PROJECT: 76 R75/6 Cafe

Discussion in 'Airheads' started by sparkymoto, Dec 23, 2009.

  1. sparkymoto

    sparkymoto Learning a lot here

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    I can totally get behind the quality of this brace. ToasterTan does his homework.

    One more fancy-foto before installing...

    [​IMG]

    Installed...

    [​IMG]
  2. Houseoffubar

    Houseoffubar HoFmetalworks.com

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    Damn that looks great!!!!!!!!!!!!!!!!!!!!!!!!!!
  3. VietHorse

    VietHorse Long timer

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    That too beautiful to me! Thanks for the great idea and awesome design.
    I may also put my name or nick name somewhere like yours.

    Yeah, I can see quite many guys has that modification though. However, there is none of them leave comment on the performance.

    May you please tell me why you choose the option 1 rather than option 2 as in below sketch?

    [​IMG]
  4. sparkymoto

    sparkymoto Learning a lot here

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    PM'd you with links and info :thumb
  5. Toaster.Tan

    Toaster.Tan Toaster Rider

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    I agree with only some of what you say, SuperShaft....
    Yes, loads are transmitted into the center stem, however, that stem is designed with two sets of bearings that are more than capable to take them, center the stem - and still provide rotation of the forks! This design has been used successfully on applications that have significantly more stress and lasted for 30 plus years!

    The wallowing of the top brace center hole is from the forces transmitted by the fork legs - not the center stem. The forks are constantly trying to twist the top plate in opposite directions and that force is exponential because the stanchions fulcrum off the lower brace - into the top plate - which pivots against the center stem. It's all about suppressing the loads from the stanchions transmitting to the stem - not the grip on the center stem. I can only speak for my design, which specifically absorbs the loads at the stanchion top and significantly reduces the amount transmitted to the stem by making it rigid. You can never eliminate it, but can bring it down to an amount that is easily handled by the stem acorn nut.

    I agree with you the center acorn nut shoulder is woefully lacking in depth and would like a longer one, but if the loads are brought down enough it's adequate for the job. You can see the amount of threads engaged on my brace when the acorn is seated - plus another couple turns in the depth of the shoulder. However, with my brace the nut is no longer 'holding' the top plate in place - its mostly centering the brace to the stem. It all works together to create a rigid fork and provide improved handling and a more planted front end


    [​IMG][​IMG]

    Stephen
  6. Toaster.Tan

    Toaster.Tan Toaster Rider

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    That was my first try at embedding photos. Don't know how to get them larger and clear.....
    Have to work on that I guess.

    Stephen
    :D
  7. Toaster.Tan

    Toaster.Tan Toaster Rider

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  8. sparkymoto

    sparkymoto Learning a lot here

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    Cool. How 'bout starting a separate thread for the product and your pics and open it up there for discussion.
  9. Toaster.Tan

    Toaster.Tan Toaster Rider

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    Good advice Sparky,
    I'm uncomfortable with posting my stuff here as it looks too much like hawking the brace, but the questions/comments are legitimate. I'll stop the thread here.

    Back to YOUR stuff! What have you done to the end caps? Did you put some sort of spacer there? I'd like to see a closeup of that.

    Stephen
  10. Toaster.Tan

    Toaster.Tan Toaster Rider

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    AND.... Does the center bolt in the stem acorn nut go all the way through and engage the damper? Do you have any constant drag on the steering movement for stability? I've seen cafe's with the separate side damper rods installed.
  11. supershaft

    supershaft because I can

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    Not the center stem? Who are you arguing with? Of course the loads come from the fork tubes. They are connected to the sliders and they are connected to the axle and the axle is connected to the wheel.

    Sorry but your design absorbs virtually no load. If it did it would be getting hot. Energy doesn't just disappear. What your design does do is transfer the loads to the stem. The stem transfers the loads to the bearings and the bearings transfer the load to the frame. The suspension absorbs some load but that is dis . . . . I got to go help my shop landlord unload his new used Ferrari. I'll be back later.

    Well, that wasn't too bad but the thing has almost no ground clearance.

    . . . Dissapated through heat. The trees have almost nothing to do with suppressing loads and almost everything to do with transferring loads to the stem. Big Diff! Hence the need for a wider surface to transfer the loads. The whole reasoning behind annulused spacers: Leverage.

    You can only speak of your design? Your design? Come on please. It's triple tree!

    Your tree is just like the stock tree in that it transfers the load from the fork tubes to the steering stem through the steering stem lock nut. It absorbs no load to speak of. It in fact absorbs less than the stock tree if it doesn't flex as much and I am betting that it doesn't.

    They are great looking trees but they don't fix a IMO design weakness of the original design. Exactly where I have seen a lot of problems with the stock trees. I have got a better tree. Now I am going to come up with a better way to transfer the loads from the tree to the stem.
  12. VietHorse

    VietHorse Long timer

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    Well, Sparkymoto, you were right when talking about opinions.
    Thanks and appreciate that.
  13. sparkymoto

    sparkymoto Learning a lot here

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    :D

    Looking forward to what you come up with. Let us know how it goes!
  14. VietHorse

    VietHorse Long timer

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    Yeah. I am also curious... :evil
  15. adrenal

    adrenal skrunkwerks.com

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    Some nice stuff being shown here....couldn't resist popping mine in. (apologies for the thread hyjack sparky:augie ).
    Started as a personal project then ended up making a handful for people converting airheads down here in Aussieland. They certainly make a difference! This was an earlier version. The later ones are the same but thicker plate with a recess underneath for the middle locking nut so that not too much thread length is stollen from the top nut - notice it's missing its dome.. didn't like the look of it so I milled it off! I always use a couple drops of locktite on this nut.

    Made them mostly without the holes as people doing the clipon thing. In my case I reused a modified instrument bracket so the holes stayed.

    Love what you did with that bike sparky. fraid I'll have to steal the rear tailpiece idea for my next build- sincerest form of flattery you know :D


    [​IMG]


    [​IMG]
  16. blaine.hale

    blaine.hale Long timer

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    I like how you've started the unofficial top tripple tree clamp thread :rofl
  17. sparkymoto

    sparkymoto Learning a lot here

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    :p3rry
  18. Darbone85737

    Darbone85737 Adventurer

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    on my RS90 custom.... with KYB inverted forks. Seemed foolish to me to use massive clamps on spindly fork tubes, but that's just me

    [​IMG]

    [​IMG]
  19. adrenal

    adrenal skrunkwerks.com

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    oops.

    Hey sparky! Nice bike!

    (there...back on track)
  20. sparkymoto

    sparkymoto Learning a lot here

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