well.
    SINCAZ WROTE:
    4. Main tube thickness 5 or 6 mm ?
    RESPONSE:
    We use a double walled forl tube. usually 1 1/2' x .120 on the outside with 1 1/4" inside of it.
    SINCAZ WROTE:
    If I can't find the right tube diameter how about sleeving it to suit the triple tree ? ie 46 mm triple tree and using tube of 40 mm by 5 mm wall thickness and turning a sleeve of 6 mm and plug welding.
    Does this sound logical and safe ?
    RESPONSE:
    Sleeving is fine.
    Thanks for your input
  19. NitroMax

    NitroMax Been here awhile

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    Finished leading links, picked it up from the painters yesterdag evening:

    [​IMG]

    [​IMG]

    Works ( and looks ) great :clap
  20. dholaday

    dholaday Been here awhile

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    If you go to this page, you will see an interesting new design EZS has used on a K1600GTL. They say it will also work on a GT and that it preserves location and function of the stock shock.

    http://www.ezs-sidecar.com/en/news-dutch/75-de-eerste-k1600gtl

    A K1600 would make a fun rig - probably has enough HP and torque to move things right along.

    Duncan