RaceTech emulators in an Airhead - Help...

Discussion in 'Airheads' started by SamH, Nov 2, 2010.

  1. SamH

    SamH 90S on the bench

    Joined:
    Aug 14, 2005
    Oddometer:
    436
    Location:
    Tasmania, Australia
    I've just finished installing a set of RaceTech Cartridge emulators in my R90. I installed 90kg springs whilst I was at it as suggested by the dealer. After a bit of reading around I found installation instructions for the airhead forks and followed those (Cut the top off the damper rod, remove the check ball and spring, drill out the bottom holes and add two more, pvc spacers etc.)

    Now my forks feel like they're damn neer rigid... I mean I read that you can expect "Sports bike firm" forks but... I dunno, they're HARD and they don't seem to have any small bump compliance.

    I don't know if anyone on here's installed these things but if someone has, could you list your install process and any observations you might have on the feel afterwards?

    Hope someone can help

    Sam
    #1
  2. pommie john

    pommie john Long timer

    Joined:
    Apr 9, 2008
    Oddometer:
    1,544
    Location:
    Brisvegas, Australia
    I had a set of race tech emulators put in my airhead racer. OK , it has Marzocchi forks , but they used 10.5 kG/cm springs and when it arrived, it was far too stiff.
    I consulted another Race Tech place and they said to use 8.5 kg/cm springs.
    They improves things but the compression damping had been set too hard. The installer should have given you a spec sheet. Mine said that the compression damping was set at 3 turns, so I backed it off by two turns and it's good now.
    The 8.5 springs are about right.
    I think ( and you need to check) that they measure the turns from when there's no preload on the spring.
    #2
  3. pommie john

    pommie john Long timer

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    Oh yeah. The first job was done in Melbourne. He's totally useless.
    #3
  4. Dustdevill

    Dustdevill Adventurer

    Joined:
    May 16, 2009
    Oddometer:
    237
    Location:
    Middelburg, South Africa
    The springs you have fitted is likely to be the 0.9 kg/mm or 9 Nm spring.
    These are not progressive so the springs will be very stiff even over small bumps. You must look at it this way; it's a small trade of for firmer braking and handling.
    If you find the springs still to hard you can add a shorter spring on top of the Race Tech spring. This spring must not be longer than the spacer but can be shorter. Reduce the spacer length by the same as the newly installed spring length.

    Remember the more coils, the softer the spring will be.
    #4
  5. SamH

    SamH 90S on the bench

    Joined:
    Aug 14, 2005
    Oddometer:
    436
    Location:
    Tasmania, Australia
    All good points. I know that the forks will be considerably firmer but I don't know, they seem realy stiff. It could just be that they're so different. There's enough good press for the RaceTech gear that I'm sure I'll get it sorted.

    I realilsed that I haven't checked the fork alignment yet either, that may be adding some resistance.
    #5
  6. rkatapt

    rkatapt Indo-Kraut

    Joined:
    Jun 14, 2008
    Oddometer:
    263
    Location:
    Dallas, TX
    How long is your pvc spacer? I ask cause I got my racetechs and am unsure how much to cut the preload spacer.
    #6
  7. batoutoflahonda

    batoutoflahonda Long timer

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    Aug 8, 2007
    Oddometer:
    1,400
    Location:
    Easton Wa
    Simplest thing: Check the oil level. If it's got too much in they can hydro lock.

    Try taking most of the preload out of the emulator. Just use 1 turn or so.

    And, yes, check the sag and see what you're preload is.
    #7
  8. StephenB

    StephenB G(/)S ... what else!

    Joined:
    Aug 24, 2005
    Oddometer:
    2,045
    Location:
    Ontario
    I had the same issue with mine (too much on the stiff side) and experimented with stock spring, spring pre-load (different length spacers) and oil weight. Starting with Race Techs recommendation, I ended up with 1in shorter spacers, 1.25 rev out setting of the goldvalve and 7 weight oil. That made me a very happy camper.
    #8