TAG frame mods

Discussion in 'Airheads' started by Ras Thurlo, Jan 30, 2013.

  1. Airhead Wrangler

    Airhead Wrangler Long timer

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    Yeah, I didn't word that very clearly. The swingarm has greater leverage to compress the shock (or so I'm assuming from photos without actually measuring it and doing calcs). This results in greater axial force in the shock which requires a heavier spring rate. That greater force has to be transmitted to the main frame somehow and would require much sturdier means of mounting the shock, hence HPN's shock "subframe" with three points of connection to the main frame.
    #41
  2. Ras Thurlo

    Ras Thurlo Desert Lion

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    got it

    by the sounds of things the difference between the HPN and the TAG approach is within the realms of subjectivity
    #42
  3. Airhead Wrangler

    Airhead Wrangler Long timer

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    Probably. I'd just ask them how hard and for how long they've beat on them and if they've ever broken anything. It's not exactly scientific, but that's all that really matters in the end. The differences in their approach to reducing the wheel offset as well as frame stiffening remain to be seen though. Let us know what you find about about how they do it. More than one way to skin a cat, as they say.
    #43
  4. CrazyIvan

    CrazyIvan Vonkentrekker

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    It's definitely not dead center. I'm building one a the moment, if you wan't to use a 140 rear tyre you will end up with about 15mm offset.

    That is with the swingarm moved as far as possible to the right, and the engine moved to the right also.

    The guy who has build my rear wheel used the HPN sport specs for offset.

    If you go the monolever route, you will probably end up in the same ballpark, to use a 140 tyre the wheel needs to be spoked out of center 10mm or more.

    [​IMG]

    [​IMG]
    #44
  5. Airhead Wrangler

    Airhead Wrangler Long timer

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    Feel free to tell us more about that. Looking very nice. :tb
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  6. Ras Thurlo

    Ras Thurlo Desert Lion

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    thats destroyed an urban myth for me that the 1100 paralever sucks because of the offset!

    how does it ride with the engine move to the right? Is the assumption right that engine move has less effect on handling than the offset you are curing?

    My take away from your comments are that since I have my frame with the TAG guys anyway, I might as well move my engine mounting and get the vespa vibe. This will give me less offset with a 140 set up on a monolever and will give optionality for a para conversion.
    #46
  7. CrazyIvan

    CrazyIvan Vonkentrekker

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    Steady on !

    The only thing you need to change are the engine spacers. You just move the engine to the right by 3 or 4 mm.
    The engine needs to move a bit to get a better alignment with the 1100 swingarm.

    You might want to grind off a mm or so of the tab where the centre stand spring attaches.
    #47
  8. Phreaky Phil

    Phreaky Phil Long timer

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    In the top pic they are using the airhead drum brake final drive so alignment should be no problem
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  9. Timpo

    Timpo NORTH WALES TRF.

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    Quality..... I knew that was coming!.......:lol3
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  10. Ras Thurlo

    Ras Thurlo Desert Lion

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    any of you out there have an extended monolever with offset rim for a 140 tyre?

    How is the handling?
    #50
  11. Ras Thurlo

    Ras Thurlo Desert Lion

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    A couple of you have asked for more info on the TAG monolever:

    standard +100mm length, aluminium, shock mounting point on swingarm allows for a shock that is the same dimensions as the standard shock and they sell an Ohlins designed to go onto it (see photo).

    The HPN/Moorespeed monos have the mounting point a bunch further back. Does this approach give more 'control' because of lower lever pressure?

    The interesting thing is that the TAG swingarm is angled at 6 degrees to the right, so that you can offset your rim for a 140 tyre and not have too much overall wheel offset.

    From what I had understood on a 'standard' extended mono, you need to offset your rim the approx 12-14mm from center-line to clear a 140.

    With the TAG design you have approx 10mm of play on your rim offset to get back to centreline, so resulting in an approx 2-4mm offset.

    They said that there is not enough width at the gearbox end to allow for a greater angling of the mono that would totally remove this offset.

    does this all make sense?


    [​IMG]


    [​IMG]


    it comes with this 'stub' driveshaft that is made to be welded to a standard mono driveshaft

    [​IMG]
    #51
  12. Desertpistons

    Desertpistons 80s dakar

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    Howdy,

    I am learning some Texan :)

    Having played with tag arms for more than 10 years, will give you my 2 cents.

    I like them but they are more delicate that the elongated steel swimgarm ala HPN. Steel vs alum fusion. That said...I never had any problem with them.

    I know of people that cracked the swing arm but they didnt follow Tag's recommendation mods to the frame and they didn't respect the schock travel which is max 270. Ezio will tell you 260 mm because h wants to play safe:)

    If i have to pick between the 2 and money is not issue go definitely with the TAG arm. Are you kidding me?
    I know that TAG had some of them reinforced...buy adding some addl materials in certain areas -check out my bike and look very closely to my swingarm:

    http://www.desertpistons.com/4strokesd/TAG/Tagindex.htm

    I miss the lira...everything now is double with the Euro in Italy...

    Tag bikes and set up have been tested and tested and tested and tested and tested and tested in racing competitions by enduro professional racers so you will not have a problem with what Ezio set you up with.

    The last TAG bikes have an oilhead swingarm with the shock attachment done on the side as the monolever does. Since i have never heard of them having any issues, I have copied the set up and will test my last shortstroke enduro in few months. I will ill report on this. Having cracked BMW reinforced frames in the past, i know i will test it right...:)




    #52
  13. Airhead Wrangler

    Airhead Wrangler Long timer

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  14. igormortis

    igormortis Cafe Reise

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  15. Prutser

    Prutser Long timer

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    I'm using a 140 tire on my ST rim size 2.50x18"
    The handling is fine and it is almost the same as when I use a stock wheel.
    #55
  16. Beater

    Beater The Bavarian Butcher

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    How far did you have to dish the rim over? 12mm? You relaced with Excels right?
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  17. Prutser

    Prutser Long timer

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    I think its 9mm with the excels on my bike.
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  18. Airhead Wrangler

    Airhead Wrangler Long timer

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    That's with a 2.5" x 18" excel?
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  19. Ras Thurlo

    Ras Thurlo Desert Lion

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    do the excel rim nipples cope well with the offset? Or do you have to bend the spokes a bit?
    #59
  20. Prutser

    Prutser Long timer

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    @ Ras No need to bend the spokes.
    @ Airhead Wrangler Yes the 2.5 x 18" excels
    @ Beater I got two off-set wheels With one I use a spacer of 5mm thick. I have to measure them to give you the real
    off-set. I will let you know a.s.a.p.
    #60