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Thread: Race chassis

  1. #1366
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    19th October 2014 - 17:49
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    whatever I can get running - dirt/track/
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    I used that same exhaust on all 5 versions of the bike it wasn't broken so I didn't fix it.



    I eventually added a horizontal panel in the back section of the tank to get a bit more fuel capacity. P. Williams-style pannier tanks would have been another option.

    I've some nice photos of the Ogier Hossack that Norman sent me here:

    http://www.eurospares.com/hossack.htm

  2. #1367
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    25th March 2004 - 17:22
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    Despite being a dirty 4 stroke that Laverda looks great.

    It reminds me of a daydream two days ago of what one would have done if left in charge of Triumph late 60s with no ability to design an engine but an otherwise obsolete product and looming competition. That would be a good starting point. Clearly with road gear.
    Don't you look at my accountant.
    He's the only one I've got.

  3. #1368
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    20th January 2010 - 14:41
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    husaberg
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    A while back we were talking abou the Plasma coated Aluminium brake discs that MV Augusta (Among others such as Kawasaki)used to run on the racers.
    Looking through a Motorcourse from 1984 it looks like most of the 125's used to run Zanzani Brake discs.
    http://www.motobi.com/zanzani_2015/dischi.html
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    Other interesting tidbit was even back then Honda were running carbon discs on the works supported NS500 and NSR500's
    Quote Originally Posted by Katman View Post
    I reminder distinctly .




    Kinky is using a feather. Perverted is using the whole chicken

  4. #1369
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    20th April 2011 - 08:45
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    How about 3D-printing a frame?
    https://www.asphaltandrubber.com/new...printed-frame/
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    Surprisingly there is still some welding at the headstock.
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  5. #1370
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    24th July 2006 - 11:53
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    Quote Originally Posted by Frits Overmars View Post
    How about 3D-printing a frame?
    https://www.asphaltandrubber.com/new...printed-frame/


    Surprisingly there is still some welding at the headstock.
    Probably the only section requiring resolution better than the printer can provide, (bearing cavities).

    I'd love to see the FEA work on that, I assume most if not all of the sections are hollow, in which case it looks like the result of a proper force diagram approach.
    Go soothingly on the grease mud, as there lurks the skid demon

  6. #1371
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    8th July 2013 - 11:01
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    Bearing cavities will be machined after printing, so not a resolution issue.

    It is probably as simple as being the limit of the build envelope for the printer. Too big, so needs to be done in two parts.

  7. #1372
    Quote Originally Posted by Ocean1 View Post
    I'd love to see the FEA work on that, I assume most if not all of the sections are hollow, in which case it looks like the result of a proper force diagram approach.
    Will be the result of topology optimisation:

    https://solidthinking.com/inspire2018.html

    I think there is a great case for creating a chassis from folded topology optimised sheet metal.
    Most frames are made with complex manufacturing methods which allow for a wide range of geometries, but are limited by the designers ability to consider more than a few variables at once (ending up overweight and over/under stiff in some modes), and require a great deal of time to manufacture. But with an optimised sheet metal construction, a lighter chassis with the required stiffnesses could be quickly and repeatably manufactured for only a few hundred dollars, especially if it was made to be self-jigging.

  8. #1373
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    24th July 2006 - 11:53
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    Quote Originally Posted by monkeyfumi View Post
    Bearing cavities will be machined after printing, so not a resolution issue.

    It is probably as simple as being the limit of the build envelope for the printer. Too big, so needs to be done in two parts.
    Yes, I was simply pointing out that the printer wouldn't provide H7 level tolerances.

    And yes, the constraint will be the capacity of either the printer or the machine center.
    Go soothingly on the grease mud, as there lurks the skid demon

  9. #1374
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    24th July 2006 - 11:53
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    Quote Originally Posted by Moooools View Post
    Will be the result of topology optimisation:

    https://solidthinking.com/inspire2018.html

    I think there is a great case for creating a chassis from folded topology optimised sheet metal.
    Most frames are made with complex manufacturing methods which allow for a wide range of geometries, but are limited by the designers ability to consider more than a few variables at once (ending up overweight and over/under stiff in some modes), and require a great deal of time to manufacture. But with an optimised sheet metal construction, a lighter chassis with the required stiffnesses could be quickly and repeatably manufactured for only a few hundred dollars, especially if it was made to be self-jigging.
    It's certainly got that avian bone structure look. Wonder if this year's budget will handle some CAD upgrades.

    Aye, monocoque structures are not only comparatively inexpensive but often seem to be a bit more... damage tolerant.
    Go soothingly on the grease mud, as there lurks the skid demon

  10. #1375
    Join Date
    2nd March 2013 - 15:04
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    This is interesting

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    The Kawasaki 250 engine is just a place-holder. It's designed to take a Ducati V-twin. The shocks are MTB.

  11. #1376
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    13th June 2010 - 17:47
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    Well, it's certainly different. But I find it difficult to see the rationale behind it. It looks to me like the rear transverse bulkhead off a race car. But more complicated...
    The rear geometry looks to me like it would lift under power - the heavily angled top link will transfer a lot of weight to the rear tyre which will lift the back of the chassis IMO.
    The front appears to be designed to increase trail as it dips. Opposite to conventional teles which use the reducing trail to assist turning.

    I'd have liked to see the builder's reasoning behind it.

  12. #1377
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    20th April 2011 - 08:45
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    Quote Originally Posted by Grumph View Post
    The rear geometry looks to me like it would lift under power - the heavily angled top link will transfer a lot of weight to the rear tyre which will lift the back of the chassis IMO.
    The front appears to be designed to increase trail as it dips. Opposite to conventional teles which use the reducing trail to assist turning.
    I'd have liked to see the builder's reasoning behind it.
    I think trail will decrease when the front dips, but I don't think you could ever persuade it to dip; it looks like a massive amount of built-in antidive at the front and antisquat at the back. And I fear there is next to zero torsion stiffness in all directions. Let's just consider it a work of art .

  13. #1378
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    Quote Originally Posted by Frits Overmars View Post
    I think trail will decrease when the front dips, but I don't think you could ever persuade it to dip; it looks like a massive amount of built-in antidive at the front and antisquat at the back. And I fear there is next to zero torsion rigidity in all directions. Let's just consider it a work of art .
    Works for me....

  14. #1379
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    25th March 2004 - 17:22
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    Well funnily enough I bumped into this tonight. It does look great. A mate Roger had told me he was going to something like this. He is a Tesi owner.
    Water jet some of it but largely by hand

    2 bikes in the background now I look at this. One known for real bad handling. One for real good.
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    Don't you look at my accountant.
    He's the only one I've got.

  15. #1380
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    13th June 2010 - 17:47
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    Is it "Roger from Greytown" - or another one ?

    Being a Tesi owner answers some questions...

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