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1964 Matchless G15 MK2

Discussion in 'Other Norton Motorcycles' started by pierodn, Sep 12, 2019.

  1. pierodn

    pierodn

    Joined:
    Nov 10, 2012
    Ciao.
    My Roadholder forks dont have the internal springs, the dampers are without!
    The springs are external.
    Maybe it is right but my 1967 N15 has the internal springs only.
    Let me understand better.
    Thank you.
    Piero
     
    Last edited: Sep 12, 2019
  2. mdt-son

    mdt-son

    Joined:
    Jan 19, 2012
    Hi Piero,
    Neither is right according to my information. The CS had special internals and external springs, because the Norton roadster set-up doesn't work well in the rough. For 1967 even the CS became "civilised" and had the same internals as the roadsters. This is in full agreement with the spares book.

    -Knut
     
  3. pierodn

    pierodn

    Joined:
    Nov 10, 2012
    Hi Knut.
    You mean that i must fit the internal springs too?.
    Thank you.
    Piero
     
    Last edited: Sep 12, 2019
  4. Bernhard

    Bernhard

    Joined:
    Apr 20, 2011
    The short answer is no- it looks like some previous owner converted your forks to the “Manx look”
     
  5. mdt-son

    mdt-son

    Joined:
    Jan 19, 2012
    You are not obliged to, but I would do it, if only to make the bike like it was when it left the factory. The 1964-66 CS set-up (if that's what you have) may provide a harsh riding experience on pavement. This is my guess, but it's up to you. Beyond the riding experience, when fitting external springs, there is always friction between spring an fork tube which will damage the chrome in the long run.

    -Knut
     
  6. pierodn

    pierodn

    Joined:
    Nov 10, 2012
    Hi Knut.
    I will fit internal and external springs.
    The question is if the G15 internal springs lenght is the same of the commando or is longer because the stanchions and dampers are longer like N15 (mine has the stanchions and the dampers longer than commando).
    Let me know please.
    Thanks
    Piero
     
    Last edited: Sep 14, 2019
  7. mdt-son

    mdt-son

    Joined:
    Jan 19, 2012
    The G15 Mk2 (roadster) spring length is identical to that of the 1968 Commando (NM18813 = 06-7723).
    Damper 03-0037 was 1" longer than damper used in Atlas/Mercury (650). It seems Commando damper tubes are slightly longer than 03-0037 and threads are different. Damper rod NM15801 was identical betweem Dominators and the G15 lineup - damper rod off the Commando has different thread and possibly different length (likely shorter than the former).

    Please have a look in the 1965 supplementary list for G15CSR. The 1964 list has some errors in the fork department.

    Helpful notes are given by Anthony Curzon (aka John Donne) in this link:
    http://www.jampot.com/forum/viewtopic.php?f=22&t=11335

    I hope this helps.

    Cheers,
    Knut
     
  8. mdt-son

    mdt-son

    Joined:
    Jan 19, 2012
    I don't think you will be very happy by your choice. Let's assume inner and outer springs have the same spring stiffness (k1, k2 respectively).
    Then, the combined spring stiffness is k = k1 + k2 = 2*k1 according to our prerequisite.
    So, spring stiffness will be twice as stiff as the factory setup. In reality it will be even stiffer.

    Regards,
    Knut
     
    Last edited: Sep 15, 2019 at 5:04 PM
  9. pierodn

    pierodn

    Joined:
    Nov 10, 2012
    Hi Knut.
    I understand.
    The final question is:
    -to leave the external springs (without internals as i have found in);
    -to fit the internal springs only without external.
    Thanks for the help.
    Piero
     
  10. mdt-son

    mdt-son

    Joined:
    Jan 19, 2012
    Piero,

    I can't relieve you of this discision, but knowing that the G15's (minus the G15 Scrambler), the Atlas and the Commando faired well with internal springs, I would trust this solution.

    Rgds. Knut
     
  11. pierodn

    pierodn

    Joined:
    Nov 10, 2012
    Hi Knut.
    Thank you.
    Piero
     

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